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1
Dwyer, William P. (William Patrick). "Measurement of flow boundary condition data and wing pressures in a wind tunnel test of a 45 deg swept wing." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/42182.
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2
Westin, Michelle Fernandino. "Aeroelastic modeling and experimental analysis of a flexible wing for wind tunnel flutter test." Instituto Tecnológico de Aeronáutica, 2010. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=1121.
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The objective of this work is to investigate the flutter phenomena experimentally, which will unify high aspect ratio wings design for wind tunnel flutter tests (Dowell and Tang, 2002), cheaper aeroelastic models construction and a procedure used by Sheta, Harrand, Thompson and Strganac (2002) to identify the flutter onset power spectral density versus the frequency. Initially, an experimental model developed by Dowell and Tang (2002) has been considered as a baseline model and, from this point, two new models with different wing configurations were determined, including the slender body at wing's tip, which is the idea extracted from Dowell's work, so that the torsion and bending modes are coupled (torsional moment of inertia reduction). The aeroelastic model can be divided into two parts: First, the wings structural dynamic models are computed using the finite element method implements in NASTRAN solver. sequently, ZAERO software is employed to compute the aeroelastic model. Unsteady aerodynamic loading is computed through a lifting surface interference method known as ZONA 6. The wing models defined as test beds will be constructed and tested in different wind tunnels, including open and closed tests section types. The power spectral density approach might be employed as a way to identify flutter. The output signal from an accelerometer placed in the wing structure allows, through its power spectral density computation, the identification of flutter onset condition and the corresponding undisturbed flow speed. The PSD function increase means flow energy extraction, a condition to have flutter. Experimental flutter speeds are close to the theoretically computed ones by ZAERO. From these observations, it is possible to validate the aeroelastic theoretical model in a small disturbance context. After flutter onset , the limit cycle oscillations are observed, fed by freestream energy extraction. The aeroelastic models under investigation in this research are excellent models for nonlinear aeroelastic phenomena behavior study.
3
Groenewald, Stephanus. "Development of a rotary-wing test bed for autonomous flight." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/2814.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2006.<br>This project developed a low-cost avionics system for a miniature helicopter to be used for
research in the field of autonomous flight (UAVs).
Previous work was done on a small, electrically powered helicopter with some success, but the
overall conclusion was that the vehicle was underpowered. A new vehicle, the Miniature Aircraft
X−Cell, was chosen for its ability to lift a larger payload, and previous work done with it by a
number of other institutions.
An expandable architecture was designed to allow sensors and actuators to be arbitrarily added to
the system, based on the CAN standard. A CAN sensor node was developed that could digitize
12 channels at up to 16 bit resolution and do basic filtering of the data. Onboard computing was
provided by a PC/104 based computer running Linux, with additional hardware added to
interface with the CAN bus and assist with timing.
A simulation environment for the helicopter was evaluated and shown to provide a good test bed
for the control of the helicopter. Finally, the avionics was used during piloted test-flights to
measure data and judge the performance of both the modified helicopter and the electronics itself.
4
Eger, Charles Alfred Gaitan. "Design of a Scaled Flight Test Vehicle Including Linear Aeroelastic Effects." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23088.
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A procedure for the design of a scaled aircraft using linear aeroelastic scaling is developed and demonstrated. Previous work has shown the viability in matching scaled structural frequencies and mode shapes in order to achieve consistent linear scaling of simple models. This methodology is adopted for use on a high fidelity joined-wing aircraft model. Natural frequencies and mode shapes are matched by optimizing structural ply properties and nonstructural mass. A full-scale SensorCraft concept developed by AFRL and Boeing serves as the target model, and a 1/9th span geometrically scaled remotely piloted vehicle (RPV) serves as the initial design point. The aeroelastic response of the final design is verified against the response of the full-scale model. Reasonable agreement is seen in both aeroelastic damping and frequency for a range of flight velocities, but some discrepancy remains in accurately capturing the flutter velocity.<br>Master of Science
5
Smith, Todd J. "Development, Design, Manufacture and Test of Flapping Wing Micro Aerial Vehicles." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1484659431737526.
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6
Zientarski, Lauren Ann. "Wind Tunnel Testing of a Variable Camber Compliant Wing with a Unique Dual Load Cell Test Fixture." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1448893315.
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7
Garnand-Royo, Jeffrey Samuel. "Design and Evaluation of Geometric Nonlinearities using Joined-Wing SensorCraft Flight Test Article." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23234.
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The Boeing Joined-Wing SenorCraft is a novel aircraft design that has many potential benefits, especially for surveillance missions. However, computational studies have shown the potential for nonlinear structural responses in the joined-wing configuration due to aerodynamic loading that could result in aft wing buckling. The design, construction, and flight testing of a 1/9th scale, aeroelastically tuned model of the Joined-Wing SensorCraft has been the subject of an ongoing international collaboration aimed at experimentally demonstrating the nonlinear aeroelastic response in flight. To accurately measure and capture the configuration\'s potential for structural nonlinearity, the test article must exhibit equivalent structural flexibility and be designed to meet airworthiness standards. Previous work has demonstrated airworthiness through the successful flight of a Geometrically Scaled Remotely Piloted Vehicle. The work presented in this thesis involves evaluation of an aeroelastically tuned design through ground-based experimentation. The result of these experimental investigations has led to the conclusion that a full redesign of the forward and aft wings must be completed to demonstrate sufficient geometric nonlinearity for the follow-on Aeorelastically Tuned Remotely Piloted Vehicle. This thesis also presents flight test plans for the aeroelastically tuned RPV.<br>Master of Science
8
Brooks, W. G. "The design, construction and test of a postbuckled, carbon fibre reinforced plastic wing box." Thesis, Cranfield University, 1987. http://hdl.handle.net/1826/3292.
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A postbuckled, carbon fibre reinforced plastic (CFRP)
wing box has been designed, manufactured and tested
for an aerobatic light aircraft, the Cranfield Al.
Methods of analysis have been evaluated including:
i) Non-linear finite element analysis for the
prediction o-f panel postbuckling.
ii) A simpler technique based on an effective
width method. This forms the core of a design program,
'oPTIMIST'. It predicts buckling loads, postbuckled
reduced stiffness and overall column failure of
co-cured hat stiffened panels. It then optimises the
con-Figuration of a box beam for minimum weight.
iii) The use of the effective width method allied
to a large scale, linear finite element analysis.
The work includes the development of a new method
o-F construction for composite box structures. The wing
skin sti-Ffeners and rib flanges are co-cured
together. Integral slotted Joint features are formed
in each part. The structure is then adhesively bonded
together. A full description of the manufacture o-F the
wing box is included.
The structure was also tested in a specially
designed rig. It was tested to ultimate design loads
in:
i) Positive bending to 13.33.
ii) Negative bending to -96.
iii) Pure torsion resulting from full aileron
load.
iv) Torsion with 96 bending.
The compression panels were seen to postbuckle and
recover in each load case. Results are compared with
theory, and with the original aluminium Al wing. The
structure is 257. lighter than its aluminium
counterpart.
Finally, suggestions are made for possible areas
of further research.
9
Di, Nicola Federico. "Energy harvesting from piezoelectric devices embedded in a 3D printed wing." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9705/.
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This thesis work has been carried out at Clarkson University in Potsdam NY, USA and involved the design of a low elongation wing, consisting of parts made by polylactide (PLA) using the fused deposition model (FDM) technology of Rapid Prototyping, then assembled together in a thin aluminum spar. The aim of the research is to evaluate the feasibility of collecting electrical energy by converting mechanical energy from the vibration of the wing flutter. With this aim piezoelectric stripes were glued in the inner part of the wing, as well as on the aluminum spar, as monomorphic configuration.
During the phases of the project, particular attention was given to the geometry and the materials used, in order to trigger the flutter for low flow velocity.
The CAD software SolidWorks® was used for the design of the wing and then the drawings were sent to the Clarkson machine shop in order to to produce the parts required by the wing assembly.
FEM simulations were performed, using software MSC NASTRAN/PATRAN®, to evaluate the stiffness of the whole wing as well as the natural vibration modes of the structure. These data, in a first approximation, were used to predict the flutter speed.
Finally, experimental tests in the Clarkson wind tunnel facility were carried out in order to validate the results obtained from FEM analysis. The power collected by the piezoelectrics under flutter condition was addressed by tuning the resistors downstream the electronic circuit of the piezoelectrics.
10
Aarons, Tyler David. "Development and Implementation of a Flight Test Program for a Geometrically Scaled Joined Wing SensorCraft Remotely Piloted Vehicle." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/36383.
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The development and implementation of a flight test program for an unmanned
aircraft is a multidisciplinary challenge. This thesis presents the development and
implementation of a rigorous test program for the flight test of a Geometrically
Scaled Joined Wing SensorCraft Remotely Piloted Vehicle from concept through
successful flight test. The design methodology utilized in the development of the
test program is presented, along with the extensive formal review process required
for the approval of the test plan by the Air Force Research Laboratory. The
design, development and calibration of a custom instrumentation package is also
presented along with the setup, procedure and results from all testing. Results are
presented for a wind tunnel test for air data boom calibration, propulsion system
static thrust testing, a bifilar pendulum test for experimental calculation of mass
moments of inertia, a static structural loading test for structural design validation,
a full taxi test and a successful first flight.<br>Master of Science
11
Minair, Catherine. "Les angles privilégiés, grands invariants universaux : une approche par la dynamique des fluides, l'esthétique et la physio-biologie." Valenciennes, 1987. https://ged.uphf.fr/nuxeo/site/esupversions/a2fee09c-75f7-461c-88c5-71e89bf41c12.
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Des visualisations en soufflerie jusqu'à l'éclatement ont mis en évidence des relations de filiation entre les valeurs toujours privilégiées du système inter tourbillonnaire sur des ailes delta minces et les divers paramètres en particulier l'angle d'apex. L'universalité de la notion d'angle privilégié est soulignée par des considérations architecturales telles que le nombre d'or, et picturales en même temps que par des phénomènes biologiques confirmés par la géométrie, l'arithmétique et la psychophysiologie.
12
Freisleben, Michal. "Výpočet zatížení a pevnostní kontrola křídla kluzáku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228533.
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13
Araújo, Bethânia Cristhine de. "Efeito protetor do chá verde (Camellia sinensis) contra a ação genotóxica da doxorrubicina, em células somáticas de Drosophila melanogaster." Universidade Federal de Uberlândia, 2008. https://repositorio.ufu.br/handle/123456789/15816.
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The green tea is considered a functional food with antioxidant activity, and this delays the process of old age and helps in the prevention of chronicle and degenerative diseases, such as cancer and heart affections. Of catechins, present in green tea, may is extremely important in the inactivation of free radicals, which provoke damages to the DNA molecules and to the cell membranes prevent the cytotoxicity induced by the oxidative stress in different tissues, by actuating in the process of chemoprevention. In this study two crosses, ST and HB aimed at evaluating the protective effects of green tea in three different concentrations (25, 50 e 75mg/mL), combined with the antitumor agent, doxorrubicin (DXR), of the genotoxic action; by the of wing spot test (SMART) of Drosophila melanogaster. The results obtained demonstrated that in MH descendants there was not a statistically significant increase in the frequencies of spots, in the individuals treated with green tea, in standard cross (ST) as well as in the high bioactivation cross (HB - characterized by a high constitutive level of cytochrome P450) . However we could observe a statistically significant decrease in the sum of mutant spots, in MH descendants of both crossings (ST and HB), in all concentrations of green tea associated to DXR. These results suggest that green tea does not present genotoxic effect, but presents protective affect against the mutagenic and recombinagenic action of DXR in the somatic cells of D. melanogaster, in the experimental concentrations used in this study.<br>O chá verde (CV) é considerado um alimento funcional com atividade antioxidante, que retarda o processo de envelhecimento e auxilia na prevenção de doenças crônicas e degenerativas, como o câncer e doenças cardiovasculares. As catequinas, presentes neste chá, podem inativar os radicais livres que causam danos na molécula de DNA e dessa maneira, prevenir a citotoxicidade induzida pelo estresse oxidativo, em diferentes tecidos, atuando no processo de quimioprevenção. Neste estudo dois diferentes cruzamentos, ST e HB foram utilizados para avaliar o efeito do CV em três diferentes concentrações (25, 50 e 75mg/mL) combinados com um agente tumoral, doxorrubicina (DXR), de comprovada ação genotóxica; através do teste para detecção de manchas (SMART) na asa de Drosophila melanogaster. Os resultados obtidos demonstram que para os descendentes MH não houve aumento, estatisticamente significativo, nas freqüências de manchas, nos indivíduos tratados apenas com CV, tanto no cruzamento padrão (ST) quanto no cruzamento de alta bioativação (HB - caracterizado pelo alto nível constitutivo de citocromo 450). Contudo, foi observada uma redução, estatisticamente significativa, no total de manchas mutantes, nos descendentes MH, de ambos os cruzamentos (ST e HB), em todas as concentrações do CV quando associadas com a DXR. Estes resultados sugerem que o CV não possui efeito genotóxico, e, apresenta efeito protetor contra a ação mutagênica e recombinogênica induzida pela DXR em células somáticas de D. melanogaster, nas concentrações experimentais utilizadas neste estudo.<br>Mestre em Genética e Bioquímica
14
Serediuk, Vadym. "Návrh průkazných statických pevnostních zkoušek letounu v kategorii UL." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443247.
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The diploma thesis involves the design of certification static strength tests for the newly developed aircraft of the TL-Ultralight company. At the beginning of the work, the theory of aircraft testing is generally discussed with emphasis on static strength tests. Furthermore, an analysis of the requirements of the Czech regulation UL 2 and the German LTF-UL, which represent the certification basis for this aircraft, is performed. The requirements of regulations on the construction of the aircraft (or its individual parts) and the requirements for strength tests are discussed in detail. Based on the regulation and the provided calculation protocols, individual test cases and test plans of the wing, tail surfaces, engine bed, and chassis are calculated and prepared. In the end, the calculation of the rocker system and the basic design of jigs are performed.
15
Rybka, Slavomír. "Návrh konstrukce křídla čtyřmístného jednomotorového letounu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231237.
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The content of the thesis is familiarization with the aircraft TL4000 and technical parameters wings. The work includes calculation of flight envelopes as prescribed CS 23 in three weight configurations and load calculation for all points of the envelope. The work is carried out structural design wings and its elements. The stress analysis of individual design elements wing is designed to specific parts of the reserve factor. Part of the thesis is the design and methodology for the static strength test wing that required a prescription for that category of aircraft (CS 23).
16
Mesrobian, Chris Eden. "Concept Study of a High-Speed, Vertical Take-Off and Landing Aircraft." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/35574.
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The purpose of the study was to evaluate the merits of the DiscRotor concept that combine the features of a retractable rotor system for vertical take-off and landing (VTOL) with an integral, circular wing for high-speed flight. Tests were conducted to generate basic aerodynamic characteristics of the DiscRotor in hover and in fixed-wing flight. <p>
To assess the DiscRotor during hover, small scale tests were conducted on a 3ft diameter rotor without the presence of a fuselage. A â hover rigâ was constructed capable of rotating the model rotor at speeds up to 3,500 RPM to reach tip speeds of 500fps. Thrust and torque generated by the rotating model were measured via a two-component load cell, and time averaged values were obtained for various speeds and pitch angles. It has been shown that the DiscRotor will perform well in hover. Ground Effects in hover were examined by simulating the ground with a movable, solid wall. The thrust was found to increase by 50% compared to the ground-independent case. Pressure distributions were measured on the ground and disc surfaces. Velocity measurements examined the flow field downstream of the rotor by traversing a seven hole velocity probe. A wake behind the rotor was shown to contract due to a low pressure region that develops downstream of the disc. <p>
Wind tunnel experimentation was also performed to examine the fixed wing flight of the DiscRotor. These experiments were performed in the VA Tech 6â X6â Stability Tunnel. A model of the fuselage and a circular wing was fabricated based upon an initial sizing study completed by our partners at Boeing. Forces were directly measured via a six degree of freedom load cell, or balance, for free stream velocities up to 200fps. Reynolds numbers of 2 and 0.5 million have been investigated for multiple angles of attack. Low lift-to-drag ratios were found placing high power requirements for the DiscRotor during fixed-wing flight. By traversing a seven-hole velocity probe, velocities in a 2-D grid perpendicular to the flow were measured on the model. The strengths of shed vortices from the model were calculated. A method to improve fixed-wing performance was considered where two blades were extended from the disc. An increase of 0.17 in the CL was measured due to the interaction between the disc and blades. <p>
This research utilized a wide range of experiments, with the aim of generating basic aerodynamic characteristics of the DiscRotor. A substantial amount of quantitative data was collected that could not be included in this document. Results aided in the initial designs of this aircraft for the purpose of evaluating the merit of the DiscRotor concept.<br>Master of Science
17
Gibbs, Jason. "Experimental Determination of Lift and Lift Distributions for Wings In Formation Flight." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/31301.
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Experimental methods for the investigation of trailing vortex strengths, total lift, and lift distributions for three-dimensional wings in close proximity flight were developed. With these experiments we model compound aircraft flight either docked tip-to-tip, or flying in formation. There is a distinct lack of experimental formation flight data using three-dimensional wing models for tests. The absence of fixed walls on either end of the wing permits the development of the asymmetric shedding of vortices, and the determination of the asymmetric circulation distribution induced by the proximity of the leading wing. The pair consisted of a swept NACA-0012 non-cambered wing simulating one half of a leading aircraft and a rectangular cambered NACA 63-420 wing simulating the trailing aircraft. Important aspects of the work included theoretical development, experimental setup, data acquisition and processing, and results validation. Experimentally determining the lift for formation flight, in addition to the local flow behavior for a pair of wings, can provide valuable insight for the proposition of flying actual aircraft in formation to increase mission efficiency. To eliminate the need for bulky mounting stings and direct load measurement devices that can potentially interfere with the local flowfield, a minimally invasive velocity probe method is developed. A series of experiments were performed to assist with the development of the method. Velocity and vorticity distributions obtained along a near-field plane were processed to calculate wingtip vortex strengths. Additionally, vortex position instabilities and the shedding of vorticity inboard of the wingtips were observed. To determine the circulation distributions for the trailing wing, the initial method is modified. By processing velocity information acquired in a near-field plane, both the lift and induced drag were calculated for the trailing airfoil. Comparisons are made to directly measured loads and to results reported earlier. Directly measured lift and drag coefficients were found to agree with existing literature.<br>Master of Science
18
Balevi, Birtan Taner. "Flutter Analysis And Simulated Flutter Test Of Wings." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615016/index.pdf.
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Flutter is a dynamic instability which can result in catastrophic failures of an air vehicle. Preventing flutter can be an important factor in the aircraft design, affecting the structural design. Thus, the weight and performance of the aircraft is also being affected. Understanding the role of each design factor of a wing on the onset of flutter can help designers on the flutter clearance of the aircraft. Analysis to predict flutter, ground vibration tests and flight flutter tests, which are performed to verify that the dedicated flight envelope is clear from flutter, are the most important certification processes in modern aviation.
Flight flutter testing is a very expensive process. In flight flutter tests the air vehicle is instrumentated with exciters, accelerometers and transmitters to send the test data simultaneously to the ground station to be analyzed. Since flutter is a very severe instability, which develops suddenly, the data should be followed carefully by the engineers at the ground station and feedback should be provided to the pilot urgently when needed. Low test step numbers per flight, increases the cost of flutter testing. Increasing efforts in pre-flight test processes in flutter prediction may narrow the flight flutter test steps and decrease the costs.
In this study, flutter prediction methods are investigated to aid the flutter test process. For incompressible flight conditions, some sample problems are solved using typical section model. Flutter solutions of a simple 3D wing are also performed via a coupled finite element linear aerodynamics approach using the commercial tool Nastran. 3D flutter solutions of the wing are compared with the typical section solutions to see how close can the typical section method predict flutter compared to the flutter analyis using the three dimensional wing model. A simulated flutter test method is introduced utilizing the two dimensional typical section method. It is shown that with a simple two dimensional typical section method, flutter test simulation can be performed successfully as long as the typical section model approximates the dynamic properties of the wing closely.
19
Dalley, Sam. "Wind tunnel measurements on a low rise building and comparison with full-scale." Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/886/.
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20
Hamilton, Christianne Rhea. "Design of Test Sections for a High Enthalpy Wind Tunnel." MSSTATE, 2003. http://sun.library.msstate.edu/ETD-db/theses/available/etd-04082003-114126/.
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This document describes the design of a supersonic and a subsonic test section for a high enthalpy wind tunnel. A streamline is tracked through a supersonic test section using the method of characteristics. The specifics of the design program and the design techniques are illustrated for the supersonic section. The section of the paper dealing with the subsonic nozzle has a greatly diverse nature. This section details the inlet and exhaust restrictions and construction elements for the entire low speed system. The system is currently being set up for testing with the subsonic section, and the supersonic will eventually follow.
21
Lopez, Carlos R. "Comparison of wind-driven rain test methods for residential fenestration." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0025078.
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22
Schouten, Shane Michael. "Complete CFD analysis of a Velocity XL-5 RG with flight-test verification." Texas A&M University, 2008. http://hdl.handle.net/1969.1/85894.
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The Texas A&M Flight Research Laboratory (FRL) recently received delivery of its
newest aircraft, the Velocity XL-5 RG. The Velocity can fly faster than the other aircraft
owned by the FRL and does not have a propeller in the front of the aircraft to disrupt the
air flow. These are definite advantages that make the Velocity an attractive addition to
the FRL inventory to be used in boundary-layer stability and transition control. Possible
mounting locations built into the aircraft for future projects include hard points in the
wings and roof of the fuselage. One of the drawbacks of the aircraft is that it has a
canard ahead of the main wing that could disrupt the incoming flow for a wing glove or
research requiring test pieces mounted to the hard point in the wing. Therefore, it is
necessary to understand the influence the canard and the impact of its wake on the wing
of the aircraft before any in-depth aerodynamic research could be completed on the
aircraft.
A combination of in-flight measurements of the canard wake and Computational
Fluid Dynamics (CFD) were used to provide a clear picture of the flowfield around the
aircraft. The first step of the project consisted of making a 3-D CAD model of the
aircraft. This model was then used for the CFD simulations in Fluent. 2-D, 3-D, inviscid,
and viscous simulations were preformed on the aircraft. A pressure rake was designed to
house a 5-hole probe and 18 Pitot probes that extended forward of the main wing to
measure the location and strength of the canard wake at various flight conditions. There
were five primary test points that were recorded at multiple times over the course of three flights. Once all of the data were collected from the flights, the freestream
conditions became the inputs into the final, 3-D CFD simulations on the aircraft.
The good agreement between the CFD results and the in-flight measurements
provided the necessary verification of the CFD model of the aircraft. These results can
be used in the future planning and execution of experiments involving the Velocity XL-5
RG.
23
Tourn, Cremona Silvana Cecilia. "Characterization of a New Open Jet Wind Tunnel to Optimize and Test Vertical Axis Wind Turbines." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/461079.
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Basat en el creixent interès en les tecnologies ambientals urbanes, l'estudi de turinas d'eix vertical de petita escala mostra desafiaments motivadors. En aquesta tesi, es presenten els criteris de disseny, les característiques i potencialitats d'un nou túnel de vent de secció de prova oberta. Té un àrea de sortida i la broquet del túnel de 1,5 x 1,5 m2, i es pot operar amb velocitats de sortida de 3 m / s a 17 m / s. La caracterització del flux s'ha dut a terme amb tubs pitot calibrats, anemòmetres de cassoletes i anemòmetres de fil calent. Es consideren dues configuracions diferents de l'àrea de prova, amb i sense sostre. Els mesuraments en el rang de velocitats de sortida disponibles mostren que la secció transversal, on les intensitats de velocitat i turbulència mostren un nivell acceptable d'uniformitat, té una àrea de 0,8 x 0,8 m2 i una dimensió de 2 m des de la sortida del broquet del túnel. En aquesta secció de treball, la intensitat màxima de la turbulència és del 4%. La caracterització detallada del flux realitzat indica que el túnel de vent es pot utilitzar per provar models a d'aerogeneradors de petita escala.<br>Basado en el creciente interés en las tecnologías ambientales urbanas, el estudio de turinas de eje vertical de pequeña escala muestra desafíos motivadores. En esta tesis, se presentan los criterios de diseño, las características y potencialidades de un nuevo túnel de viento de seccion de prueba abierta. Tiene un área de salida e la boquilla del túnel de 1,5 x 1,5 m2, y se puede operar con velocidades de salida de 3 m/s a 17 m/s. La caracterización del flujo se ha llevado a cabo con tubos pitot calibrados, anemómetros de cazoletas y anemómetros de hilo caliente. Se consideran dos configuraciones diferentes del área de prueba, con y sin techo. Las mediciones en el rango de velocidades de salida disponibles muestran que la sección transversal, donde las intensidades de velocidad y turbulencia muestran un nivel aceptable de uniformidad, tiene un área de 0,8 x 0,8 m2 y una dimensión de 2 m desde la salida de la boquilla del túnel. En esta sección de trabajo, la intensidad máxima de la turbulencia es del 4%. La caracterización detallada del flujo realizado indica que el túnel de viento se puede utilizar para probar modelos a de aerogeneradores de pequeña escala.<br>Based on the increasing interest in urban environmental technologies, the study of small scale vertical axis wind turbines shows motivating challenges. In this thesis, we present the design criteria, characteristics and potentials of a new open jet wind tunnel. It has a nozzle exit area of 1.5 x1.5 m2, and it can be operated with exit velocities from 3 m/s to 17 m/s. The characterization of the flow has been carried out with calibrated pitot tubes, cup anemometers, and hot wire anemometers. Two different configurations of the test area, with and without a ceiling, are considered.
Measurements in the range of available exit velocities show that the cross section, where the velocity and turbulence intensities show an acceptable level of uniformity, has an area of 0.8 x 0.8 m2 and a streamwise dimension of 2 m from the nozzle exit of the tunnel. In this working section, the maximum turbulence intensity is 4%. The detailed characterization of the flow carried out indicates that the wind tunnel can be used to test small scale models of wind turbines.
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Ying, Pei. "Aerodynamic analysis of a novel wind turbine for an omni-flow wind energy system." Thesis, University of Hertfordshire, 2016. http://hdl.handle.net/2299/17355.
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The purpose of this research is to propose a novel wind turbine for an omni-flow wind energy system and investigate its aerodynamic performance. The geometry of the novel wind turbine is based upon the impulse turbine technology which has been successful in wave energy. In this study, both numerical and experimental studies were conducted to evaluate the aerodynamic features of this wind turbine. The numerical method was validated by a comparison between numerical and experimental results over a range of tip speed ratios. Results obtained from experiments and simulations indicate that the proposed wind turbine can be employed. Additionally, on the basis of the analyses performed, this new wind turbine has the potential for having a good startup feature, which means that this wind turbine can be suitable for applications in an urban environment. As an important component, the stator of this wind turbine can increase the passing flow velocity by 20%. Meanwhile, the passing flow direction also can be optimised by the stator. Aerodynamics of the wind turbine was analysed under the non-uniform flow condition, because the flow is non-uniform inside the omni-flow wind energy system. It was found that the maximum power coefficient of such a turbine under the non-uniform flow condition is lower than that under the uniform flow condition. Due to the non-uniform flow, the blades experience different flow velocities, and as a consequence, undergo different aerodynamic loads during one operation cycle. Thus the generated torque and thrust on a blade are subjected to frequent and periodical changes. Influences of the geometrical parameters on the aerodynamic characteristics of this wind turbine were investigated. From the initial study, it was found that changes of hub-to-tip ratios, numbers of blades, aerofoils and numbers of guide vanes, can significantly affect the II power performance. Additionally, the wind turbine obtained high values of maximum torque coefficients with changing geometrical parameters.
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Taylor, Nigel John. "Adaptive wall technology for two-dimensional wind tunnel testing at high subsonic through to low supersonic speeds." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294622.
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Jones, G. O. "British wind band music." Thesis, University of Salford, 2005. http://usir.salford.ac.uk/14908/.
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I have chosen to be assessed as an interpreter and conductor of British wind band music from the earliest writings for wind band up to, and including, the present day; a period covering 220 years of original compositions of wind band music, This critical evaluation represents asummary of my work on the four required projects of the DMA course, in which I hope to demonstrate an erudite knowledge, creative imagination and maturity of interpratation in the performance of wind band repertoire.
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Cousins, Martin. "Wind Uplift Resistance of Fixed Roof Tiles : Study of Test Methods." Thesis, KTH, Byggvetenskap, 1999. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34539.
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Stammler, Matthias [Verfasser]. "Endurance test strategies for pitch bearings of wind turbines / Matthias Stammler." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2020. http://d-nb.info/1219652172/34.
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Sparks, Russell. "A novel six degree of freedom dynamic wind tunnel test facility." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492066.
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Wahlberg, Eva-Lena. "The Wine Jars Speak : A text study." Thesis, Uppsala universitet, Institutionen för arkeologi och antik historia, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-174631.
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The Wine Jars Speak: A text study. Reworked and translated from a Swedish MA thesis, Vinkärlsetiketterna berättar: En textstudie from 2008 in Egyptology, Uppsala University. This paper examines the texts written on shards from wine jars found at El-Amarna, Tutankhamun’s tomb (KV 62) and Deir el-Medina. Information concerning the administration of wine and its production, found in these texts, is examined. Wine was an important element in Egyptian society and a common iconographic motif in tombs at Thebes during New Kingdom. A survey on previous research on the subject is presented. This is followed by analysis of the different reoccurring elements found in the texts. A definition of the standard formulation of the wine jar label texts is given and the minimal level of information needed for the administration of wine production and distribution is identified. The chapter of the analysis deals with the various types of information given in the label texts, such as date, wine classification, and function. The next chapter presents the words associated with the vineyard, the names of the institutions involved in the production and use of wine, and the place names that identify where wine production took place. The following chapter deals with the titles and personal names of the officials involved in wine production. This study shows that these small texts contribute to an understanding of wine production. They also display continuity in form that bridges the turbulence of the Amarna Period. The earlier examples of these texts do not have an ideological component. It is first with the Ramesside Period, and the more intrusive inclusion of the name of the King, that some ideological intent can be identified.
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De, Beer Dalene. "The antioxidant activity of South African wines in different test systems as affected by cultivar and ageing." Thesis, Stellenbosch : University of Stellenbosch, 2002. http://hdl.handle.net/10019.1/16298.
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Thesis (M. Sc.Voedselwet.)--University of Stellenbosch, 2001.<br>ENGLISH ABSTRACT: Phenolic compounds in wine, due to their antioxidant activity, are reportedly
responsible for the health-promoting properties of wines. The effect of cultivar
and in-bottle ageing on the antioxidant activity of South African wines in
different types of antioxidant assays was, therefore, investigated.
The antioxidant activity of commercial South African red (Cabernet
Sauvignon, Ruby Cabernet, Pinotage, Shiraz, Merlot) and white (Sauvignon
blanc, Chenin blanc, Chardonnay, Colombard) cultivar wines was compared
using the 2,2’-azino-di-(3-ethylbenzothialozine-sulphonic acid) radical cation
(ABTS·+) scavenging, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·)
scavenging and microsomal lipid peroxidation (MLP) assays. The red wines
was more effective than the white wines on an “as-is” and an equal total
phenol content. The total antioxidant activity (TAAABTS and TAADPPH) of Ruby
Cabernet was the lowest of the red wines, but the antioxidant potency (APABTS
and APDPPH) of red wine phenolic fractions did not differ (P ³ 0.05). Ruby
Cabernet and Pinotage were the least effective inhibitors of MLP, while Merlot
was the most effective of the red wines. Pinotage phenolic fractions had
lower (P < 0.05) APMLP than that of other red wines. Of the white wines,
Chardonnay and Chenin blanc had the highest and lowest effectivity
respectively according to all antioxidant parameters. Ascorbic acid present in
some wines increased and decreased their TAA and % MLP inhibition
respectively. TAA and % MLP inhibition correlated well (r ³ 0.7, P < 0.001)
with total phenol content of red and white wines, as well as with flavanol
content of red wines and tartaric acid ester content of white wines. The
% MLP inhibition also correlated well with flavanol content of white wines. No
correlation (P > 0.01) was obtained between TAA or % MLP inhibition and
monomeric anthocyanin content of red wines. In the deoxyribose assay, red
wines were more pro-oxidant and exhibited lower hydroxyl radical scavenging
and metal chelating abilities than white wines.
The effect of in-bottle ageing on antioxidant activity of wines was
determined using the ABTS·+ and DPPH· scavenging assays. The TAA and
total phenol content of experimental red (Pinotage and Cabernet Sauvignon)and white (Chardonnay and Chenin blanc) cultivar wines, decreased
(P < 0.05) during 12 months of storage at 0, 15 and 30 ºC. The TAAABTS of
Cabernet Sauvignon and Chardonnay, stored at 30 ºC were lower (P < 0.05)
than at 0 ºC. The APABTS and APDPPH of most wines also decreased during
storage. The monomeric anthocyanin content of red wines decreased
(P < 0.05) rapidly at 15 and 30 ºC. The flavanol content of wines (except
Chenin blanc) increased during the first 9 months, decreasing again after 12
months, while minor changes in the flavonol and tartaric acid ester content of
both red and white wines were observed. The TAAABTS exhibited a good
correlation (r ³ 0.7, P < 0.001) with total phenol content of red and white
wines, as well as with flavonol and tartaric acid ester content of red and white
wines and flavanol content of white wines. The monomeric anthocyanin
content of red wines correlated (r = 0.50, P < 0.001) weakly with TAAABTS.
The decrease in the TAAABTS of wines could thus be mainly attributed to a
decrease in their total phenol content.<br>AFRIKAANSE OPSOMMING: Die antioksidant aktiwiteit van fenoliese komponente in wyn is waarskynlik
verantwoordelik vir die gesondheidsvoordele daarvan. Die studie het dus
gepoog om effek van kultivar en veroudering na bottelering op die
antioksidant aktiwiteit van Suid-Afrikaanse wyne te ondersoek.
Die antioksidant aktiwiteit van kommersiële Suid-Afrikaanse rooi
(Cabernet Sauvignon, Ruby Cabernet, Pinotage, Shiraz, Merlot) en wit
(Sauvignon blanc, Chenin blanc, Chardonnay, Colombard) kultivarwyne is
vergelyk deur middel van die 2,2’-azino-di-(3-etielbensotialosien-sulfoon
suur)-radikaal katioon (ABTS·+) vernietigingstoets, 2,2-difeniel-1-pikrielhidrasielradikaal
(DPPH·) vernietigingstoets en mikrosomale lipiedperoksidasietoets
(MLP). Die antioksidant aktiwiteit en die antioksidant
kragtigheid (AK) van die rooiwyne was beter as dié van witwyne in al drie
antioksidant toetse. Die totale antioksidant aktiwiteit (TAAABTS en TAADPPH)
van Ruby Cabernet was die laagste van die rooiwyne, terwyl die AKABTS en
AKDPPH van rooiwyn fenoliese fraksies nie van mekaar verskil (P ³ 0.05) het
nie. Van die rooiwyne, het Ruby Cabernet en Pinotage die laagste en Merlot
die hoogste effektiwiteit in die MLP toets getoon. Die AKMLP van Pinotage se
fenoliese fraksies was die laagste van die rooiwyne. Die witwyne,
Chardonnay en Chenin blanc, het onderskeidelik die beste en swakste
antioksidant aktiwiteit en AK van die witwyne getoon in al drie antioksidant
toetse. Askorbiensuur wat in sommige witwyne voorgekom het, het die TAA
van hierdie wyne verhoog, maar hul % MLP inhibisie verlaag. Die TAA en %
MLP inhibisie het goed gekorreleer (r ³ 0.7, P < 0.001) met die totale
fenolinhoud van rooi- en witwyne, asook die flavanolinhoud van rooiwyne en
die wynsteensuur-esterinhoud van witwyne. Die % MLP inhibisie het ook
goed gekorreleer met die flavanolinhoud van witwyne. Geen korrelasie
(P > 0.1) is waargeneem tussen antioksidant aktiwiteit van rooiwyne en hul
monomeriese antosianien-inhoud. Rooiwyn was meer pro-oksidatief in die
deoksieribose toets as witwyne, maar was die swakste hidroksieradikaalvernietigers
en metaalcheleerders.Die effek van veroudering na bottelering op die antioksidant aktiwiteit
van wyne soos bepaal met die ABTS·+ en DPPH· vernietigingstoetse, is
ondersoek. Die TAA en die totale fenolinhoud van eksperimentele rooi-
(Pinotage en Cabernet Sauvignon) en witwyne (Chardonnay en Chenin blanc)
het afgeneem (P < 0.05) tydens opberging na bottelering by 0, 15 en 30 ºC
oor 12 maande. Opberging by 30 ºC het ‘n groter vermindering (P < 0.05) in
die TAAABTS waarde vir Cabernet Sauvignon en Chardonnay veroorsaak as by
0 ºC. Die meeste wyne se APABTS en APDPPH waardes het ook verminder
(P < 0.05) na 12 maande. Drastiese vermindering (P < 0.05) in die
monomeriese antosianieninhoud van rooiwyne is opgemerk tydens opberging
by 15 en 30 ºC. Tydens die eerste 9 maande se opberging het die
flavanolinhoud van wyne toegeneem (P < 0.05) en daarna afgeneem
(P < 0.05) tot by 12 maande, terwyl flavonol- en wynsteensuuresterinhoud van
beide rooi- en witwyne min verandering ondergaan het. Die totale fenolinhoud
van rooi- en witwyne, asook die flavonol en wynsteensuur-esterinhoud van
rooi-en witwyne en die flavanolinhoud van witwyne, het goed gekorreleer
(r ³ 0.7, P < 0.001) met die TAAABTS. In teenstelling met die resultate vir
kommersiële kultivarwyne, was die TAAABTS van rooiwyne swak gekorreleer
(r = 0.5, P < 0.001) met hul monomeriese antosianieninhoud. Die afname in
TAAABTS van wyne tydens veroudering kon dus meestal toegeskryf word aan
die afname in hul totale fenolinhoud.
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Capasso, Michael Anthony. "Construction and wind tunnel test of a 1/12th scale helicopter model." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA288487.
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Hamm, Christopher Eric. "AN ASSESSMENT OF FLOW QUALITY IN AN OPEN TEST SECTION WIND TUNNEL." MSSTATE, 2009. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11022009-115210/.
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The subsonic wind tunnel facility at Mississippi State University has been converted to an open test section configuration. An experimental setup was developed which is easily configurable to allow for further research. Measurements of flow quality over select portions of the test section were made to attain a basic understanding of the performance of the new configuration. A program was developed in LabVIEW to control a 3-axis traverse and perform necessary data reduction. The traverse control program was developed to perform data acquisition using a hot-film probe to facilitate the necessary measurements. Data was gathered at two wind tunnel velocity settings over several test section locations. Results of the testing program yielded recommendations on the use of the open configuration. This paper documents the procedure and setup of the testing program to include discussion of the control/data acquisition program and a discussion of the findings and recommendations.
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Bin, Ab Wahab Abas. "The development of computer package for determining and solving pedestrian wind environmental discomfort and its wind tunnel validity test." Thesis, University of Salford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305099.
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Warsido, Workamaw Paulos. "Reducing Uncertainties in Estimation of Wind Effects on Tall Buildings Using Aerodynamic Wind Tunnel Tests." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/939.
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Tall buildings are wind-sensitive structures and could experience high wind-induced effects. Aerodynamic boundary layer wind tunnel testing has been the most commonly used method for estimating wind effects on tall buildings. Design wind effects on tall buildings are estimated through analytical processing of the data obtained from aerodynamic wind tunnel tests. Even though it is widely agreed that the data obtained from wind tunnel testing is fairly reliable the post-test analytical procedures are still argued to have remarkable uncertainties. This research work attempted to assess the uncertainties occurring at different stages of the post-test analytical procedures in detail and suggest improved techniques for reducing the uncertainties.
Results of the study showed that traditionally used simplifying approximations, particularly in the frequency domain approach, could cause significant uncertainties in estimating aerodynamic wind-induced responses. Based on identified shortcomings, a more accurate dual aerodynamic data analysis framework which works in the frequency and time domains was developed. The comprehensive analysis framework allows estimating modal, resultant and peak values of various wind-induced responses of a tall building more accurately.
Estimating design wind effects on tall buildings also requires synthesizing the wind tunnel data with local climatological data of the study site. A novel copula based approach was developed for accurately synthesizing aerodynamic and climatological data up on investigating the causes of significant uncertainties in currently used synthesizing techniques. Improvement of the new approach over the existing techniques was also illustrated with a case study on a 50 story building.
At last, a practical dynamic optimization approach was suggested for tuning structural properties of tall buildings towards attaining optimum performance against wind loads with less number of design iterations.
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Grimaldi, Guillaume. "CFD Validation of the Engine Air Intake wind tests." Thesis, KTH, Aerodynamik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180041.
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The main objective of this study carried on within the Aerodynamics department of Airbus Helicopters Marignane was to validate the Engine Air Intake tests with a CFD model of the helicopter including the whole wind tunnel building. The quantities which have been validated were aerodynamic criteria presented in the below parts. This study was done in order to improve the method and tools of the Airbus Helicopters Aerodynamic Department. The modeling has been improved during this study in order to make the computations results closer to the wind tunnel tests results.
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Brown, Kenneth Alexander. "A Study of Aerodynamics in Kevlar-Wall Test Sections." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/49383.
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This study is undertaken to characterize the aerodynamic behavior of Kevlar-wall test sections and specifically those containing two-dimensional, lifting models. The performance of the Kevlar-wall test section can be evaluated against the standard of the hard-wall test section, which in the case of the Stability Wind Tunnel (SWT) at Virginia Tech can be alternately installed or replaced by the Kevlar-wall test section. As a first step towards the evaluation of the Kevlar-wall test section aerodynamics, a validation of the hard-wall test section at the SWT is performed, in part by comparing data from NACA 0012 airfoil sections tested at the SWT with those tested at several other reliable facilities. The hard-wall test section showing good merit, back-to-back tests with three different airfoils are carried out in the SWT's hard-wall and Kevlar-wall test sections. Kevlar-wall data is corrected for wall interference with a panel method simulation that simulates the unique boundary conditions of Kevlar-wall test sections including the Kevlar porosity, wall deflection, and presence of the anechoic chambers on either side of the walls. Novel measurements of the boundary conditions are made during the Kevlar-wall tests to validate the panel method simulation. Finally, sensitivity studies on the input parameters of the panel method simulation are conducted. The work included in this study encompasses a wide range of issues related to Kevlar-wall as well as hard-wall tunnels and brings to light many details of the performance of such test sections.<br>Master of Science
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EREK, ERMAN. "k-ε turbulence modeling for a wind turbine : Comparison of RANS simulations with ECN wind turbine test site Wieringermeer (EWTW) measurements". Thesis, KTH, Kraft- och värmeteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-111532.
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In this report we discuss the use of k-ε RANS (Reynolds-averaged Navier-Stokes equations) turbulence model for wind turbine applications. This model has been implemented in the new wind turbine wake CFD code that is being developed at ECN. Simulations of the wind turbine test site EWTW are compared with measurements conducted between 2005 and 2009 and with FarmFlow, ECN's current wind turbine wake code. Based on the results the uncertainties in the current approach are highlighted and areas for possible improvement are discussed.
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Hill, Kenneth M. "Development of time-varying wind uplift test protocols for residential wood roof sheathing panels." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0041332.
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Bravo, Jimenez Ismael. "Detection and removal of wind turbine ice : Method review and a CFD simulation test." Thesis, Högskolan i Gävle, Energisystem, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-27798.
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Nowadays, the energy sector is facing a huge demand that needs to be covered. Wind energy is one of the most promising energy resources as it is free from pollution, clean and probably will arise as one of the main energy sources to prevent global warming from happening. Almost 10% of the global energy demand is coming from renewable resources. By 2050 this percentage is expected to grow to 60%. Therefore, efforts on wind turbine technology (i.e. reliability, design…) need to be coped with this growth. Currently, large wind energy projects are usually carried out in higher altitudes and cold climates. This is because almost all of the cold climates worldwide offer profitable wind power resources and great wind energy potential. Operating with wind turbines in cold climates bring interesting advantages as a result of higher air density and consequently stronger winds (wind power is around 10% higher in the Nordic regions). Not only benefits can be obtained but extreme conditions force to follow harsh conditions. Low temperatures and ice accretion present an important issue to solve as can cause several problems in fatigue loads, the balance of the rotor and aerodynamics, safety risks, turbine performance, among others. As wind energy is growing steadily on icy climates is crucial that wind turbines can be managed efficiently and harmlessly during the time they operate. The collected data for the ice detection, de-icing and anti-icing systems parts was obtained through the company Arvato Bertelsmann and is also based on scientific papers. In addition, computer simulations were performed, involving the creation of a wind tunnel under certain conditions in order to be able to carry out the simulations (1st at 0ºC, 2nd at -10ºC) with the turbine blades rotating in cold regions as a standard operation. In this project, Computational Fluids Dynamics (CFD) simulation on a 5MW wind turbine prototype with ice accretion on the blades to study how CL and CD can change, also different measures of ice detection, deicing and anti-icing systems for avoiding ice accumulation will be discussed. Simulation results showed a logical correlation as expected, increasing the drag force about 5.7% and lowering the lift force 17,5% thus worsening the turbine's efficiency.
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De, La Presilla Román. "Fretting in Wind Power Pitch Bearings: Micro-Slip Experiments and Bearing Test Rig Design." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279489.
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Wind power is the fastest-growing form of green energy production in Europe, today accounting for 15% of the total power demand with 100.000 turbines installed. This tremendous development relied on a massive technological undertaking that must be continued, and even accelerated in order to meet the European Commission’s environmental goals for 2050. Currently, more active individual control of the rotor blades, turning the blade into and out of the wind, has proven its ability to reduce structural loads on the blades and other components significantly, therefore paving the road towards strong cost reductions. To allow for such adjustment, the rotor blades are connected to the rotor hub via pitch bearings. However, these new structural load reduction control strategies force the pitch bearings into a much more demanding operation condition. More frequent positioning activity and often in the form of smaller oscillating motions, when compared to traditional pitch control. This leading to an increased risk of wear damage of the pitch bearing that could fully incapacitate the blade control. At which point the safe regulation of the turbine can no longer be guaranteed and catastrophic failure, such as the loss of a rotor blade, is possible. This project pertains to the design a bearing test rig that can be used to test rolling element bearings with contact conditions that emulate those found in pitch bearings. A novel frameless motor-driven concept is proposed. The concept is aimed towards preventing unnecessary damage of non-test bearings and improving the dynamic performance of the test rig for a given motor capacity. One further objective of the project involved using an existing KTH single contact test rig to study the friction behavior of different lubricants when minute reciprocal tangential displacements are imposed.<br>Vindkraft är idag det snabbast växande området för grön elproduktion i Europa och står med 100 000 installerade turbiner för 15% av den totala elförsörjningen. Denna otroliga utvecklingen har berott på en massiv teknologisk insats som måste fortsätta. För att nå Europakommissionens miljömål för 2050 måste expansionen av grön elproduktion och vindkraft till och med trappas upp. Nyligen har en mer aktiv individuell reglering av rotorbladen, vilket möjliggör att bladen kan styras in- och ut ur vinden, visat sig kunna reducera lasterna på blad och andra komponenter avsevärt, vilket därmed möjliggör stora kostnadsreduceringar. Dessa justeringar möjliggörs genom att rotorbladen ansluter hubben via ett rotorbladslager. Dessa nya lastreducerande reglerstrategier tvingar dock lagren att arbeta under högre belastning jämfört med traditionell reglering av rotorbladens lutningsvinkel. Det här sker genom mer frekvent positionering och ofta som små oscillerande rörelser, vilket leder till en högre risk för slitage på rotorbladslagren, som i sin tur kan leda till förlust av rotorbladsregleringen. När så sker kan inte längre en säker reglering av turbinen garanteras och katastrofala fel är möjliga, så som förlust av rotorblad. Det här projektet avser att utarbeta en design för en lagerprovningsrigg som kan användas för att testa rullager med kontaktvillkor som efterliknar de som återfinns i rotorbladslagren. Ett nytt koncept,m som är baserat på en ramlös motor, presenteras. Konceptet avser att förhindra onödigt slitage hos testriggens motorlager och förbättra de dynamiska egenskaperna för en given motorkapacitet. Projektet innefattar även en studie av friktionsbeteendet hos olika smörjmedel under små upprepande tangentiella rörelser, som utförts med en befintlig testrigg på KTH.
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Bürkner, Falko [Verfasser]. "Biaxial Dynamic Fatigue Tests of Wind Turbine Blades / Falko Bürkner." Hannover : Gottfried Wilhelm Leibniz Universität, 2020. http://d-nb.info/1233426494/34.
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Panzone, Luca Alfonso. "A Test for Asymmetric Information in Food Markets : A Case Study on the Wine Sector." Thesis, University of Reading, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525127.
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Broughton, Cabot A. Carleton University Dissertation Engineering Aeronautical. "Experimental investigation of slotted wall wind tunnel test sections for low interference road vehicle testing." Ottawa, 1990.
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Lines, Philipp A. "Upgrade of a LabVIEW based data acquisition system for wind tunnel test of a 1/10 scale OH-6A helicopter fuselage." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FLines.pdf.
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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, June 2003.<br>Thesis advisor(s): E. Roberts Wood, Richard M. Howard. Includes bibliographical references (p. 53-54). Also available online.
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Baldassarre, Alessandro. "FEM and experimental analysis of a wind turbine blade." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8533/.
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This paperwork compares the a numerical validation of the finite element model (FEM) with respect the experimental tests of a new generation wind turbine blade designed by TPI Composites Inc. called BSDS (Blade System Design Study). The research is focused on the analysis by finite element (FE) of the BSDS blade and its comparison with respect the experimental data from static and dynamic investigations. The goal of the research is to create a general procedure which is based on a finite element model and will be used to create an accurate digital copy for any kind of blade. The blade prototype was created in SolidWorks and the blade of Sandia National Laboratories Blade System Design Study was accurately reproduced. At a later stage the SolidWorks model was imported in Ansys Mechanical APDL where the shell geometry was created and modal, static and fatigue analysis were carried out. The outcomes of the FEM analysis were compared with the real test on the BSDS blade at Clarkson University laboratory carried out by a new procedures called Blade Test Facility that includes different methods for both the static and dynamic test of the wind turbine blade. The outcomes from the FEM analysis reproduce the real behavior of the blade subjected to static loads in a very satisfying way. A most detailed study about the material properties could improve the accuracy of the analysis.
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Scharnberg, Fábio Augusto. "Caracterização aerodinâmcia de edifícios através do espectro das cargas totais medidas em túnel de vento." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/181819.
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Nos últimos anos cresceu o interesse por construir edifícios cada vez mais altos, os quais estampam o poderio tecnológico e econômico das nações. Concomitantemente as estruturas se tornaram mais esbeltas e flexíveis e os fenômenos dinâmicos oriundos da ação do vento, que em edificações baixas não representam grande relevância no carregamento, começam a surgir e apresentar seus efeitos. Desta maneira, é importante conhecer como se desenvolve o escoamento do ar e a distribuição das pressões no entorno destas estruturas. Neste trabalho, caracteriza-se aerodinamicamente, através de dados oriundos de ensaios em túnel de vento, dois empreendimentos reais e presentes na engenharia nacional. Os carregamentos foram gerados através da integração simultânea de pressões e transformados em espectros de força, os quais auxiliam na visualização da energia cinética contida nas rajadas, na ocorrência de desprendimento cadenciado de vórtices, martelamento e na influência que as edificações vizinhas apresentam no escoamento. A análise é realizada local e globalmente, possibilitando verificar em que “zona”, ou faixa de altura, é mais significante para o carregamento da estrutura como um todo. O fenômeno de desprendimento de vórtices é caracterizado por um pico no espectro transversal à incidência do vento. Quando existem edificações ou obstáculos na região a barlavento, a estrutura pode ser martelada até a altura média destes obstáculos. Por fim, os resultados aqui apresentados podem servir de auxílio no pré-dimensionamento de estruturas com configurações similares, como comparativo e validação para pesquisas futuras e como referencial na elaboração de códigos normativos referentes ao tema. Destaca-se a importância de ensaios em túnel de vento, principalmente quando a estrutura a ser analisada possui um detalhamento arquitetônico complexo. Estes ensaios permitem ao projetista simular todos os casos de carregamento e os efeitos de vizinhança com maior confiabilidade e precisão em relação a métodos simplificados contidos, atualmente, em códigos e normas.<br>In recent years many high-rise buildings have been built, which are a way to represent the economic and technological power of nations. Concomitantly, the structures have become slender and more flexible, and the dynamic phenomena of wind, which in low buildings do not represent a great relevance in the loading, start to show their effects. In this way, it is extremely important to know how the wind flow and the pressure distribution occur around these structures. In this research, two real projects, present in the national engineering, are characterized aerodynamically through data from wind tunnel tests. The loadings were processed through the simultaneous integration of pressures and transformed into force spectra, which aid in the visualization of the kinetic energy contained in the bursts, in the occurrence of vortex shedding, buffeting and the influence of the neighboring buildings on the wind flow. The analysis is performed locally and globally, making it possible to verify which "zone", or height range, is more significant to the loading of the structure as a whole. It can be seen that the phenomenon of vortex shedding is characterized by a peak in the crosswind spectrum and the buffeting phenomenon appears when there are buildings or obstacles in the windward region. Finally, the results presented here can be helpful in the pre-design of structures with similar configurations, in the comparison and validation for future researches and as a reference in the review of normative codes. Emphasis is given to the importance of wind tunnel testing, which allows the designer to simulate all loading cases and neighborhood effects with greater precision compared to simplified methods currently contained in codes and standards.
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Sidelko, Stephanie. "Benchmark of aerodynamic cycling helmets using a refined wind tunnel test protocol for helmet drag research." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40486.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.<br>Includes bibliographical references (leaf 30).<br>The study of aerodynamics is very important in the world of cycling. Wind tunnel research is conducted on most of the equipment that is used by a rider and is a critical factor in the advancement of the sport. However, to date, a comprehensive study of time-trial helmets has not been performed. This thesis presents aerodynamic data for the most commonly used time-trial helmets in professional cycling. The helmets were tested at a sweep of yaw angles, from 0⁰ to 15⁰, in increments of 5⁰. The helmets were tested at three head angle positions at each yaw angle in order to best mimic actual riding conditions. A control road helmet was used to serve as a comparative tool. In order to maintain manufacturer confidentiality, the helmets were all randomly assigned variables. Thus, the thesis presents ranges of benefit and drag numbers, but does not rank by helmet name. The testing results showed that aerodynamic helmets offer drag reduction over a standard road helmet. The best and the worst performing helmets are all more aerodynamic than a road helmet.<br>by Stephanie Sidelko.<br>S.B.
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Ehrmann, Robert S. "Development of Measurement Methods for Application to a Wind Tunnel Test of an Advanced Transport Model." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/369.
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California Polytechnic State University, San Luis Obispo is currently working towards developing a Computational Fluid Dynamics (CFD) database for future code validation efforts. Cal Poly will complete a wind tunnel test on the Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA) in the National Full-Scale Aerodynamics Complex (NFAC) 40 foot by 80 foot wind tunnel at NASA Ames Research Center in the summer of 2011. The development of two measurement techniques is discussed in this work, both with the objective of making measurements on AMELIA for CFD validation.
First, the work on the application of the Fringe-Imaging Skin Friction (FISF) technique to AMELIA is discussed. The FISF technique measures the skin friction magnitude and direction by applying oil droplets on a surface, exposing them to flow, measuring their thickness, and correlating their thickness to the local skin friction. The technique has the unique ability to obtain global skin friction measurements. A two foot, nickel plated, blended wing section test article has been manufactured specifically for FISF. The model is illuminated with mercury vapor lamps and imaged with a Canon 50D with a 546 nm bandpass filter. Various tests are applied to the wing in order to further characterize uncertainties related with the FISF technique. Human repeatability has uncertainties of ±2.3% of fringe spacing and ±2.0° in skin friction vector direction, while image post processing yields ±25% variation in skin friction coefficient. A method for measuring photogrammetry uncertainty is developed. The effect of filter variation and test repeatability was found to be negligible. A validation against a Preston tube was found to have 1.8% accuracy.
Second, the validation of a micro flow measurement device is investigated. Anemometers have always had limited capability in making near wall measurements, driving the design of new devices capable of measurements with increased wall proximity. Utilizing a thermocouple boundary layer rake, wall measurements within 0.0025 inches of the surface have been made. A Cross Correlation Rake (CCR) has the advantage of not requiring calibration but obtaining the same proximity and resolution as the thermocouple boundary layer rake. The flow device utilizes time of flight measurements computed via cross correlation to calculate wall velocity profiles. The CCR was designed to be applied to AMELIA to measure flow velocities above a flap in a transonic flow regime. The validation of the CCR was unsuccessful. Due to the fragile construction of the CCR, only one data point at 0.10589 inches from the surface was available for validation. The subsonic wind tunnel’s variable frequency drive generated noise which could not be filtered or shielded, requiring the use of a flow bench for validation testing. Since velocity measurements could not be made in the flow bench, a comparison of a fast and slow velocity was made. The CCR was not able to detect the difference between the two flow velocities. Currently, the CCR cannot be applied on AMELIA due to the unsuccessfully validation of the device.
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You-ChengOuyang and 歐陽佑丞. "Design and Wind-Tunneling Test Preparation of a Self-Learning Flapping-Wing Platform." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/05382694917480496606.
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碩士<br>國立成功大學<br>航空太空工程學系碩博士班<br>98<br>The usual manner of research into flight performances of an ornithopter is to offer a default flapping-wing path in prior. To achieve a better flapping efficiency and flight performance, we use an artificial intelligence-genetic algorithm in this thesis to find the optimal flapping-wing path under various wind speeds.
Recently, most researchers focus on materials, structures and mechanical platforms of flapping-wings. As to stability control, there is few study inspection of optimizing the flapping-wing path intelligently so far. In this thesis, the genetic algorithm will be adopted to search an optimal path for the flapping wing. As an artificial intelligence, the genetic algorithm is adequate to the evolutionary optimization path issue. It can record cyclic paths, and evolve them into an optimized path via the energy consumption minimization and thrust and lift maximization rather than manual adjustments on principle of the nature law. Moreover, the self-learning flapping wing makes ornithopter become a genuine biomimetic with the greatest robust flight ability in various wind conditions. These features make our ornithopter become a precursor in the field of the flapping-wind flight.
We take advantage of the artificial intelligence to facilitate the design of an ornithopter. Designing a flapping-wing aircraft with better flight performances, higher mobility and larger capacity can be acquired if one takes the experiences given by this thesis into account.