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1
Mondal, Sukanto. "Horizontal alignment optimization in road design." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/47152.
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The horizontal alignment optimization problem in road design is a complex problem. Usually, classic optimization techniques cannot be used to address the problem. A few studies investigated the problem mainly using heuristics. Unfortunately, all of the previously studied heuristic based methods do not guarantee optimality. In this study, we develop a novel optimization model to solve the horizontal alignment optimization problem in a specified corridor. The cost of a horizontal alignment is significantly affected by the associated vertical alignment cost. So in order to formulate the cost function of the model, we consider both the vertical alignment and earthwork allocation associated with a horizontal alignment. The representation of a horizontal alignment in our model satisfies all of the geometrical specifications used by engineers. Our model is suitable for both backtracking and non-backtracking horizontal alignments. Derivative-free optimization algorithms are used to solve the problem and guarantee the local optimality of our solution. The numerical experiment results of a set of practical problems are reported.Graduate Studies, College of (Okanagan)
Graduate
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Duran, Serhat. "Computer-aided Design Of Horizontal-axis Wind Turbine Blades." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605790/index.pdf.
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Designing horizontal-axis wind turbine (HAWT) blades to achieve satisfactory
levels of performance starts with knowledge of the aerodynamic forces acting on
the blades. In this thesis, HAWT blade design is studied from the aspect of
aerodynamic view and the basic principles of the aerodynamic behaviors of
HAWTs are investigated.
Blade-element momentum theory (BEM) known as also strip theory, which is
the current mainstay of aerodynamic design and analysis of HAWT blades, is used
for HAWT blade design in this thesis.
Firstly, blade design procedure for an optimum rotor according to BEM theory
is performed. Then designed blade shape is modified such that modified blade will
be lightly loaded regarding the highly loaded of the designed blade and power
prediction of modified blade is analyzed. When the designed blade shape is
modified, it is seen that the power extracted from the wind is reduced about 10%
and the length of modified blade is increased about 5% for the same required
power.
BLADESIGN which is a user-interface computer program for HAWT blade
design is written. It gives blade geometry parameters (chord-length and twist
distributions) and design conditions (design tip-speed ratio, design power
coefficient and rotor diameter) for the following inputspower required from a turbine, number of blades, design wind velocity and blade profile type (airfoil type). The program can be used by anyone who may not be intimately concerned with the concepts of blade design procedure and the results taken from the program can be used for further studies.
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Kulkarni, Siddharth Suhas. "Design study of a horizontal axis tidal turbine blade." Thesis, Birmingham City University, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.680134.
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Tidal current power generation offers a prospect of renewable energy which is predictable, and has lower CO2 emissions than traditional energy generation sources. It also has the potential to fulfil a significant part of the energy requirements of the UK and the rest of the world. The horizontal axis tidal turbine (HATT) acts as one of the means to convert the kinetic energy available in seawater into mechanical energy, and this research explores the hydrodynamics and the Computational Fluid Analysis (CFD) based design study of this. The first aim of this research was to develop a novel HATT blade shape through bio-mimicking a curved caudal fin shape to produce improved power coefficient. A second aim was to compare two different turbulence modelling techniques to enable the comparison of the power coefficients with the standard HATT models in tidal turbine blade literature. There were two types of numerical approaches used: The SST model and a more complex mathematical model, LES-Smagorinsky, to perform steady state and transient CFD analysis respectively on the designed blades using ANSYS CFX. The initial default HATT was designed, parameterised, and represented as a straight blade following to the standard HATT literature. The airfoil centres of the straight blade are built around the centreline, where the centreline acts as the master, and a novel third order polynomial function was integrated on the centreline to model the Blue Marlin fish caudal fin look-alike target shape. This approach was used to model the further 3 sets of curved blade shapes in percentage wise chord lengths. The CFD analysis of the two dimensional airfoils was conducted using ANSYS CFX, and compared against the literature. A further comparative analysis was performed with different mesh settings, and using the SST turbulence model. The comparative analysis formed an integral part of the CFD analysis to define the boundary conditions and the verification of the three dimensional CFD based HATT design study. The design strategy to move the curved blade backwards to the straight blade was also developed. The results obtained from the three dimensional comparative CFD analysis show good agreement between the two different turbulence modelling techniques used also producing an improved curved blade shape achieving the power coefficient of 0.5073% for SST simulations and 0.5178% for the LES-Smagorinsky CFD simulations. It is seen that LES-Smagorinsky CFD results produce slightly greater efficiency than the SST simulations, but the computational overhead required is massive. Finally, after comparing the improved efficiency of the bio-mimicked curved blade with the standard HATT models in the literature, it can proved that bio-mimicking the caudal fin look-alike blade produces a higher power coefficient than the standard HATT blade.
4
Caboni, Marco. "Probabilistic design optimization of horizontal axis wind turbine rotors." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7338/.
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Considerable interest in renewable energy has increased in recent years due to the concerns raised over the environmental impact of conventional energy sources and their price volatility. In particular, wind power has enjoyed a dramatic global growth in installed capacity over the past few decades. Nowadays, the advancement of wind turbine industry represents a challenge for several engineering areas, including materials science, computer science, aerodynamics, analytical design and analysis methods, testing and monitoring, and power electronics. In particular, the technological improvement of wind turbines is currently tied to the use of advanced design methodologies, allowing the designers to develop new and more efficient design concepts. Integrating mathematical optimization techniques into the multidisciplinary design of wind turbines constitutes a promising way to enhance the profitability of these devices. In the literature, wind turbine design optimization is typically performed deterministically. Deterministic optimizations do not consider any degree of randomness affecting the inputs of the system under consideration, and result, therefore, in an unique set of outputs. However, given the stochastic nature of the wind and the uncertainties associated, for instance, with wind turbine operating conditions or geometric tolerances, deterministically optimized designs may be inefficient. Therefore, one of the ways to further improve the design of modern wind turbines is to take into account the aforementioned sources of uncertainty in the optimization process, achieving robust configurations with minimal performance sensitivity to factors causing variability. The research work presented in this thesis deals with the development of a novel integrated multidisciplinary design framework for the robust aeroservoelastic design optimization of multi-megawatt horizontal axis wind turbine (HAWT) rotors, accounting for the stochastic variability related to the input variables. The design system is based on a multidisciplinary analysis module integrating several simulations tools needed to characterize the aeroservoelastic behavior of wind turbines, and determine their economical performance by means of the levelized cost of energy (LCOE). The reported design framework is portable and modular in that any of its analysis modules can be replaced with counterparts of user-selected fidelity. The presented technology is applied to the design of a 5-MW HAWT rotor to be used at sites of wind power density class from 3 to 7, where the mean wind speed at 50 m above the ground ranges from 6.4 to 11.9 m/s. Assuming the mean wind speed to vary stochastically in such range, the rotor design is optimized by minimizing the mean and standard deviation of the LCOE. Airfoil shapes, spanwise distributions of blade chord and twist, internal structural layup and rotor speed are optimized concurrently, subject to an extensive set of structural and aeroelastic constraints. The effectiveness of the multidisciplinary and robust design framework is demonstrated by showing that the probabilistically designed turbine achieves more favorable probabilistic performance than those of the initial baseline turbine and a turbine designed deterministically.
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Ibrahim, Shewkar El-Bassiouni. "Risk-based design of horizontal curves with restricted sight distance." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/32687.
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Current geometric design guides provide deterministic standards where the safety margin of the design output is generally unknown and there is little knowledge on the safety implications of deviating from these standards. Several studies have advocated probabilistic geometric design where reliability analysis can be used to account for the uncertainty in the design parameters and to provide a risk measure of the degree of deviation from design standards. In reliability analysis, this risk is represented by the probability of non-compliance (Pnc) defined as the probability that the supply exceeds the demand. However, there is currently no link between measures of design reliability and the quantification of safety using collision frequency. The analysis presented in this thesis attempts to incorporate a reliability-based quantitative risk measure in the development of Safety Performance Functions (SPFs).
The thesis considers the design of horizontal curves, where non-compliance occurs whenever the available sight distance (ASD; supply) falls short of the stopping sight distance (SSD; demand). The inputs of SSD are random variables and appropriate probability distributions were assumed for each. A comprehensive database for the Trans-Canada Highway was used to compute the probability of non-compliance (Pnc) for 100 segments of horizontal curves. Several Negative Binomial (NB) Safety Performance Functions (SPFs) were developed and the predicted collisions were found to increase with risk (Pnc) and that the rate of increase varies by severity level. The likelihood ratio test showed that the inclusion of a risk parameter (Pnc) has generated better predictive models that have significantly outperformed the traditional models. Further, a spatial analysis was carried out which showed that the spatial models were successful in overcoming potential model misspecification resulting from incorporating only exposure and Pnc in the SPFs as relevant covariates might have been omitted.
The optimization of cross-section design to minimize the risk associated with restricted sight distance was also considered using a multiple objective function that involves new Collision Modification Factors (CMFs) incorporating Pnc. The results indicated that accounting for the random variations due to drivers’ behavior proactively at the design stage would decrease collisions in addition to achieving an overall risk reduction.
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Hassan, Yasser Carleton University Dissertation Engineering Civil. "Geometric design considerations of combined horizontal and vertical highway alignments." Ottawa, 1996.
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Tang, Xinzi. "Aerodynamic design and analysis of small horizontal axis wind turbine blades." Thesis, University of Central Lancashire, 2012. http://clok.uclan.ac.uk/7127/.
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The exploitation of small horizontal axis wind turbines provides a clean, prospective and viable option for energy supply. Although great progress has been achieved in the wind energy sector, there is still potential space to reduce the cost and improve the performance of small wind turbines. An enhanced understanding of how small wind turbines interact with the wind turns out to be essential. This work investigates the aerodynamic design and analysis of small horizontal axis wind turbine blades via the blade element momentum (BEM) based approach and the computational fluid dynamics (CFD) based approach. From this research, it is possible to draw a series of detailed guidelines on small wind turbine blade design and analysis. The research also provides a platform for further comprehensive study using these two approaches. The wake induction corrections and stall corrections of the BEM method were examined through a case study of the NREL/NASA Phase VI wind turbine. A hybrid stall correction model was proposed to analyse wind turbine power performance. The proposed model shows improvement in power prediction for the validation case, compared with the existing stall correction models. The effects of the key rotor parameters of a small wind turbine as well as the blade chord and twist angle distributions on power performance were investigated through two typical wind turbines, i.e. a fixed-pitch variable-speed (FPVS) wind turbine and a fixed-pitch fixed-speed (FPFS) wind turbine. An engineering blade design and analysis code was developed in MATLAB to accommodate aerodynamic design and analysis of the blades. The linearisation for radial profiles of blade chord and twist angle for the FPFS wind turbine blade design was discussed. Results show that, the proposed linearisation approach leads to reduced manufacturing cost and higher annual energy production (AEP), with minimal effects on the low wind speed performance. Comparative studies of mesh and turbulence models in 2D and 3D CFD modelling were conducted. The CFD predicted lift and drag coefficients of the airfoil S809 were compared with wind tunnel test data and the 3D CFD modelling method of the NREL/NASA Phase VI wind turbine were validated against measurements. Airfoil aerodynamic characterisation and wind turbine power performance as well as 3D flow details were studied. The detailed flow characteristics from the CFD modelling are quantitatively comparable to the measurements, such as blade surface pressure distribution and integrated forces and moments. It is confirmed that the CFD approach is able to provide a more detailed qualitative and quantitative analysis for wind turbine airfoils and rotors. With more advanced turbulence model and more powerful computing capability, it is prospective to improve the BEM method considering 3D flow effects.
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Hill, Sarah Louise. "The complex effects of obstructions on horizontal illuminance in interior lighting design." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360140.
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Kuwata, Yoshiaki 1978. "Real-time trajectory design for unmanned aerial vehicles using receding horizontal control." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/82777.
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Newey, Kerryn Brett. "The development of an optimised rotor software design tool to improve performance of small horizontal axis wind turbines." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1009431.
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Horizontal axis wind turbines are by far the most common and well understood forms of wind turbine. Typically a large amount of research and development has been invested in the technology of large scale wind turbines. Unfortunately, development of small machines (rotor diameter smaller than 10 metres) has not been as forthcoming. The advantages of small turbines are that they are accessible to the individual consumer and they are a very attractive project for the home builder. The disadvantage of small turbines is that due to the negative influence of economies of scale, they tend to be costly in relation to their power output and suffer from a long-term return on investment. Furthermore, trends in the wind industry have shown that smaller machines tend to be relatively simple devices that have been developed with very little research and development. As a result, small turbines can be inefficient, unreliable and expensive to maintain. In many cases rotor design is less than optimal, with very little blade refinement. This is especially critical for small rotors due to low Reynolds Number operation. Further exacerbating the problem is that the rotors are typically not well matched to the generator. In many cases the machines are not suited to the wind speed range in which they are designed to operate, reducing the financial viability due to poor performance. It is envisaged that by applying optimising techniques and automating some of the design complexities into a software design tool, more cost-effective and viable machines can be developed that will deliver improved performance and therefore become more financially viable.
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Pedescoll, Albacar Anna. "Clogging in horizontal subsurface flow constructed wetlands: mesures, design factors and prevention strategies." Doctoral thesis, Universitat Politècnica de Catalunya, 2010. http://hdl.handle.net/10803/108721.
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Constructed wetlands are alternative systems to conventional wastewater treatment for small communities
(up to 2000 PE). This is mainly due to that operation and maintenance costs are reduced.
Despite the advantages, the clogging of the bed is the most important trouble encountered by the
managers of subsurface flow wetlands treatment systems. The solids accumulation in the interstitial
spaces of the gravel over time causes the decrease of both, hydraulic conductivity and porosity.
This leads in the development of preferential paths and short-circuiting of the water through the
wetland, which converge in overland flow and contaminant removal efficiency decrease. Therefore,
clogging is the main limiting factor of the life span of a subsurface flow constructed wetland.
The strategies to reverse clogging imply important economic investments. Generally, the most
widespread option is the replacement of gravel. Hence the need to measure realibly the degree of
clogging of a system in order to identify the factors that influence this phenomenon and to search
new configurations and strategies to delay its progress, thus operations needed to reverse it.
Therefore, the aims of this thesis must contribute to establish new design criteria and operation of
horizontal subsurface flow constructed wetlands to minimize clogging processes without reducing
the contaminant removal efficiency. Then, the objectives were to compare a method to measure
hydraulic conductivity in situ, based on falling head permeameter, in order to determine the state of
clogging of wetlands and its horizontal distribution; to determine the most suitable indicator to assess
clogging in horizontal subsurface flow wetlands; to identifie new design and operation parameters
likely to cause or encourage the clogging of the filter medium; and to analyse two new configurations
in a pilot scale system in terms of contaminant removal and clogging development.
Among the different clogging indicators analysed (drenable porosity, hydraulic conductivity, accumulated
solids and effective volume from a tracer test), hydraulic conductivity seems to be the best
one. Firstly, because hydraulic conductivity provides information about the hydraulic behaviour
inside the bed, and linked appropriately with the accumulated solids (a correlation of 74.5% was
found between both indicators). Secondly, because its application in full-scale wetlands is more
straightforward than other techniques.Los humedales construidos son una alternativa al tratamiento convencional de agua residual para pequeños municipios (hasta 2000 hab-eq) ya que son fáciles de operar y mantener y tienen un coste de explotación bajo. El mayor inconveniente a que se enfrentan los explotadores de sistemas de tratamiento con humedales subsuperficiales es la colmatación del lecho. Con el tiempo, la acumulación de sólidos de diversa naturaleza en los espacios intersticiales del medio filtrante, provoca la disminución de la conductividad hidráulica y la porosidad iniciales de la grava. Esto conduce al desarrollo de caminos preferenciales y cortocircuitos en el curso del agua que convergen en la aparición de agua en superficie. A la larga, esto puede comprometer la capacidad depurativa del sistema. Por ello, la colmatación supone el factor limitante de la vida útil de un humedal construido. Las estrategias para solventar la colmatación, una vez se ha producido, son costosas y pasan por realizar inversiones no despreciables. Generalmente la opción más extendida es el cambio del material granular. De ahí la necesidad de medir, de manera fiable, en qué grado un sistema está colmatado, identificar los factores que influyen en el fenómeno e indagar en nuevas configuraciones y estrategias que permitan retrasar el avance de la colmatación y consigo, aplazar las intervenciones necesarias para devolver al sistema un estado óptimo de funcionamiento. Los objetivos de esta tesis doctoral han de contribuir a establecer nuevos criterios de diseño y operación de humedales construidos de flujo subsuperficial horizontal para minimizar, o cuanto menos retrasar, la colmatación de estos sistemas, sin mermar la eficiencia de eliminación de contaminantes del agua residual. Por ello, los objetivos son cuantificar la precisión y exactitud de un método de medición in situ de la conductividad hidráulica, basado en el permeámetro de carga variable, para la determinación del grado de colmatación de un lecho y la distribución horizontal de la misma; estudiar la idoneidad de diferentes indicadores de la colmatación de un humedal de flujo subsuperficial horizontal; evaluar la incidencia de diferentes factores de diseño y operación de humedales de flujo subsuperficial horizontal en el proceso de la colmatación; y caracterizar (en términos de eficiencia de eliminación de contaminantes y de evolución de la colmatación) dos nuevas configuraciones de humedales construidos a escala piloto.
Els aiguamolls construïts són una alternativa al tractament convencional d’aigua residual per a petits municipis (fins 2000 hab-eq) degut, principalment, a la facilitat en llur operació i manteniment y a les reduïdes despeses d’explotació. L’inconvenient més important amb què es troben els explotadors de sistemes de tractament amb aiguamolls subsuperficials és la colmatació del llit. Al llarg del temps, l’acumulació de sòlids de diversa natura en els espais intersticials de la grava, provoca la disminució de la conductivitat hidràulica i la porositat inicials. Això condueix al desenvolupament de camins preferencials i curtcircuits en el curs de l’aigua a través de l’aiguamoll, que convergeixen en l’aparició d’aigua en superfície, i que, a llarg termini pot comprometre la capacitat depurativa del sistema. Per això, la colmatació suposa el factor limitant de la vida útil d’un aiguamoll construït. Les estratègies per a fer front a la colmatació, un cop s’ha produït, passen per realitzar inversions econòmiques gens menyspreables. Generalment, l’opció més extesa és la reposició del material granular. D’aquí neix la necessitat de mesurar, de manera fiable, el grau de colmatació d’un sistema, d’identificar aquells factors que influeixen en el fenomen y qüestionar noves configuracions y estratègies que permetin retardar l’avenç de la colmatació, i per tant ajornar les intervencions necessàries per tornar al sistema a l’estat òptim de funcionament. Per tot això els objectius d’aquesta tesi doctoral han de contribuir a establir nous criteris de disseny i operació d’aiguamolls construïts de flux subsuperficial horitzontal per tal de minimitzar la colmatació d’aquests sistemes, sense minvar l’eficiència d’eliminació de contaminants de l’aigua residual. Els objectius específics són quantificar la precisió i exactitud d’un mètode de mesura in situ de la conductivitat hidràulica, basat en el permeàmetre de càrrega variable, per a la determinació de l’estat de colmatació d’un llit així com la distribució horitzontal d’aquesta; determinar l’indicador més adecuat per avaluar la colmatació d’un aiguamoll construït de flux subsuperficial horitzontal; identificar nous paràmetres de disseny y operación susceptibles de causar o afavorir la colmatación del medi filtrant; i caracteritzar (en termes d’eliminació de contaminants i d’evolució de la colmatación) dues noves configuracions d’aiguamolls construïts a escala pilot.
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Taylor, D. "The design and testing of a horizontal axis wind turbine with sailfoil blades." Thesis, Open University, 1985. http://oro.open.ac.uk/54193/.
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The work contained in this thesis covers the design, development and testing of a horizontal axis wind turbine (HAWT) with Sailfoil blades. Included is a brief history of wind turbine technology, its revival, a review of current wind energy developments and a literature survey of previous work on wind turbines with sail type blades. The Sailfoil blade consists of a framework of a leading edge D spar and a rigid trailing edge spar over which is stretched a fabric sock, forming a wing-like surface. The aerodynamic performance theories of HAWTs are described, as is the aerodynamic, structural and mechanical design of a 4 metre diameter, 3 bladed HAWT with Sailfoil blades. A wind turbine test facility was designed and developed for free air testing of wind turbines and is described. Free air tests were carried out on the Sailfoil wind turbine on the test facility to obtain power coefficient versus tip speed ratio curves and power versus wind speed curves for the wind turbine. These are presented and compared to predicted values.
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Gracie-Orr, Katie. "A blade design methodology for overspeed power regulation of horizontal axis tidal turbines." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28412.
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Employed in tidal turbines, overspeed power regulation (OSPR) can improve the structural robustness and decrease the complexity associated with active pitch methods, while removing the diffculties of operating in stalled flow. This may be a method by which the cost of tidal energy can be brought down. The aim of this research was to investigate the OSPR method, increase understanding of associated benefits and constraints, and develop a methodology for the design of suitable blades. It is identified that: the challenges to OSPR are higher rotational velocities, leading to increased voltage levels, an increased chance of cavitation on the rotor, and potentially detrimental thrust forces; these challenges may be best overcome with blade design alterations limiting the maximum rotational velocity. The blade design methodology uses a design platform to set boundary conditions, an existing blade design as the base case, and a blade element momentum theory (BEMT) tool as the modelling method. Blade root pitch setting, twist and chord length distribution are the variable parameters investigated. A set of ospr performance metrics and a design space sensitivity analysis, with whole-blade cavitation analyses and diagnostic plots of torque and angle of attack, are used to ascertain how function-based and then precise blade design alterations affect rotor performance. Tow tank tests defined base case rotor performance and verified the BEMT tool. Tests on the new blades allowed comparison to the base case test performance and to the BEMT prediction. Simulations showed that the new blade design regulated power without cavitation inception, without an increase in the thrust forces and with only a 3.6% drop in efficiency - as per the set boundary conditions and design requirements. The blade design methodology can be used to overcome challenges associated with overspeed and produce blades which give significant performance improvements for use in OSPR.
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Salomon, Jeffrey A. "Design and Testing of a Hyperbaric Horizontal Belt Filter for Fine Coal Dewatering." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33372.
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This objective of this project was to develop a new dewatering device that could produce a lower moisture content and better fine particle recovery than current technology. To meet this goal, a hyperbaric horizontal belt filter was designed and constructed over the course of 18 months. Once built, the filter was then thoroughly tested to determine operational capabilities. The test data showed that the lowest moisture content that could be achieved with a coarse feed (minus 1 mm screen-bowl centrifuge feed) was 8.8%. This value could be further reduced to 8.2% and capacity increased with the use of dewatering aids. When testing with a fine feed (minus 0.15 mm column product feed), the lowest moisture content was 35% without chemicals and 29% with chemicals. A 50/50 mixture by volume of coarse and fine feeds was artificially created and provided a moisture of 10.8%, which was reduced using reagents to 8.4%. The machine provided a very high recovery rate for all feed materials. Of the coal input, no less than 94% of it reported to the dry product. The pressure used to dewater the coal was the controlling factor for the air consumption of the unit. The data from these tests suggest that a full size production unit is feasible, although the power requirements for gas compression would be high.Master of Science
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Moradi, Dowlat Abad Mojtaba. "New approaches for performance evaluation and design of well completions in horizontal wells." Thesis, Heriot-Watt University, 2016. http://hdl.handle.net/10399/3233.
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Gwon, Tae gyun. "Structural Analyses of Wind Turbine Tower for 3 kW Horizontal Axis Wind Turbine." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/600.
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Structure analyses of a steel tower for Cal Poly's 3 kW small wind turbine is presented. First, some general design aspects of the wind turbine tower are discussed: types, heights, and some other factors that can be considered for the design of wind turbine tower. Then, Cal Poly's wind turbine tower design is presented, highlighting its main design features. Secondly, structure analysis for Cal Poly's wind turbine tower is discussed and presented. The loads that are specific to the wind turbine system and the tower are explained. The loads for the static analysis of the tower were calculated as well. The majority of the structure analysis of the tower was performed using the finite element method (FEM). Using Abaqus, commercial FEM software, both static and dynamic structural analyses were performed. A simplified finite element model that represents the wind turbine tower was created using beam, shell, and inertia elements. An ultimate load condition was applied to check the stress level of the tower in the static analysis. For the dynamic analysis, the frequency extraction was performed in order to obtain the natural frequencies and the mode shapes of the tower. Using the results, the response spectrum analysis and the transient dynamic analysis, which are based on the modal superposition method, were performed in order to see the structure's response for earthquakes that are likely to happen at the wind turbine installation site.
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Herrmann, Kai, Hannes Voigt, and Wolfgang Lehner. "Online horizontal partitioning of heterogeneous data." De Gruyter, 2014. https://tud.qucosa.de/id/qucosa%3A72923.
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In an increasing number of use cases, databases face the challenge of managing heterogeneous data. Heterogeneous data is characterized by a quickly evolving variety of entities without a common set of attributes. These entities do not show enough regularity to be captured in a traditional database schema. A common solution is to centralize the diverse entities in a universal table. Usually, this leads to a very sparse table. Although today’s techniques allow efficient storage of sparse universal tables, query efficiency is still a problem. Queries that address only a subset of attributes have to read the whole universal table includingmany irrelevant entities. Asolution is to use a partitioning of the table, which allows pruning partitions of irrelevant entities before they are touched. Creating and maintaining such a partitioning manually is very laborious or even infeasible, due to the enormous complexity. Thus an autonomous solution is desirable. In this article, we define the Online Partitioning Problem for heterogeneous data. We sketch how an optimal solution for this problem can be determined based on hypergraph partitioning. Although it leads to the optimal partitioning, the hypergraph approach is inappropriate for an implementation in a database system. We present Cinderella, an autonomous online algorithm for horizontal partitioning of heterogeneous entities in universal tables. Cinderella is designed to keep its overhead low by operating online; it incrementally assigns entities to partition while they are touched anyway duringmodifications. This enables a reasonable physical database design at runtime instead of static modeling.
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Perry, Dylan R. "AERODYNAMIC DESIGN AND STRUCTURAL ANALYSIS PROCEDURE FOR SMALL HORIZONTAL-AXIS WIND TURBINE ROTOR BLADE." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1375.
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This project accomplished two correlated goals of designing a new rotor blade to be used with the Cal Poly Wind Power Research Center, as well as defining the methodology required for the aerodynamic analysis of an optimized blade, the procedure required for generation of an accurate CAD model for the new blade geometry, and structural integrity verification procedure for the new blade via finite element analysis under several operating scenarios. The new rotor blades were designed to perform at peak efficiency at a much lower wind speed than the current CPWPRC rotor blades and incorporated a FEA verification process which was not performed on the earlier rotor blade design.
Since the wind characteristics relative to the location of the CPWPRC are essentially unchanging the most viable option, in regards to generating power for longer periods of time, is to redesign the HAWT rotor to capture more of the wind energy available. To achieve this, the swept area of the rotor was increased, suitable airfoils were utilized, and the new rotor blades were optimized to maximize their performance under the CPWPRC location’s wind conditions.
With an increased magnitude of wind energy being captured the aerodynamic loading on the rotor blades simultaneously increased which necessitated a structural analysis step to be implemented, both with classical hand calculations and with the assistance of an adequate FEA program, to ensure the new rotor blades did not fail under normal or extreme wind conditions. With the completion of this project the new rotor blade designed and analyzed in this report may be finalized and refined in order to be incorporated into the CPWPRC system in the future or the methodology defined throughout this project may be used to design an entirely different aerodynamically optimized rotor blade, including a CAD model and FEA structural integrity verification, as well.
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Almeida, MaurÃcio Soares de. "ImplementaÃÃo Computacional para Desenvolvimento de PÃs de Turbinas EÃlicas de Eixo Horizontal." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9432.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorO projeto aerodinÃmico de um rotor eÃlico visa a otimizaÃÃo dos parÃmetros de funcionamento, para que este forneÃa uma maior eficiÃncia no regime de operaÃÃo em que à utilizado. O presente trabalho consiste na criaÃÃo de um software em linguagem C++, por meio do ambiente de desenvolvimento integrado C++Builder, atravÃs de um mÃtodo clÃssico de projeto de turbinas eÃlicas baseado na Teoria do Momento do Elemento de Pà (BEM). O software fornece ao usuÃrio dados geomÃtricos de construÃÃo, como curvas de afilamento e torÃÃo da pà com base nos dados dos aerofÃlios utilizados. A anÃlise da curva de potÃncia à feita e mostrada atravÃs de um grÃfico caracterÃstico. O software prediz as alteraÃÃes de desempenho devido Ãs perdas pela ponta e pela raiz da pÃ, e tambÃm informa, entre outras coisas, a distribuiÃÃo das cargas mÃximas ao longo da mesma, de acordo com a faixa de operaÃÃo desejada pelo usuÃrio. A potÃncia fornecida pelo aerogerador pode ser calculada atravÃs de dados de velocidade dos ventos.
The aerodynamic design of a wind rotor aims to optimize the operating parameters, so that this provides a more efficient system operation in which it is used. This work consists in creating a software in C + + language through the integrated development environment C + + Builder, via a classic method of wind turbines design based on the Blade Element Momentum Theory (BEM). The software provides the user with geometric data for building, such as curved taper of the blade and torsion based on the airfoils data used. The power curve analysis is performed and displayed via a characteristic plot. The software predicts performance changes due to losses by the tip and the root of the blade, and also shows, among other things, the distribution of maximum loads along the blade, in the operating range desired by the user. The power delivered by the turbine can be calculated using wind speed data.
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Elfarra, Monier A. K. "Horizontal Axis Wind Turbine Rotor Blade: Winglet And Twist Aerodynamic Design And Optimization Using Cfd." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612987/index.pdf.
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The main purpose of this study is to aerodynamically design and optimize winglet, twist angle distribution and pitch angle for a wind turbine blade using CFD to produce more power. The RANS solver of Numeca Fine/Turbo was validated by two test cases, the NREL II and NREL VI blades. The results have shown a
considerable agreement with measurements for both cases. Two different preconditioners have been implemented for the low Mach number flow. The results have shown the superiority of Merkle preconditioner over Hakimi one and Merkle
was selected for further simulations. In addition to that, different turbulence models have been compared and the Launder &ndashSharma has shown the best agreement with measurements. Launder &ndash
Sharma was chosen for further simulations and for the design process. Before starting the design and optimization, different winglet configurations were studied. The winglets pointing towards the suction side of the blade have yielded higher power output. Genetic algorithm and artificial neural network were implemented in the design and optimization process. The optimized winglet has shown an increase in power of about 9.5 % where the optimized twist has yielded to an increase of 4%. Then the stall regulated blade has been converted into pitch regulated blade to yield more power output. The final design was produced by a combination of the optimized winglet, optimized twist andbest pitch angle for every wind speed. The final design has shown an increase in power output of about 38%.
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Santos, Claudemilson dos. "Diretrizes para a sinalização de trânsito anamórfica : uma proposta no redesenho da sinalização horizontal. /." Bauru, 2018. http://hdl.handle.net/11449/153887.
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Orientador: Galdenoro Botura JúniorBanca: José Carlos Placido da Silva
Banca: Milton Koji Nakata
Banca: Carolina Lotufo Bueno Bartholomei
Banca: Roberto Deganutti
Resumo: Esta tese consiste num estudo que visou avaliar o impacto da aplicação da anamorfose no redesenho da sinalização de trânsito horizontal, cuja hipótese supõe que pode melhorar a percepção dos motoristas para essa categoria de sinalização de trânsito. Anamorfose é o nome que se dá para o desenho em perspectiva cônica cujo plano de projeção não é perpendicular à linha de visada. O plano de projeção pode se dividir em várias superfícies e formas, a imagem projetada se distorce até ficar irreconhecível; mas quando observado do ponto de vista pré-determinado, a imagem se forma novamente. Na sinalização de trânsito horizontal a anamorfose é utilizada para simular uma aparência tridimensional aos sinais de trânsito horizontais, denominada como Sinalização Horizontal Anamórfica (SHA). A base teórica, que se fundamentou nos princípios do design ergonômico e nas teorias da percepção e do comportamento humano; está expressa numa revisão que buscou compilar e discutir a relação entre as diversas áreas do conhecimento humano e o sistema de percepção visual no trânsito, e analisando-se o problema de pesquisa de diversos pontos de vista, buscando-se concordâncias, discordâncias e avanços nas ciências que estudam o comportamento humano. Para encontrar evidências que pudessem comprovar ou refutar a hipótese, foi realizado um experimento de desenvolvimento e aplicação de uma SHA em um trecho urbano simulado e comparou-se a taxa de percepção dos motoristas que por ela passaram com os que passara... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This thesis consists of a study that aimed to evaluate the impact of the application of anamorphosis on the redesign of horizontal traffic signs, whose hypothesis supposes that it can improve the perception of the drivers for this category of traffic signaling. Anamorphosis is the name given to the conical perspective drawing whose projection plane is not perpendicular to the line of sight. The projection plane can divide into several surfaces and shapes, the projected image distorts until it is unrecognizable; but when viewed from the predetermined point of view, the image is formed again. In horizontal traffic signaling the anamorphosis is used to simulate a three-dimensional appearance to the horizontal traffic signals, denominated Horizontal Anamorphic Signaling (SHA - from potuguese "Sinalização Horizontal Anamórfica). The theoretical basis, which was based on the principles of ergonomic design and theories of human perception and behavior; is expressed in a review that sought to compile and discuss the relationship between the various areas of human knowledge and the system of visual perception in traffic, and analyzing the research problem from different points of view, seeking concordances, disagreements and advances in sciences that study human behavior. To find evidence that could prove or disprove the hypothesis, an experiment was carried out to develop and apply an SHA in a simulated urban stretch, comparing the perception rate of the drivers that passed with thos... (Complete abstract click electronic access below)
Doutor
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Flaherty, Annette E. "Support of GRP vessels : a comparative study for the horizontal support of laminate construction GRP storage vessels." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366892.
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Russo, Maria Rachel de Araujo. "O impacto de manobras de veículos combinados sobre a geometria horizontal de interseções rodoviárias." Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-09042018-111306/.
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Este estudo contribui para um melhor entendimento do desempenho de veículos combinados em interseções de rodovias secundárias. A hipótese de que as normas nacionais e estrangeiras não são adequadas para permitir a compatibilidade entre a circulação desses veículos e a geometria horizontal de interseções em nível no Brasil é investigada. Através de processo de simulação demonstramos que, com relação ao arraste, o comportamento de veículos com mais de uma articulação pode ser bom, e por vezes melhor que o de veículos com apenas uma articulação, se considerados certos aspectos operacionais e de engenharia. Contamos que as autoridades de tráfego brasileiras passem a ser menos restritivas para com a regulamentação de dimensões de veículos combinados longos, tendo em vista o aumento de produtividade alcançado com o seu uso. Como a regulamentação brasileira tem sido tradicionalmente influenciada por normas e recomendações estrangeiras, tanto para o projeto e construção de vias como para a regulamentação de veículos, procuramos caracterizar as diferenças de comportamento dos veículos e as respectivas discrepâncias em relação às normas nacionais e estrangeiras. Esta avaliação visa fornecer elementos para um julgamento mais apropriado das condições brasileiras, para que possamos elaborar nossas próprias normas, promovendo melhores condições de segurança aos usuários dos sistemas de transporte rodoviário.This study contributes to a better understanding of combination vehicle performance on secondary roadway intersections. The hypothesis that national and foreign rules are inadequate to provide compatibility of the traffic of these vehicles with the horizontal geometry of at grade intersections in Brazil is investigated. With respect to offtracking, and with due consideration to certain operational and engineering concerns, we have demonstrated, through a simulation process, that the behavior of vehicles with double articulation can be good, and at times even better than the behavior of single articulated vehicles. We expect that Brazilian roadway authorities will become Iess restrictive toward the regulation of longer combination vehicles, taking into consideration the increase in productivity achieved with their use. Since Brazilian regulatory agencies have been traditionally influenced by foreign standard rules and recommendations for highway design and construction, as well as regulation of vehicles, we have tried to characterize the differences in vehicle performance and the respective discrepancies in relation to national and foreign standards. The main objective of this evaluation is to present the elements that permit a more appropriate judgment of Brazilian conditions, so that we will be able to elaborate compatible rules and procedures, thus providing better safety conditions for users of roadway transportation systems.
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Begum, Latifa. "Natural and mixed convection in a horizontal cylindrical annulus with and without fins on inner cylinder." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112556.
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Determination of the heat transfer coefficients for natural and mixed convection in horizontal annuli is important for designing double pipe heat exchangers and for energy storage systems. In part one and two of this study, the 2D numerical solution of the laminar natural convection of water in six internally finned horizontal annuli has been obtained. The fins are attached to the external surface of the inner cylinder. Only the symmetrical half of the horizontal annulus with three equally spaced longitudinal divergent solid and porous fins are considered. The parameters of the problem are Rayleigh number, fin height, permeability and porosity of the porous fin, etc. The above parameters are suitably varied to ascertain their effects on fluid flow and heat transfer. The results show that traditional solid fins provide much higher heat transfer rates compared to the porous fins. Part three of this work deals with mixed convective heat transfer (laminar natural and forced convections) of water in a vented annulus. The forced flow conditions are imposed by providing an inlet at the top and an outlet at the bottom. For various parameters of the problem, the average and local Nusselt numbers along the inner cylinder are calculated for water for both aiding and opposing flows. The fourth part of this study deals with numerical modeling of natural convection of nanofluids in a horizontal cylindrical annulus. Simulations are carried out for Cu-water nanofluids. The results, in general, show that nanoparticles systematically decrease the natural convective heat transfer coefficient on the inner cylinder. Practical and useful correlations are provided for calculating average heat transfer rates from the inner cylinder in the form of average equivalent thermal conductivity and average Nusselt number for all of the four cases discussed above. These correlations are new and will be helpful in designing heat exchangers.
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Sagol, Ece. "Site Specific Design Optimization Of A Horizontal Axis Wind Turbine Based On Minimum Cost Of Energy." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611604/index.pdf.
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This thesis introduces a design optimization methodology that is based on minimizing the Cost of Energy (COE) of a Horizontal Axis Wind Turbine (HAWT) that is to be operated at a specific wind site. In the design methodology for the calculation of the Cost of Energy, the Annual Energy Production (AEP) model to calculate the total energy generated by a unit wind turbine throughout a year and
the total cost of that turbine are used. The AEP is calculated using the Blade Element Momentum (BEM) theory for wind turbine power and the Weibull
distribution for the wind speed characteristics of selected wind sites. For the blade profile sections, either the S809 airfoil profile for all spanwise locations is used or NREL S-series airfoil families, which have different airfoil profiles for different spanwise sections, are used,. Lift and drag coefficients of these airfoils are obtained by performing computational fluid dynamics analyses. In sample
design optimization studies, three different wind sites that have different wind speed characteristics are selected. Three scenarios are generated to present the effect of the airfoil shape as well as the turbine power. For each scenario, design optimizations of the reference wind turbines for the selected wind sites are performed the Cost of Energy and Annual Energy Production values are
compared.
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Ceyhan, Ozlem. "Aerodynamic Design And Optimization Of Horizontal Axis Wind Turbines By Using Bem Theory And Genetic Algorithm." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12610024/index.pdf.
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An aerodynamic design and optimization tool for wind turbines is developed by using both Blade Element Momentum (BEM) Theory and Genetic Algorithm. Turbine blades are optimized for the maximum power production for a given wind speed, a rotational speed, a number of blades and a blade radius. The optimization variables are taken as a fixed number of sectional airfoil profiles, chord lengths, and twist angles along the blade span. The airfoil profiles and their aerodynamic data are taken from an airfoil database for which experimental lift and drag coefficient data are available. The BEM analysis tool developed is first validated with the experimental data for low wind speeds. A 100 kW wind turbine, which is used in the validation, is then optimized. As a result of the optimization, the power production is improved by 40 to 80 percent. The optimization methodology is then employed to design a 1MW wind turbine with a 25m radius.
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Martínez, Valdivieso Daniel. "Towards a virtual platform for aerodynamic design, performance assessment and optimization of horizontal axis wind turbines." Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/405938.
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This thesis focuses on the study and improvement of the techniques involved on a virtual platform for the simulation of the Aerodynamics of Horizontal Axis Wind Turbines, with the ultimate objective of making Wind Energy more competitive.
Navier-Stokes equations govern Aerodynamics, which is an unresolved and very active field of research due to the current inability to capture the relevant the scales both in time and space for nowadays industrial-size machines (with rotors over 100 m in diameter). Therefore, there is a need to aim at a combination of engineering and scientific models. The structure of this thesis is designed in accordance to the previous fact, so there are clearly two parts or approaches within the conducted research: zero dimensional models and CFD based analysis.
For those zero-dimensional and (computationally) cheaper approach, the efforts done were the next: visualization and side improvements on the well known BEM code for pre-design purposes; designing an AeroElectric coupled algorithm to merge BEM with simple generator models that exclude details on electric circuits; designing a C++ code to study the dynamics
of wind turbines coupling different component models; implementation of energy production based algorithms to optimize blades pre-designed with BEM, given the wind resources at the real location.
CFD-based analysis are meant to be the tools to design wind turbines in the future. Nowadays and for the years to come, they are and will be under ongoing research. The efforts done to this rescpect have been the next: exploration, implementation and analysis of Non-Inertial Reference Frame, Immersed Boundary Method, Sliding Meshes. Additionally, Adaptive Mesh Refinement and Wall Model LES methods have been explored too.Esta tesis se focaliza en el estudio y mejora de las técnicas asociadas a la generación de una plataforma virtual para la simulación de la Aerodinámica presente en Aerogeneradores de eje horizontal cuyo objetivo último es hacer la energía eólica más competitiva. Las ecuaciones de Navier-Stokes gobiernan la Aerodinámica, que es un aspecto no resuelto y en constante investigación debido a la inabilidad de capturar las escalas turbulentas, temporales y espaciales, presentes en los aerogeneradores de tamaño industrial actuales (con diámetro de rotor por encima de los 100 m). Se necesitan ambas estrategias: modelos ingenieriles para su rápido diseño y también modelos más refinados al máximo nivel científico. La estructura de esta tesis responde precisamente a esta necesidad. Se han llevado a cabo dos estrategias bien diferencias: la construcción de modelos cero-dimensionales por un lado, y la estrategia de Dinámica de Fluidos Computacional (CFD) por otro. Los modelos cero-dimensionales son más asequibles y baratos desde un punto de vista computacional. Los esfuerzos realizados en este sentido son los siguientes: visualización de resultados y mejora de los conocidos modelos BEM (Blade Element Momentum) para estrategias de prediseño; diseño del algoritmo AeroElectric, que acopla los modelos BEM con la parte electrica del aerogenerador, llevando a cabo una visión simplificada que excluye un análisis de sus circuitos eléctricos; diseño de un código en C++ capaz de analizar el comportamiento dinámico de los aerogeneradores, modelizando sus diferentes componentes en base a los códigos ya expuestos; implementación del cálculo de la producción energética en base a algoritmos de optimización de la geometría de las palas, ya en función de los recursos eólicos de la zona en su localización final. El análisis a través de CFD aspira a ser la herramienta de diseño de aerogeneradores del futuro. A día de hoy e incluso por los próximos años, hay una prometedora línea de investigación al respecto. Los esfuerzos realizados en esta dirección son los siguientes: exploración, implementación y análisis de los métodos Non-Inertial Reference Frame (sistema de referencia no inercial), Immersed Boundary Method (IBM, método de la frontera submergida) y Sliding Meshes (mallas deslizantes). Además, las estrategias de Adaptive Mesh Refinement (refinamiento local adaptivo) and Wall Model LES (modelos de pared aplicados a LES) han sido explorados también. Ambos métodos (modelos ingenieriles y simulaciones detalladas) demandan fuertes estructuras de procesamiento geométrico. Lidiar con geometría es el cuello de botella y una parte crucial. De hecho, es el primer paso para el análisis posterior y su procesamiento es laborioso y muy costoso computacionalmente hablando. Así pues, la implementación de un entorno para la gestión geométrica fue desarrollado y presentado con anterioridad a dichos modelos. Los puntos principales del estudio geométrico son cuatro. El primero lidia con la gestión de la información asociada a la geometría de un perfil desde un punto de vista computacional y genérico. El segundo corresponde a la automatización del proceso de diseño de modelos CAD para palas, ya sea para el mallado o su fabricación final. El tercero responde a necesidad de IBM de disponer de una plataforma para gestionar la geometria de los diferentes componentes de un aerogenerador. Y el último punto trata sobre el desarrollo de un algorimo para computar las distancias desde cualquier punto de la malla al modelo geométrico de la pala basado en un archivo STL.
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Ke, Jiaying. "Process Design and Modeling of the Horizontal Ribbon Growth Method for Continuous Production of Silicon Wafers." Research Showcase @ CMU, 2018. http://repository.cmu.edu/dissertations/1142.
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This thesis contains theoretical development and experimental verification of the Horizontal Ribbon Growth (HRG) method for continuous silicon wafer manufacturing. In the HRG process, heat is removed through the top surface of the molten silicon pool, meanwhile, a thin silicon solid sheet is produced and extracted continuously, in this way minimizing material losses. We assessed three technical issues regarding the design and operation of the proposed process using mathematical modeling approaches: the overall process modeling, corrugated wavy interface, and front wedge formation. A Mathematical field model that governs the mass, momentum and energy balances is developed to provide a platform for alternative cooling/heating setups evaluation, as well as, various candidate process designs. The results of our study showed a relationship between the pulling velocity and the thickness of the ribbon that is qualitatively in agreement with available experimental results. A linear stability theory is used to investigate the wavy instability occurred at the wafer-melt interface. The conditions for the onset of stability were identified theoretically and numerically on the basis of diffusion-convection equations for the thermal, solutal fields coupled with the Navier-Stokes equation describing the flow field in the molten pool near the interface. The interface stability conditions of the system under different operating conditions were examined to establish the optimal range of operation. A cellular automata algorithm is coupled with finite difference scheme to study to evolution of crystallization for the system. The formation of dendrites at the crystal front, non-smooth/unstable solid-liquid interface, and sharp wedge were simulated. We demonstrate a more homogeneous segregation of impurities in the bottom portion of the resulting wafer, while an aggressive cooling rate results in an unsmooth interface formation. Two experimental pilot facilities were developed and utilized to validate theoretical findings and study the scale-up of the proposed process. In particular, an ice machine was built as a prototype to examine the feasibility of the process and test different preliminary design ideas, while a silicon pilot facility is utilized for experimenting with extracting silicon wafers continuously from the melt.
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Ozdemir, Mehmet Ozan. "Optimum Design Of Parallel, Horizontal And Laminar Forced Convection Air-cooled Rectangular Channels With Insulated Lateral Surfaces." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610710/index.pdf.
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The objective of this thesis is to predict numerically the optimal spacing between parallel heat generating boards. The isothermal boards are stacked in a fixed volume of electronic package enclosed by insulated lateral walls, and they are cooled by laminar forced convection of air with prescribed pressure drop. Fixed pressure drop assumption is an acceptable model for installations in which several parallel boards in electronic equipment receive the coolant from the same source such as a fan.
In the numerical algorithm, the equations that govern the process of forced convection for constant property incompressible flow through one rectangular channel are solved. Numerical results of the flow and temperature field in each rectangular channel yield the optimal board-to-board spacing by which maximum heat dissipation rate from the package to the air is achieved. After the results of the optimization procedure are given, the correlations for the determination of the maximum heat transfer rate from the package and optimal spacing between boards are, respectively, derived in terms of prescribed pressure difference, board length, and density and kinematic viscosity of air.
In conclusion, the obtained correlations are compared and assessed with the available two-dimensional studies in literature for infinite parallel plates. Furthermore, existing two-dimensional results are extended to a more generalized three-dimensional case at the end of the thesis.
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Park, Yong Kuk. "Analysis of Mechanical Failure Mechanisms and Methodology for Robust Design of Horizontal Pressure Die Casting Shot Sleeves /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487931512617216.
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Perini, Anerose. "Design estratégico para a mobilidade urbana sustentável por bicicleta em Porto Alegre." Universidade do Vale do Rio dos Sinos, 2015. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3820.
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Este trabalho parte da premissa de que o design pode incorporar iniciativas sustentáveis para colaborar com inovações sociais e, por inserir-se em tal eixo de pesquisa, trará a problemática da mobilidade urbana na cidade de Porto Alegre. Ao focalizar o Design Estratégico e suas contribuições para organizações que atuam no âmbito do transporte sustentável de tração humana, a presente pesquisa tem como objeto de estudo iniciativas urbanas de organizações horizontais - associações e grupos autorais - para a cidade anteriormente mencionada. Sendo assim, o recorte teórico delineia-se dentro do escopo do Design Estratégico na perspectiva da inovação social e cultural. Esta pesquisa possui caráter qualitativo e parte da abordagem exploratória, com o objetivo geral de compreender ações e práticas relacionadas às organizações horizontais que disseminam a cultura da mobilidade urbana sustentável em Porto Alegre a partir do ciclismo e da ressignificação da bicicleta no perímetro urbano central. O Design Estratégico é abordado aqui como principal viés, que levará a reflexões fundamentais sobre a sociedade contemporânea no que diz respeito à cultura da sustentabilidade. Para isso, são desenvolvidas entrevistas semiestruturadas que possibilitam, por meio da interpretação dos discursos dos respondentes, criar cenários futuros para as ações estratégicas das organizações entre 10 e 20 anos.
This study starts from the premise that design can incorporate sustainable initiatives to collaborate with social innovations, and due to its insertion in such research, will reflect the issue of urban mobility in the city of Porto Alegre. By focusing on the Strategic Design and its contributions to organizations that work in the field of human-powered sustainable transport, this research has the object of study urban initiatives of horizontal organizations - associations and authorial groups - to the city previously mentioned. Thus, the theoretical framework is outlined within the scope of the Strategic Design from the perspective of Social and Cultural Innovation. This research has qualitative character, was developed from an exploratory approach and its main goal was to understand the actions and practices related to horizontal organizations that disseminate the culture of sustainable urban mobility in Porto Alegre by cycling and the resignification of the use of bikes within its central urban area. The Strategic Design is treated here as the main bias that will lead to fundamental reflections on contemporary society with regard to the culture of sustainability. For this, semi-structured interviews are developed allowing through the interpretation of speeches of respondents, the creation of future scenarios for the strategic actions of organizations from 10 to 20 years.
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Slack-Smith, Amanda Jennifer, and not supplied. "The practical application of McCloud's horizontal 'Infinite canvas' through the design, composition and creation of an online comic." RMIT University. Computer Science and Information Technology, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070205.162540.
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This research examines the application of Scott McCloud's theory of the Infinite canvas, specifically the horizontal example outlined in Reinventing Comics (McCloud, 2000). It focuses on the useability and effectiveness of the Infinite canvas theory when applied as a practical example of a comic outcome for the Internet. This practical application of McCloud's horizontal Infinite canvas model has been achieved by creating a digital comic entitled Sad Reflections; a continuous horizontal narrative that is 20cm in height and 828cm in length and was designed to be viewed in a digital environment. This comic incorporates traditional comic techniques of gutters, time frames, line, with combining words and pictures, as outlined by McCloud (1993) in his first theoretical text Understanding Comics. These techniques are used to ensure that the project fulfilled the technical criteria used by the comic book industry to create comics. The project also incorporates McCloud's personally devised Infinite canvas techniques of trails, distance pacing, narrative subdivision, sustained rhythm and gradualism as outlined on his website. These new techniques are applied to assess their effectiveness in the creation of the horizontal Infinite canvas and ability to be integrated with traditional comic techniques. The focus of this project is to examine the strengths and weaknesses of McCloud's Infinite canvas theory when applied to the practical comic outcome of the Sad Reflections. Three key questions are used to guide this research. These questions are: 1. Does the application of traditional comic techniques affect the effectiveness of the Infinite canvas when implemented to a horizontal format? 2. Are the new Infinite canvas techniques as outlined by McCloud able to be applied to a horizontal format and what impact do these techniques have on the process? 3. Is the application of a horizontal Infinite canvas of benefit to future developers of web comics? Based on the outcomes of the above questions, this paper nominates strategies, considerations and suitable production processes for future developers of web comics.
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Wieneke, Katrin Marie [Verfasser], Josef [Akademischer Betreuer] Hegger, and Linh Cao [Akademischer Betreuer] Hoang. "Horizontal shear design of concrete interfaces in beam and slab structures / Katrin Marie Wieneke ; Josef Hegger, Linh Cao Hoang." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1211096661/34.
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Poole, Sean Nichola. "Optimisation of a mini horizontal axis wind turbine to increase energy yield during short duration wind variations." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/7036.
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The typical methodology for analytically designing a wind turbine blade is by means of blade element momentum (BEM) theory, whereby the aerofoil angle of attack is optimized to achieve a maximum lift-to-drag ratio. This research aims to show that an alternative optimisation methodology could yield better results, especially in gusty and turbulent wind conditions. This alternative method looks at increasing the aerofoil Reynolds number by increasing the aerofoil chord length. The increased Reynolds number generally increases the e_ectiveness of the aerofoil which would result in a higher or similar lift-to-drag ratio (even at the decreased angle of attacked require to maintain the turbine thrust coe_cient). The bene_t of this design is a atter power curve which causes the turbine to be less sensitive to uctuating winds. Also, the turbine has more torque at startup, allowing for operatation in lower wind speeds. This research is assumed to only be applicable to small wind turbines which operated in a low Reynolds number regime (<500 000), where Reynolds number manipulation is most advantageous.
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Ait, Mohammed Mahrez. "Etude des tuyères composites pour une conception optimale d'une hydrolienne à axe horizontal." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0002/document.
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La raréfaction des ressources fossiles non renouvelables et le dérèglement climatique font de la question énergétique un enjeu d’envergure mondiale. L’exploitation de nouvelles sources d’énergie renouvelable devient alors un objectif de première importance. L’énergie produite à partir des courants marins suscite depuis quelques années un intérêt particulier. Le concept de turbine sous-marine, appelée hydrolienne, désigne le dispositif permettant de convertir l’énergie cinétique des courants marins en énergie électrique. Ce travail de recherche traite les problématiques que pose la conception des hydroliennes à axe horizontal. Il sera mis en évidence que le monde des hélices marines présente une piste intéressante pour l’étude du comportement hydrodynamique des hydroliennes. Certains concepteurs d’hydroliennes avancent que l’ajout d’un système de carénage est favorable pour améliorer le rendement hydrodynamique. L’étude du gain hydrodynamique à encombrement constant que pourrait procurer l’ajout d’un carénage a donc été choisie comme point de départ de ce travail de recherche. Pour répondre au besoin des industriels lié à une problématique de gain de masse, les matériaux composites présentent un atout considérable en raison de leurs excellents rapports «masse/résistance» et «masse/rigidité». Une réalisation d’un carénage en matériaux composites présentant le meilleur ratio «puissance/masse» a été obtenue. Un carénage d’hydrolienne est de par sa position particulièrement confronté à des chocs. Ceci peut s’avérer très délicat car la structure composite en question est soumise à des sollicitations sévères liées à l’environnement marin. L’impact sur un carénage d’hydrolienne a été traité en détail dans ce travail de rechercheAgainst the backdrop of the increasing scarcity of non-renewable fossil resources and climate change, the energy problem has become a worldwide issue. Hence, the exploitation of new renewable energy sources becomes a worldwide goal of primary importance. The concept of the underwater turbine, called tidal current turbine, designates the device which allows the conversion of the kinetic energy produced by marine currents in electric energy. This research study examines the problems related to the design of horizontal axis tidal current turbines. The present study shows that the world of marine propellers, sometimes entirely left out by the designers of tidal current turbines, presents an interesting avenue of research with regard to the hydrodynamic behaviour of tidal current turbines. Certain designers of tidal current turbines use a duct and hold that the addition of the duct contributes to the improvement of the hydrodynamic performance. Therefore, the study of the hydrodynamic benefits of ducted turbine using a constant overall cross-section than the bare turbine was the starting point of the present research work. In order to meet the needs of the manufacturers of tidal current turbines, which is generally linked to a problem of mass gain, composite materials present a considerable asset on account of their excellent «mass/resistance» and «mass/rigidity» relations. A structural design of ducted tidal current turbines using composite materials has therefore been examined. Hence, the design of a composite duct which yields the best «power/mass» ratio has been proposed. The duct of the tidal current turbine is especially confronted by the impacts due to its particular position. The impact damage aspect has also been examined in detail in the present research study
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Hashemi, Mona, and Hadeel Hajem. "Panos Emporio, Extending the Brand." Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-16787.
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Brands have for a long time been used to identify and distinguish organizations, companies and products, it can be compared to as the soul of a company. A brand extension is a clear channel for product innovation, which can be a powerful tool to hold a competitive advantage. Product innovations can create differentiation; raise the brands characteristic-values, extend the area of use and block competitors.For 25 years, Panos Emporio has had a leading position in the swimwear industry and in spring of 2011 the company launched their first clothing collection for men and woman, and has recently launched an online store. The company is extending their brand and now that they have a new product category they are facing a challenge, which is underlying in our research question: How can Panos Emporio, a swimsuit brand, expand their brand image and identity to their new clothing line? The purpose of this report is to highlight important factors within brand extension that could be of value to Panos Emporio and other companies facing a brand extension.The report is a qualitative study using an abduction methodology where empirical findings have been studied parallel with the theories and vice versa. We have conducted interviews and observations, and have also collected quantitative data in form of a customer interview, to gain an understanding of the reality. We have chosen to examine and observe the brand Panos Emporio by asking questions regarding the company‟s organization, brand identity and image, as well as customer attitudes. The theoretical framework is underlying in our research study, with the initiation of portraying a brands meaning, importance and structure. Furthermore theories of brand extension with an emphasis on approach strategy and its advantages and disadvantages. The empirical chapter includes, information concerning the company´s brand, collections, costumer and retailers, as well as marketing strategies, which is a part of our data presentation.Out of our theoretical and empirical part we came to the conclusion that Panos Emporio should consider making the consumers more aware of the clothing collection before launching more products within a new product category, since the lack of awareness can throw a shadow over the main product and bring down the brand image which in terms affects the brand equity. Having good knowledge regarding the brands attribute, personality, purpose, identity and the relationship with consumers is more important than whether they should extend the brand or not. Companies need to focus on building their brand equity and image, towards the customers first. Authors believe that companies can take great advantages if a strong brand name and relationship is established at first.Program: Master in Fashion Management with specialisation in Fashion Marketing and Retailing
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Guzatto, Matheus Pereira. "Planejamento de redes horizontais por simulações numéricas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/169449.
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Embora o tema planejamento de redes geodésicas seja largamente investigado, especialmente a partir da segunda metade da década de 70, no âmbito nacional, poucos estudos são encontrados relativos ao planejamento de redes geodésicas, especialmente por meio de simulações numéricas. Recentemente, KLEIN (2014) propôs um método para o planejamento de redes geodésicas (denominado aqui de Método Klein – MK), solucionado por meio de tentativa e erro. Dentro desse contexto objetivo deste trabalho é propor melhorias e adaptar o MK para redes horizontais por meio de simulações numéricas, algo que ainda não é encontrado na Literatura aplicado à otimização de redes. No referido método, cada vez que a rede é reprovada em algum dos critérios considerados, necessita-se de um incremento feito com base na expertise do usuário. Neste trabalho foi desenvolvido um programa (em código aberto) para tornar o método independente de decisões por parte do usuário com o objetivo de tornar o MK viável. Enquanto o geodesista testa decisões em um espaço limitado de opções (por tentativa e erro), a proposta desenvolvida nessa pesquisa testa à exaustão todas as possibilidades do problema por simulações numéricas. Para isso, o usuário deve informar, além dos parâmetros considerados no MK, as seguintes informações: as coordenadas dos pontos de controle (suas precisões e direção(ões) do(os) azimute(es)); as coordenadas aproximadas dos pontos desconhecidos; quais observações serão usadas inicialmente; possíveis novas observações e, por fim, os equipamentos disponíveis. Foram implementadas três estratégias visando minimizar o custo na etapa de planejamento, em ordem crescente de custo, são elas: repetição das observações originalmente propostas (E1); adição de novas visadas (E2) e troca de equipamento por outro de maior precisão (E3). O programa desenvolvido foi testado em três experimentos usando dados provenientes de uma rede real implantada no entorno do campus Florianópolis do Instituto Federal de Santa Catarina e simulando o uso de três equipamentos distintos. Os resultados obtidos mostram que as adaptações tornaram o MK viável do ponto de vista prático e os objetivos propostos foram concluídos com sucesso. Entre as conclusões obtidas deve-se citar: existe uma limitação para incerteza final da rede em função do equipamento utilizado; as visadas adicionais devem ser combinadas de forma a diminuir o número de estações entre os pontos de controle e os vértices desconhecidos da rede; a melhor maneira de aumentar consideravelmente o nível de confiabilidade de uma observação é repetindo-a. Por fim, são feitas considerações sobre as limitações do método proposto: dificuldade do usuário em encontrar valores ideais para a incerteza final da rede; interface visual pouco amigável; método limitado a redes horizontais; e ausência da variável custo de maneira quantitativa na etapa de planejamento.Although the topic of geodetic network planning has been extensively investigated, especially since the second half of the 1970s, at the national level, few studies have been carried out regarding the planning of geodetic networks, especially through numerical simulations. Recently, KLEIN (2014) proposed a method for the planning of geodesic networks (here called Klein - MK Method), solved by trial and error. Within this context, the objective of this work is to propose improvements and to adapt the MK to horizontal networks through numerical simulations, something that is not yet found in Literature applied to network optimization. In Klein’s work, each time the network is disapproved in any of the considered criteria, an increment is necessary based on the user's expertise. In this work, a program (open source) was developed to make the method independent of user’s decisions with the objective of disseminating the Klein Method (MK) in the related community. While the geodesist tests decisions in a limited range of options (by trial and error), the proposal developed in this paper exhausts all possibilities of the problem by numerical simulations. For this, the user must inform, in addition to the parameters considered in the MK, the following information: coordinates control points (their precisions and direction (s) of the azimuth (s)); approximate coordinates of the unknown points; which observations will be used initially; new possible observations and, finally, the available equipments. Three strategies were implemented in order to minimize the cost of the designing step, in order of increasing cost, they are: repetition of the originally proposed observations (E1); Addition of new sights (E2) and exchange of equipment for another one of better precision (E3). The developed program was tested in three experiments using data from a real network implanted in the surroundings of Florianópolis campus of the Federal Institute of Santa Catarina and simulating the use of three different equipments. Satisfactory results were obtained and the proposed objectives were successfully completed. Among the conclusions obtained should be mentioned: there is a limitation for the final accuracy of the network according to the equipment used; additional sights must be combined in such a way to reduce the number of stations between control points and unknown vertices of the network; The best way to greatly increase the level of reliability of an observation is by repeating it. Finally, considerations are made about the limitations of the proposed method: the difficulty of the user to find ideal values for the final uncertainty of the network; Unfriendly visual interface; Method limited to horizontal networks and absence of quantitative cost analysis in the planning step.
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Leng, Yujun. "Preliminary design tools in turbomachinery| Non-uniformly spaced blade rows, multistage interaction, unsteady radial waves, and propeller horizontal-axis turbine optimization." Thesis, Purdue University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10149746.
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Turbomachinery flow fields are inherently unsteady and complex which makes the related CFD analyses computationally intensive. Physically based preliminary design tools are desirable for parametric studies early in the design stage, and to provide deep physical insight and a good starting point for the later CFD analyses. Four analytical/semi-analytical models are developed in this study: 1) a generalized flat plate cascade model for investigating the unsteady aerodynamics of a blade row with non-uniformly spaced blades; 2) a multistage interaction model for investigating rotor-stator interactions; 3) an analytical solution for quantifying the impeller wake convection and pressure wave propagating between a centrifugal compressor impeller and diffuser vane; and 4) a semi-analytical model based Lifting line theory for unified propeller and horizontal-axis turbine optimization. Each model has been thoroughly validated with existing models.
With these models, non-uniformly spaced blade rows and vane clocking are investigated in detail for their potential use as a passive control technique to reduce forced response, flutter and aeroacoustic problems in axial compressors. Parametric studies with different impeller blade numbers and back sweep angles are conducted to investigate their effect on impeller wake and pressure wave propagation. Results show that the scattered pressure waves with high circumferential wave numbers may be an important excitation source to the impeller as their amplitude grows much faster as they travel inwardly than the lower order primary pressure waves. Detailed analysis of Lifting line theory reveals the mathematical and physical equivalence of Lifting line models for propellers and horizontal-axis turbines. With a new implementation, the propeller optimization code can be used for horizontal-axis turbine optimization without any modification. The newly developed unified propeller and horizontal-axis turbine optimization code based on lifting line theory and interior point method has been shown to be a very versatile tool with the capability of hub modelling, working with non-uniform inflow and including extra user specified constraints.
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Kahya, Ali Cenk. "Analyzing The Design Of Submersible Lifted Deviated Oil Wells." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12605742/index.pdf.
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Electrical Submersible Pumping (ESP) is a well known artificial lift technique in reservoirs having high-water cut and low gas-oil ratio. It is known as an effective and economical method of producing large volumes of fluid under different well conditions. ESP equipments are capable of producing in a range of 200 b/d to 60.000 b/d. A case study was done, by designing 10 deviated or horizontal wells selected from the Y-oilfield in Western Siberia. SubPUMP software developed by IHS Energy is used for designing the ESP systems of these wells. These 10 wells will be working with variable speed drives. After selecting the available equipment from the inventory, the best running frequencies are selected for these wells. Evaluations of the designs are made from the pump performance graphs of each well. The pumps should work within their optimum efficiency ranges. These ranges can be seen from the pump performance curves. If the designs made are not within these efficiency ranges, designs should be evaluated and selecting new equipment should be should be an option. Because working outside the optimum efficiency ranges will decrease the production, shorten the runlifes of the pumps and the production will not be stable.
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Pires, Julio César Pinheiro. "Estudo de rotor para turbina eólica de eixo horizontal de pequeno porte com aplicação de modelagem e simulação virtual." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/29058.
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Este trabalho apresenta um estudo para aerogerador de pequeno porte projetado inicialmente para uso residencial. A ênfase está na modelagem e simulação virtual da estrutura das pás em compósito de fibra de vidro. A modelagem geométrica foi feita com software para desenho assistido por computador (CAD 3D). Para o projeto, foi escolhido o perfil MH110 que apresenta boa relação entre coeficiente de sustentação e coeficiente de arrasto e facilidade de fabricação. Os parâmetros como o diâmetro do rotor, a corda e a torção da pá, as relações entre velocidades e a aplicação de cargas na estrutura do material utilizado foram definidos segundo bibliografia específica, software para análise de perfil aerodinâmico e simulações pelo método dos elementos finitos. Procurou-se buscar sempre a maior eficiência, segurança e economia. O material considerado para o projeto das pás foi projetado para resistir às tensões decorrentes de operação em condições consideradas normais e para rajadas de vento. A simulação pelo método dos elementos finitos foi conduzida com ferramenta computacional e levou em conta os limites de falha do material utilizado. A geometria foi simulada sem reforço interno e apresentou baixo deslocamento quando submetida às cargas aerodinâmicas de empuxo e rotacional. Ao realizar simulação com critério de falha, foi possível determinar a espessura mais adequada para o material compósito e verificar seu comportamento de acordo com diferentes velocidades de vento.This work presents a study for small wind generator designed for residential usage. The emphasis is modeling and virtual simulation of the blade structure made in composite material (fiberglass). Geometric modeling was performed by computer aided design (CAD 3D) software. The MH110 profile was chosen for design because it presents good ratio of lift coefficient and drag coefficient, and manufacturing facility. Parameters such as rotor diameter, chord and blade twist, the relationship between the blade speeds, and the application of loads on the material used were defined according to specific bibliography, software for airfoil analysis and simulations by finite element method. It tried to always seek most efficiency, safety and economy. The material was designed to withstand the stresses arising from operation under conditions considered normal and wind gusts. The simulation by finite element method was conducted by computational tool and took into account the material failure criterion. The geometry was simulated without internal reinforcement and presented low displacement when subjected to aerodynamic loads of thrust and rotational forces. When performing simulation with the failure criterion, it was possible to determine the most appropriate thickness for the composite material and verify its behavior under different wind speeds.
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Ayat, Maher. "Pavement and alignment design of a new rural road in the province of Bologna." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6508/.
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This thesis aims to give a general view of pavement types all over the world, by showing the different characteristics of each one and its different life steps starting from construction, passing by maintenance and arriving until recycling phase. The flexible pavement took the main part of this work because it has been used in the last part of this thesis to design a project of a rural road. This project is located in the province of Bologna-Italy (‘Comune di Argelato’, 26 km in the north of Bologna), and has 5677, 81 m of length. A pavement design was made using the program BISAR 3.0 and a fatigue life study was made, also, in order to estimate the number of loads (in terms of heavy vehicles axle) to cause road’s failure .
An alignment design was made for this project and a safety study was established in order to check if the available sight distance at curves respects the safety norms or not, by comparing it to the stopping sight distance.
Different technical sheets are demonstrated and several cases are discussed in order to clarify the main design principles and underline the main hazardous cases to be avoided especially at intersection. This latter, its type’s choice depends on several factors in order to make the suitable design according to the environmental data. At this part of the road, the safety is a primordial point due to the high accident rate in this zone. For this reason, different safety aspects are discussed especially at roundabouts, signalized intersections, and also some other common intersection types.
The design and the safety norms are taken with reference to AASHTO (American Association of State Highway and Transportation Officials), ACT (Transportation Association of Canada), and also according to Italian norms (Decreto Ministeriale delle Starde).
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Randall, Matthew Martin. "A study of the influence of horizontal shear stress on the design of underground excavations, with particular reference to South Crofty Tin Mine, Cornwall." Thesis, Open University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329139.
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Li, Wen-yi, and 李文毅. "Design of horizontal water turbine." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/u796mm.
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碩士國立中山大學
機械與機電工程學系研究所
96
This thesis investigates the relations between (1) free stream velocity, blade radius as well as the number of blades, and (2) generated torque, power and efficiency in the design of a water turbine. In the study, blade element momentum theory (BEMT) is exploited to devise the shape of the horizontal water turbine. Further, a CFD package is in used to simulate the flow and pressure fields. The result shows that torque and power generated by turbine vary with such parameters as inlet velocity and blade radii. As the number of blade increases, the generated power is also on the rise but to a lessened degree.It is due to the fact that fluid can hardly flow into the cross section as the blade number increases, which brings about lower cross-section velocity. So the rotational speed should decline as a consequence to obtain the angle of attack satisfying the greatest lift-drag ratio. The largest power efficiency is thus gained.
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Janaswami, Balakrishna Venkata. "Computer aided design of horizontal gating systems." 1989. http://catalog.hathitrust.org/api/volumes/oclc/20397361.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1989.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 81-84).
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Felipe, Emmanuel Leon. "Reliability-based design for highway horizontal curves." Thesis, 1996. http://hdl.handle.net/2429/4497.
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For more than fifty years the notion of comfortable lateral acceleration has governed the
horizontal curve design procedure in North America. With new road and vehicle technology,
new methods of design have to replace the old procedures to provide consistent and safer roads
to the users. The "limit state design" concept, taken from structural engineering, has already
shown to provide a meaningful value of safety to highway design, see Navin (1990-1992).
With the cooperation of the British Columbia Ministry of Transportation and Highways,
controlled experiment and field observation were performed to develop the "limit state design"
concept for highway horizontal curves. These measurements allowed to accumulate actual
statistical information of the basic variables involved in the driving process of horizontal curves.
During the experiment, designed with a Latin Square, eight regular drivers and two expert drivers
drove four different curves at two speed levels and two pavement conditions. The response
variables from this experiment were the lateral acceleration, the speed and the level of comfort.
During the observation, in addition to the geometric characteristics of the four horizontal curves
selected on the "Sea to Sky" Highway, the speed, lateral acceleration and lateral placement of the
free moving passenger cars traveling through these curves were gathered.
The computer program RELAN was used to perform First Order Reliability Method (FORM)
analysis for passenger cars subjected to skidding by comparing the expected lateral acceleration supplied by the road to the expected lateral acceleration demanded by the vehicle-driver.
RELAN was also used to compute the reliability index P and to provide the probability of noncompliance
for existing highway horizontal curves, by comparing the expected radius supplied
by the highway to the expected radius demanded by the car/driver system. From data collected
during the empirical studies^ results show an increased probability of non-compliance with a
decrease of radius.
Using reliability-based design method, transportation engineers can adjust the design of
horizontal curves to fulfill a desirable probability of non-compliance or a desirable reliability
index (3. Designers have also a representation of the main variables involved in the process of
driving in a horizontal curve and, therefore, have a better control of their designs. With
reliability analysis, transportation engineering is provided with a highway design method which
better responds to the actual driving demand on the road, and is supported with a measure of 'safety' or non-compliance.
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Tsou, You-ren, and 鄒侑任. "A Model for Automated Highway Horizontal Alignment Design." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/95962187782092990044.
Full textAbstract:
碩士國立成功大學
土木工程學系碩博士班
96
In this research we develop a mathematical model and accompanying solution method for the highway horizontal alignment design problem. The horizontal alignment of a highway can be viewed as a piecewise linear line, smoothed at the turning points with inserted circular curves and transition curves. Our model treats the piecewise linear line and the curves in two different stages. In the first stage the model solves for a good piecewise linear line that serves as an approximate alignment. In the second stage it adjusts the solution to incorporate the difference between the piecewise linear line and the curves. The problem is decomposed into the non-linear part and linear part when solveing the piecewise linear line. The former determines the azimuths of each of the line segments, which is solved with a neighborhood search approach that is insensitive to the functional form. The latter uses a linear integer program to determine the locations of the turning points. Decomposing the problem according to each components’ mathematical property allows one to develop highly efficient algorithms separetely. Specially designed mechanism enables information to flow between the components during the solution process, which is vital for obtaining high-quality solutions. Also, curve elements require highly complicated calcualtions, which forms a major burden for models seen in the literature. To ease this computational burden, we descritize the parameter domain, enumerate all possible combinations that are allowed by the design code, and obtain simple numerical relations between the shape of the piecewise linear line and the corresponding curves by linear regression. The linear integer model then incorporates the regressional functions to correctly express the code requirements. Computational testing yields ideal results that confirm the ability of this model in speed, solution quality, and the negotiating ability when requirements are hard to fulfill simultaneously. A complete highway alignment consists horizontal and vertical alignments, as well as cross section. How to extend this model to include the two other parts is an important topic for future search. Developing a sophesticated software package is also essential for this model to be used in practice.
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Kuo, Tsai-Chin, and 郭再欽. "Design and development of the Horizontal Hydrostatic Spindle." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/272v27.
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碩士國立彰化師範大學
機電工程學系
106
The purpose of this paper is to design and develop a set of horizontal spindle for the hydraulic lathes. The main specifications include a system stiffness of 877.93 N/μm and a system flow of 4.31 L/min. Firstly, the design specification of the hydrostatic spindle is determined according to the system stiffness of a composite roller and ball lathe spindle. Secondly, a complete hydrostatic spindle design process is established. At beginning the types of oil chamber and the orifices are selected. Then, using the characteristics of the thrust and radial bearings the system stiffness of the hydrostatic spindle is obtained. Finally, the 2D machining draws of the hydrostatic spindle are finished. In this paper the effect of temperature on changes in oil properties are analyzed too. In addition, the design method is also proposed for the "unloading mechanism" in the spindle drive mechanism. These presented methods can be used as a reference for future spindle design. Keywords: hydrostatic spindle, oil chamber, orifice, unloading mechanism, oil supply system, oil cooling system.
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Lin, You Xiang, and 林祐祥. "A Horizontal Hydrostatic Rotary Bearing Design and Analysis." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/13734066137889765603.
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碩士國立清華大學
動力機械工程學系
104
This thesis studies the design process of the hydrostatic bearing, and completes a horizontal hydrostatic rotary bearing design with high performance based on a properly structural design and with self-made capillary restrictors. In theory, analyze the flow resistance of the pad and restrictors to design the pressure ratio between the source and the pocket, which conduces to design the bearing stiffness. Secondly, this study probes the function of the load capacity of the single pad and the opposed pad hydrostatic bearing, and the performance of stiffness. In addition, this work also searches the relevant literature about the computation of the stiffness and the load capacity to obtain the essential parameter which influences the bearing’s characteristics, such as the oil film thickness, the land dimension, the oil viscosity, the total flow. This work will compare and analyze the experimental results and the functions about different literatures to estimate the performance of the bearing accurately. This thesis uses the existing horizontal hydrostatic bearing to do the experiment and analyze before the design contracts out. These experimental results compare the actual performance with the theoretic performance to make discussion about the probable parameter of error and present a method to improve the performance of the horizontal hydrostatic rotary bearing. Key words: horizontal hydrostatic rotary bearing, restrictor, stiffness
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Lee, Hu Chia, and 李胡嘉. "Design of 10kW Horizontal Axis Wind Turbine Assembled Blades." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5aw6b6.
Full textAbstract:
碩士長庚大學
機械工程學系
105
The size and weight of a wind turbine blade increase with the output power of the wind turbine. The increase of blade mass represents the increase of rotor inertia that increases the cut-in wind speed and reduces the energy efficiency of the wind turbine. To reduce the mass of the blades, composit materials are often used to build hollow blades but the manpower and time are costly. In this study, the blades of a 10 kW horizontal axis wind turbine are analized and optimally designed with material mechanics, aerodynamics, and Taguchi method in order to produce hollow blades assembled by injection molding parts using fiberglass reinforced Nylon, which is suitable for mass production and effectively reduces the weight and cost. The blade has seven parts, three parts and four parts on the windward side and leeward side, respectively. To strengthen the assembly, each part on the windward side has ribs and bumps on the ribs, which are fit to the notches on the leeward side. The geometric parameters of the ribs and the bumps are optimized with Taguchi method for minimizing stress and blade tip displacement under normal operation. To evaluate the stress and blade tip displacement, ANSYS® is used with the boundary conditions of the axial and tangential forces predicted by the blade element momentum theory. The results show that the solid blade weights 36.3 kg and has a maximum stress of 28.3 MPa and a blade tip displacement of 67 mm. The opimized blade assembly weights only 14.7 kg and has a maximum stress of 80.4 MPa and a blade tip displacement of 98 mm. Even though the maximum stress of the later is more than twice that of the former, it is still less than the 122 MPa yielding strength of the material. The blade tip displacement of the optimized blade is acceptable (< 100 mm). Most important of all, the mass of the optimized blade is 60% less than that of the solid blade. If the content of the fiberglass to Nylon is reduced, the mass and the maximum stress of the blade will reduce. However, the blade tip displacement increases greatly that the blade tip may hit the mast and cause damage to the blade and mast. Therefore, the 50% content of fiberglass is recomanded.
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"COMPUTER-AIDED DESIGN OF HORIZONTAL-AXIS WIND TURBINE BLADES." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605790/index.pdf.
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