Academic literature on the topic 'Wave Rotor Analysis Codes'
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Journal articles on the topic "Wave Rotor Analysis Codes"
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Al-Rawashdeh, Ayman Y., Ali Dalabeeh, Abdallah Al-Zeyod, Ashraf Samarah, Ghazi Qaryouti, and Omar Albarbarawi. "The tooth factor effect on the harmonics of large electrical machines." Bulletin of Electrical Engineering and Informatics 9, no. 4 (2020): 1677–84. http://dx.doi.org/10.11591/eei.v9i4.1565.
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In the current study, the general mathematical model for the calculation and analysis of asynchronous systems and transient cases in asynchronous synchronous large electrical machines was developed. The theory of magnetic fields in the teeth's circuits with a smooth surface of the rotor was used and at the same time, high harmonics of magnetic fields and its effect on the transient cases was also calculated. Performance curves were investigated using Matlab codes and evaluated under different values of factor. The results confirmed the possibility of improving the noise harmonics on the sinusoidal wave form, which is reflected on the machines starting.
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Świrydczuk, Jerzy. "Wake-blade interaction in steam turbine stages." Polish Maritime Research 20, no. 2 (2013): 30–40. http://dx.doi.org/10.2478/pomr-2013-0014.
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Abstract The article discusses the phenomenon of stator Wake/Rotor cascade (W/R) interaction in a steam turbine stage, and the ability to capture it in turbine stage design calculations making use of standard numerical codes. Firstly, the W/R interaction is analysed by comparing its real, experimentally recorded course with the numerical results obtained using vortex theory models and methods. This part of the analysis ends with formulating a conclusion about stochastic nature of the W/R interaction and indicating its reason, which is the vortex structure of the stator wake. Next, a question is discussed whether and how this stochastic nature of the examined phenomenon can be taken into account in calculations of Reynolds Averaged Navier-Stokes (RANS) equations. Differences are indicated between the uniform pattern of the stator wake obtained using a RANS code and the vortex structure of the real wake. It is concluded, however, that despite these differences the RANS results correctly reflect the time-averaged course of the real W/R interaction, and the process of averaging the flow parameters on the sliding plane between stator and rotor calculation areas can be treated as sort of “numerical averaging” of different realisations of the W/R interaction.
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Boorsma, Koen, Florian Wenz, Koert Lindenburg, Mansoor Aman, and Menno Kloosterman. "Validation and accommodation of vortex wake codes for wind turbine design load calculations." Wind Energy Science 5, no. 2 (2020): 699–719. http://dx.doi.org/10.5194/wes-5-699-2020.
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Abstract. The computational effort for wind turbine design load calculations is more extreme than it is for other applications (e.g., aerospace), which necessitates the use of efficient but low-fidelity models. Traditionally the blade element momentum (BEM) method is used to resolve the rotor aerodynamic loads for this purpose, as this method is fast and robust. With the current trend of increasing rotor size, and consequently large and flexible blades, a need has risen for a more accurate prediction of rotor aerodynamics. Previous work has demonstrated large improvement potential in terms of fatigue load predictions using vortex wake models together with a manageable penalty in computational effort. The present publication has contributed towards making vortex wake models ready for application to certification load calculations. The observed reduction in flapwise blade root moment fatigue loading using vortex wake models instead of the blade element momentum (BEM) method from previous publications has been verified using computational fluid dynamics (CFD) simulations. A validation effort against a long-term field measurement campaign featuring 2.5 MW turbines has also confirmed the improved prediction of unsteady load characteristics by vortex wake models against BEM-based models in terms of fatigue loading. New light has been shed on the cause for the observed differences and several model improvements have been developed, both to reduce the computational effort of vortex wake simulations and to make BEM models more accurate. Scoping analyses for an entire fatigue load set have revealed the overall fatigue reduction may be up to 5 % for the AVATAR 10 MW rotor using a vortex wake rather than a BEM-based code.
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Nalim, M. R., and E. L. Resler. "Wave Cycle Design for Wave Rotor Gas Turbine Engines With Low NOx Emissions." Journal of Engineering for Gas Turbines and Power 118, no. 3 (1996): 474–80. http://dx.doi.org/10.1115/1.2816670.
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The wave rotor is a promising means of pressure-gain for gas turbine engines. This paper examines novel wave rotor topping cycles that incorporate low-NOx combustion strategies. This approach combines two-stage “rich-quench-lean” (RQL) combustion with intermediate expansion in the wave rotor to extract energy and reduce the peak stoichiometric temperature substantially. The thermodynamic cycle is a type of reheat cycle, with the rich-zone air undergoing a high-pressure stage. Rich-stage combustion could occur external to or within the wave rotor. An approximate analytical design method and CFD/combustion codes are used to develop and simulate wave rotor flow cycles. Engine cycles designed with a bypass turbine and external combustion demonstrate a performance enhancement equivalent to a 200–400 R (110–220 K) increase in turbine inlet temperature. The stoichiometric combustion temperature is reduced by 300–450 R (170–250 K) relative to an equivalent simple cycle, implying substantially reduced NOx formation.
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Manke, Joseph W., Joel E. Hirsh, Byung K. Oh, Thomas M. Wicks, and Leo Dadone. "Improved rotor tip-relief modeling by coupling comprehensive rotor analysis and rotor aerodynamics codes." Advances in Engineering Software 29, no. 3-6 (1998): 475–80. http://dx.doi.org/10.1016/s0965-9978(98)00043-x.
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Zhao, Jia Quan, Da Peng Hu, Pei Qi Liu, Feng Xia Liu, and Jin Ji Gao. "Thermodynamic Analysis a Novel Wave Rotor Refrigeration Cycle." Advanced Materials Research 805-806 (September 2013): 537–42. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.537.
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As a novel generation of thermal separators, the Wave rotor refrigerator (WRR) has replaced the traditional pressure-wave thermal separator. However, the isentropic refrigeration efficiency still needs to be improved compared with expander. A novel WRR system cycle was built and the system performance was thermal analyzed under various parameters, such as expansion efficiency or compression efficiency of wave rotor. The results are used to compare with the traditional WRR system. It is shown that the advantage provided by this novel cycle over the traditional WRR is an expansion process and a compression process is integrated into one unit, with a higher energy transfer efficiency and simple structure. The isentropic refrigeration efficiency of this novel cycle can be more than twice of the traditional WRR under the pressure ratio of 1.1. The experimental works are carrying out.
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Arkharov, A. M., V. Yu Semenov, S. B. Malakhov, and A. I. Savitskii. "Analysis of working processes in a rotor-wave cryogenerator." Chemical and Petroleum Engineering 48, no. 7-8 (2012): 420–28. http://dx.doi.org/10.1007/s10556-012-9634-z.
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Atanasiu, Catalin George, and Daniel Eugen Buzea. "Researches Regarding Modal Analysis of a Pressure Wave Supercharger Rotor." Applied Mechanics and Materials 332 (July 2013): 319–24. http://dx.doi.org/10.4028/www.scientific.net/amm.332.319.
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This paper aims on comparison between virtual modal analysis and experimental modal analysis of a PWS rotor. A virtual simulation and an experimental analysis were conducted in order to successfully determine the eigen modes of the PWS rotor. Those frequencies are a good thing to know in case of a new PWS development.
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Welch, G. E., S. M. Jones, and D. E. Paxson. "Wave-Rotor-Enhanced Gas Turbine Engines." Journal of Engineering for Gas Turbines and Power 119, no. 2 (1997): 469–77. http://dx.doi.org/10.1115/1.2815598.
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The benefits of wave rotor topping in small (300- to 500-kW [400- to 700-hp] class) and intermediate (2000- to 3000-kw [3000- to 4000-hp] class) turboshaft engines, and large (350- to 450-kN [80,000- to 100,000-lbf] class) high-bypass-ratio turbofan engines are evaluated. Wave rotor performance levels are calculated using a one-dimensional design/analysis code. Baseline and wave-rotor-enhanced engine performance levels are obtained from a cycle deck in which the wave rotor is represented as a burner with pressure gain. Wave rotor topping is shown to enhance the specific fuel consumption and specific power of small- and intermediate-sized turboshaft engines significantly. The specific fuel consumption of the wave-rotor-enhanced large turbofan engine can be reduced while it operates at a significantly reduced turbine inlet temperature. The wave-rotor-enhanced engine is shown to behave off-design like a conventional engine. Discussion concerning the impact of the wave rotor/gas turbine engine integration identifies technical challenges.
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Kablitz, Stephan, Jörg Bergner, Dietmar K. Hennecke, Manfred Beversdorff, and Richard Schodl. "Darmstadt Rotor No. 2, III: Experimental Analysis of an Aft-Swept Axial Transonic Compressor Stage." International Journal of Rotating Machinery 9, no. 6 (2003): 393–402. http://dx.doi.org/10.1155/s1023621x0300037x.
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At Darmstadt University of Technology (Darmstadt, Germany), the Department of Gas Turbines and Flight Propulsion operates a single-stage transonic compressor test stand. Its main purpose is to provide a database for the validation of computational fluid dynamics codes. In addition, it serves as a testbed for new materials and also for the development of new measurement techniques. After setting up the test rig with a baseline rotor (Rotor No. 1), a titanium bladed disk with conventional radially stacked blade sections, a new rotor (Rotor No. 2) was designed, with the addition of considerable amounts of aft sweep and backward lean. The new rotor's flow field and mechanical properties were investigated by using various measurement techniques, including a laser-2-focus setup.
Dissertations / Theses on the topic "Wave Rotor Analysis Codes"
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Sousa, Alves Joao. "Experimental and CFD Analysis of a Biplane Wells Turbine for Wave Energy Harnessing." Thesis, KTH, Mekanik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-124070.
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Several alternative ways of producing energy came up as the world took conscience of the finite availability of fossil fuels and the environmental consequences of its use and processing. Wave and tidal energy are among the so called green energies. Wave energy converters have been under research for the past two decades and yet there hasn’t been one technology that gathered everyone’s acceptance as being the most suitable one. The present work is focused on a self-rectifying turbine for wave energy harnessing. It’s a self-rectifying biplane Wells with an intermediate stator. The main goal is to evaluate the performance of such a turbine. Two different analyses were performed: experimental and computational. The experimental tests were made so that efficiency, velocity profiles and loss coefficients could be calculated. To do so scaled-down prototypes were built from scratch and tested experimentally. The 3D numerical analysis was possible by using a CFD commercial code: Fluent 6.3. Several simulations were performed for different flow coefficients. Three different degrees of mesh refinement were applied and k-ε turbulence model was the one chosen to simulate the viscous behavior of the flow through the turbine. A steady-state analysis is due and two mixing planes were used at the interfaces between the rotors and the stator. In the end comparisons are made between the experimental and numerical results
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Wenger, Christian W. "Analysis of Two-point Turbulence Measurements for Aeroacoustics." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/30837.
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Simultaneous two-point three-component four-sensor hot-wire velocity measurements taken in three flows of aeroacoustic interest are here analyzed. The analyses provide information on the turbulence structure of the flows as it would be encountered by hypothetical noise producing blades passing through the flows. Two-point measurements taken in the first flow, a lifting wake from a rectangular NACA 0012 half wing, are used to calculate space-time correlation functions and 'pointwise' wave number frequency spectra. Two upwash spectra, calculated for locations in the region of the wake that is roughly homogenous in the spanwise direction, are direct estimates of the full wave number frequency spectra at their locations. As such, they are used to perform aeroacoustic calculations, and the results are compared to results achieved using the von Kármán isotropic spectrum. Amiet's approximation, where the wave number frequency spectra can be represented by the correlation length scales is found to hold reasonably well for the measured spectra.
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The two-point measurements in the second flow, a vortex/blade-tip interaction, are analyzed to provide information useful to researchers of blade-wake interaction noise produced by helicopter rotors. Space-time correlation functions and wave number frequency spectra are calculated for five cuts through the region of interaction. The correlation functions provide information concerning the turbulence length scales found in the interaction region. The spectra are compared to the von Kármán isotropic spectrum and found to be greatly different. However, the spectra do bear some resemblance to spectra calculated in the spanwise homogenous region of the lifting wake.
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The two-point measurements taken in the third flow, the wake from a fan cascade, are analyzed to provide information of use to modelers of broadband noise produced through rotor wake/stator interactions. In particular, space-time correlation functions are calculated for a grid of two-point measurements, which allows the estimation of the turbulence structure as seen by a passing stator blade. Space-time correlation functions and wave number frequency spectra are calculated for various stator configurations. The implications of engine operating speed and stator configuration for broadband noise production are discussed.
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<i> [Vita removed March 2, 2012. GMc]</i><br>Master of Science
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Garafolo, Nicholas Gordon. "AN EXPERIMENTAL INVESTIGATION OF MULTIPLE MODE EXCITATION OF AN INTEGRALLY BLADED DISK." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1164047919.
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(9750260), Pawan Jaysing Sutar. "NUMERICAL SIMULATION OF PRESSURE WAVE SUPERCHARGER WITH POCKETS OPERATING AT DIFFERENT SPEEDS." Thesis, 2021.
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<div>Pressure wave supercharger is an application of wave rotor technology that utilizes compression waves produced by high-pressure engine exhaust gas to compress the fresh intake air within the channels. The phenomena within the wave rotor channels are governed by compression and expansion waves initiated when the channel ends are periodically exposed to differing pressure ports. Two incoming fluids are brought into contact for a very short amount of time to facilitate efficient energy and momentum transfer, thereby exchanging pressure dynamically between the fluids by means of unsteady pressure waves. Since the energy transfer is based on unsteady pressure waves, correct matching of waves and ports is essential for optimum results. Mistiming of the waves in the channels is detrimental to the efficient exchange of pressure and low-pressure exhaust scavenging, which ensures minimum exhaust gas recirculation. Due to varying speed and load conditions of the unit to be supercharged, it is not always possible to maintain the rotor speed constant at the design point.</div><div>To mitigate the effects of wave mistiming due to varying speed, a well-designed combination of wall-pockets was used in Comprex® pressure wave supercharger. The wall-pockets are the recesses provided in the endplates of pressure wave superchargers to create necessary pressure zones at desired locations. This thesis details an extensive qualitative and computational investigation of the performance of pressure wave superchargers with pockets. Numerical simulations of pressure wave superchargers have been performed using the wave rotor analysis codes employed at the Combustion and Propulsion Research Laboratory at IUPUI. This work also pays close attention to inspecting the numerical schemes and modeling of different physical phenomena used in each code. A comparative verification of the wave rotor analysis codes has been conducted to ensure that the same fundamental numerical scheme is correctly implemented in each code. The issue of low-pressure scavenging has been demonstrated by simulating the four-port (pocketless) pressure wave supercharger operating at lower speeds. The wall-pockets have been modeled using a simple lumped volume technique. The gas state in the lumped volume of pockets is estimated using the continuity and energy equations such that the net mass and energy fluxes between each pocket and the wave rotor channels are close to zero. The lumped volume models of pockets have been implemented in the four-port wave rotor configurations to simulate the pressure wave superchargers with pockets. The simulation results show that the pockets assist to maintain sufficient pressure in the desired zones to facilitate proper low-pressure scavenging during lower rotor speed operations. The Comprex simulation results have been observed to be in good agreement with experimental data and qualitative analysis. Specific observations on the performance of each code and comprehensive simulation results have been presented.</div>
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Lu, Po-Hung, and 盧柏宏. "Dynamic Analysis of Stator/Rotor and Contact Mechanism for a Ring-Type Traveling Wave Ultrasonic Motor." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/34788185175631848813.
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碩士<br>中原大學<br>機械工程研究所<br>95<br>The thesis is intended to establish an analytic dynamic model and simulation of the traveling wave type ultrasonic motor (USM). The principle of the ultrasonic motor is based on two energy transfers. First is the transfer from electric power to a mechanical vibration by piezoelectric ceramics employed in the stator to induce traveling or standing waves in the stator with frequencies in the ultrasonic range (higher than 20kHz). Secondly, the wave energy in the stator is transferred to the rotor by means of the frictional contact force between them. The model in this study, the modeling technique used is the finite element method, which first incorporates material properties and constitutive equations of the piezoelectric materials and then assumes the complex dynamics of the stator as a one-demonical Euler-beam vibrating in the vertical direction. The model assumes the fixed of the stator as springs and gets the displacement of particles in the surface of stator with tooth by tilting of stator. Simulating the dynamic of the stator based on finite element modeling, and then combining the contact modeling that is established in the interface of stator and rotor to obtain the equations of motion of the motor. In the terms of equations of motion of motor, the rotational speed can be predicted at different preload, and the results of which have a satisfactory agreement with those measured from experimental studies.
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Smith, Keith Cameron. "Coupled Dynamic Analysis of Flow in the Inlet Section of a Wave Rotor Constant Volume Combustor." 2011. http://hdl.handle.net/1805/2969.
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Indiana University-Purdue University Indianapolis (IUPUI)<br>A wave rotor constant volume combustor (WRCVC) was designed and built as a collaborative work of Rolls Royce LibertyWorks, Indiana University-Purdue University at Indianapolis (IUPUI), and Purdue University, and ran experimental tests at Purdue's Zucrow Laboratories in 2009.
Instrumentation of the WRCVC rig inlet flow included temperature and pressure transducers upstream of the venturi and at the fuel delivery plane. Other instrumentation included exhaust pressures and temperatures. In addition, ion sensors, dynamic pressure sensors, and accelerometers were used to instrument the rotating hardware. The rig hardware included inlet guide vanes directly in front of the rotating hardware, which together with concern for damage potential, prevented use of any pressure transducers at the entrance to the rotor. For this reason, a complete understanding of the conditions at the WRCVC inlet is unavailable, requiring simulations of the WRCVC to estimate the inlet pressure at a specific operating condition based on airflow.
The operation of a WRCVC rig test is a sequence of events over a short time span. These events include introduction of the main air flow followed by time-sequenced delivery of fuel, lighting of the ignition source, and the combustion sequence. The fast changing conditions in the rig inlet hardware make necessary a time-dependent computation of the rig inlet section in order to simulate the overall rig operation. The chosen method for computing inlet section temperature and pressure was a time-dependent lumped volume model of the inlet section hardware, using a finite difference modified Euler predictor-corrector method for computing the continuity and energy equations. This is coupled with perfect gas prediction of venturi air and fuel flow rates, pressure drag losses at the fuel nozzles, pressure losses by mass addition of the fuel or nitrogen purge, friction losses at the inlet guide vanes, and a correlation of the non-dimensional flow characteristics of the WRCVC. The flow characteristics of the WRCVC are computed by varying the non-dimensional inlet stagnation pressure and the WRCVC's operational conditions, assuming constant rotational speed and inlet stagnation temperature.
This thesis documents the creation of a computer simulation of the entire WRCVC rig, to understand the pressure losses in the inlet system and the dynamic coupling of the inlet section and the WRCVC, so that an accurate prediction of the WRCVC rotor inlet conditions can be computed. This includes the computational development of the WRCVC upstream rig dynamic model, the background behind supporting computations, and results for one test sequence. The computations provide a clear explanation of why the pressures at the rotor inlet differ so much from the upstream measured values. The pressure losses correlate very well with the computer predictions and the dynamic response tracks well with the estimation of measured airflow. A simple Fortran language computer program listing is included, which students can use to simulate charging or discharging of a container.
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Karimi, Abdullah. "Numerical study of hot jet ignition of hydrocarbon-air mixtures in a constant-volume combustor." Thesis, 2014. http://hdl.handle.net/1805/6249.
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Indiana University-Purdue University Indianapolis (IUPUI)<br>Ignition of a combustible mixture by a transient jet of hot reactive gas is important for safety of mines, pre-chamber ignition in IC engines, detonation initiation, and in novel constant-volume combustors. The present work is a numerical study of the hot-jet ignition process in a long constant-volume combustor (CVC) that represents a wave-rotor channel. The mixing of hot jet with cold mixture in the main chamber is first studied using non-reacting simulations. The stationary and traversing hot jets of combustion products from a pre-chamber is injected through a converging nozzle into the main CVC chamber containing a premixed fuel-air mixture. Combustion in a two-dimensional analogue of the CVC chamber is modeled using global reaction mechanisms, skeletal mechanisms, and detailed reaction mechanisms for four hydrocarbon fuels: methane, propane, ethylene, and hydrogen. The jet and ignition behavior are compared with high-speed video images from a prior experiment. Hybrid turbulent-kinetic schemes using some skeletal reaction mechanisms and detailed mechanisms are good predictors of the experimental data. Shock-flame interaction is seen to significantly increase the overall reaction rate due to baroclinic vorticity generation, flame area increase, stirring of non-uniform density regions, the resulting mixing, and shock compression. The less easily ignitable methane mixture is found to show higher ignition delay time compared to slower initial reaction and greater dependence on shock interaction than propane and ethylene.
The confined jet is observed to behave initially as a wall jet and later as a wall-impinging jet. The jet evolution, vortex structure and mixing behavior are significantly
different for traversing jets, stationary centered jets, and near-wall jets. Production of unstable intermediate species like C2H4 and CH3 appears to depend significantly on the initial jet location while relatively stable species like OH are less sensitive. Inclusion of minor radical species in the hot-jet is observed to reduce the ignition delay by 0.2 ms for methane mixture in the main chamber. Reaction pathways analysis shows that ignition delay and combustion progress process are entirely different for hybrid turbulent-kinetic scheme and kinetics-only scheme.
Books on the topic "Wave Rotor Analysis Codes"
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Paxson, D. E. A numerical model for dynamic wave rotor analysis. National Aeronautics and Space Administration, 1995.
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Paxson, Daniel E. A numerical model for dynamic wave rotor analysis. National Aeronautics and Space Administration, 1995.
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Paxson, Daniel E. A numerical model for dynamic wave rotor analysis. National Aeronautics and Space Administration, 1995.
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Paxson, Daniel E. A general numerical model for wave rotor analysis. National Aeronautics and Space Administration, 1992.
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Paxson, Daniel E. An improved numerical model for wave rotor design and analysis. National Aeronautics and Space Administration, 1992.
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Panel Study of Income Dynamics: Procedures and Tape Codes : 1984 : Interviewing Year, Wave XVII : A Supplement (Panel Study of Income Dynamics: Procedures and Tape Codes). Univ of Michigan Survey Research, 1987.
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A Panel study of income dynamics: Procedures and tape codes, 1983 interviewing year, wave XVI, a supplement. Institute for Social Research, University of Michigan, 1985.
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Zeitlin, Vladimir. Geophysical Fluid Dynamics. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198804338.001.0001.
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The book explains the key notions and fundamental processes in the dynamics of the fluid envelopes of the Earth (transposable to other planets), and methods of their analysis, from the unifying viewpoint of rotating shallow-water model (RSW). The model, in its one- or two-layer versions, plays a distinguished role in geophysical fluid dynamics, having been used for around a century for conceptual understanding of various phenomena, for elaboration of approaches and methods, to be applied later in more complete models, for development and testing of numerical codes and schemes of data assimilations, and many other purposes. Principles of modelling of large-scale atmospheric and oceanic flows, and corresponding approximations, are explained and it is shown how single- and multi-layer versions of RSW arise from the primitive equations by vertical averaging, and how further time-averaging produces celebrated quasi-geostrophic reductions of the model. Key concepts of geophysical fluid dynamics are exposed and interpreted in RSW terms, and fundamentals of vortex and wave dynamics are explained in Part 1 of the book, which is supplied with exercises and can be used as a textbook. Solutions of the problems are available at Editorial Office by request. In-depth treatment of dynamical processes, with special accent on the primordial process of geostrophic adjustment, on instabilities in geophysical flows, vortex and wave turbulence and on nonlinear wave interactions follows in Part 2. Recently arisen new approaches in, and applications of RSW, including moist-convective processes constitute Part 3.
Book chapters on the topic "Wave Rotor Analysis Codes"
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Brahimi, Tayeb, and Ion Paraschivoiu. "Aerodynamic Analysis and Performance Prediction of VAWT and HAWT Using CARDAAV and Qblade Computer Codes." In Entropy and Exergy in Renewable Energy [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96343.
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Wind energy researchers have recently invited the scientific community to tackle three significant wind energy challenges to transform wind power into one of the more substantial, low-cost energy sources. The first challenge is to understand the physics behind wind energy resources better. The second challenge is to study and investigate the aerodynamics, structural, and dynamics of large-scale wind turbine machines. The third challenge is to enhance grid integration, network stability, and optimization. This chapter book attempts to tackle the second challenge by detailing the physics and mathematical modeling of wind turbine aerodynamic loads and the performance of horizontal and vertical axis wind turbines (HAWT & VAWT). This work underlines success in the development of the aerodynamic codes CARDAAV and Qbalde, with a focus on Blade Element Method (BEM) for studying the aerodynamic of wind turbines rotor blades, calculating the induced velocity fields, the aerodynamic normal and tangential forces, and the generated power as a function of a tip speed ration including dynamic stall and atmospheric turbulence. The codes have been successfully applied in HAWT and VAWT machines, and results show good agreement compared to experimental data. The strength of the BEM modeling lies in its simplicity and ability to include secondary effects and dynamic stall phenomena and require less computer time than vortex or CFD models. More work is now needed for the simulation of wind farms, the influence of the wake, the atmospheric wind flow, the structure and dynamics of large-scale machines, and the enhancement of energy capture, control, stability, optimization, and reliability.
Conference papers on the topic "Wave Rotor Analysis Codes"
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Sant, Tonio, and Daniel Micallef. "Disparity Analysis for Three Floating Wind Turbine Aerodynamic Codes in Comparison." In ASME 2019 2nd International Offshore Wind Technical Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/iowtc2019-7509.
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Abstract This paper compares the predictions from three independent aerodynamic simulation tools modelling the time varying rotor thrust and shaft power of floating offshore wind turbines (FOWTs) under different sea wave conditions. These include a Blade-Element-Momentum (BEM) model, a Free-Wake Vortex model (FWM) and a Navier-Stokes based Actuator Disc (AD) model. The study is based on the NREL1 5 MW baseline FOWT installed on the OC4 DeepCWind semi-submersible platform. The rotor speed is maintained constant throughout the analysis, though different rotor tip speeds and sea wave heights and periods are considered. While the three aerodynamic models apply different approaches for modelling the wake, they are all based on a blade element theory (BET) approach for simulating the blade loads. A common set of static aerofoil data is used and corrections to the data for unsteady effects such as dynamic stall are ignored. Thus disparity between the predictions for the surging rotor is primarily due to the different numerical approaches used for modelling the FOWT wake. The time-averaged rotor thrust and power coefficients predicted by the three models were found to be in close agreement with one another at low tip speed ratios and the sea state was found to have marginal effect on these results. However, the disparity in such predictions between the three models was found to increase at high tip speed ratios, with the FWM and the AD models yielding the largest and smallest rotor thrust and power coefficients, respectively. Furthermore, the AD model was observed to exhibit the highest sensitivity to sea state, with a significant increase in the time averaged power coefficient being predicted at the most extreme wave condition. The amplitudes in the thrust and power expressed as a percentage of the corresponding time-averaged values estimated by the three aerodynamic models were found to be in close agreement with one another for the optimal and high tip speed ratios. However, at low tip speed ratios, the BEM predictions were significantly smaller than those estimated by the FWM and AD models.
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Jones, Scott M., and Gerard E. Welch. "Performance Benefits for Wave Rotor-Topped Gas Turbine Engines." In ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/96-gt-075.
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The benefits of wave rotor-topping in turboshaft engines, subsonic high-bypass turbofan engines, auxiliary power units, and ground power units are evaluated. The thermodynamic cycle performance is modeled using a one-dimensional steady-state code; wave rotor performance is modeled using one-dimensional design/analysis codes. Design and off-design engine performance is calculated for baseline engines and wave rotor-topped engines, where the wave rotor acts as a high pressure spool. The wave rotor-enhanced engines are shown to have benefits in specific power and specific fuel flow over the baseline engines without increasing turbine inlet temperature. The off-design steady-state behavior of a wave rotor-topped engine is shown to be similar to a conventional engine. Mission studies are performed to quantify aircraft performance benefits for various wave rotor cycle and weight parameters. Gas turbine engine cycles most likely to benefit from wave rotor-topping are identified. Issues of practical integration and the corresponding technical challenges with various engine types are discussed.
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Materano, Gilberto, and Mark Savill. "Preliminary Design of a Double Expansion Through Flow Wave Rotor: Thermal and Gas Dynamic Analysis." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-94987.
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The wave rotor is a device capable of increasing the pressure of a fluid by deploying shock waves in a transient process. The operation principle is based on the shock tube where shock waves, rarefaction waves and contact waves result from the mixture of fluids with different levels of total pressure. The incorporation of a wave rotor into a gas turbine increases the machine thermal efficiency and reduces fuel consumption, thus allowing the development of new environmentally friendly technologies. The preliminary design of a wave rotor can be achieved by following two fundamental steps. Firstly, it is necessary to carry out a thermal analysis of the cycle in order to obtain the fluid state at each port of the device, secondly to track the different waves generated during the process in order to determine the dimensionality of the wave rotor. The thermal analysis can be accomplished if the performance of the wave rotor is predicted in advance, to set the trajectory of the cycle. The performance prediction can be obtained from the analytical solution of the one-dimensional equations used to describe compressible flow, in a gas dynamic evaluation. Among the available alternatives to perform the gas dynamic analysis, this work considers the algorithm of Weber, because it has proven to be robust by ensuring the mass balance across all the device ports, and also as this technique has not been used previously to evaluate the performance of propulsion gas turbines. In this study, four thermal cycles of gas turbine with a double expansion through-flow wave rotor were considered. These configurations come from changes of some processes in the thermal cycle to a turbofan implemented in business jets, which is set as the baseline engine. In each cycle the wave rotor is exposed to different velocities, expressed as Mach numbers, of the injected air that comes from the compressor, as well as different temperature ratios between this air and the gases that come from the combustion chamber in order to evaluate changes in the overall efficiency of the cycle and the specific thrust. The results obtained from this study show that not all the possible cases can be implemented in propulsion gas turbines, and none of the cases that prove to be suitable has a single point of operation. Rather they have a range of operations with maximum specific thrust and minimum specific fuel consumption, located at different operation conditions.
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Iijima, Kazuhiro, Junghyun Kim, and Masahiko Fujikubo. "Coupled Aerodynamic and Hydroelastic Analysis of an Offshore Floating Wind Turbine System Under Wind and Wave Loads." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20772.
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A numerical procedure for the fully coupled aerodynamic and hydroelastic time-domain analysis of an offshore floating wind turbine system including rotor blade dynamics, dynamic motions and flexible deflections of the structural system is illustrated. For the aerodynamic analysis of wind turbine system, a design code FAST developed by National Renewable Energy Laboratory (NREL) is employed. It is combined with a time-domain hydroelasticity response analysis code ‘Shell-Stress Oriented Dynamic Analysis Code (SSODAC)’ which has been developed by one of the authors. Then, the dynamic coupling between the rotating blades and the structural system under wind and wave loads is taken into account. By using this method, a series of analysis for the hydroelastic response of an offshore large floating structure with two rotors under combined wave and wind loads is performed. The results are compared with those under the waves and those under the winds, respectively, to investigate the coupled effects in terms of stress as well as motions. The coupling effects between the rotor-blades and the motions are observed in some cases. The impact on the structural design of the floating structure, tower and blade is addressed.
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Iancu, Florin, Janusz Piechna, and Norbert Mu¨ller. "Radial Ultra-Micro Wave Rotors (UµWR): Design and Simulation." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13721.
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It has been shown that the wave rotor technology has the potential of improving the performance of gas turbine cycles. Moreover the radial wave rotor is an additional innovation for this technology. Unlike the commercialized axial-flow wave rotor (Comprex®), a radial one has the benefit of using centrifugal forces to improve the compression process or flow scavenging. The geometry of the rotor is much simpler and is ideal for microfabrication, which is relying mainly on two-dimensional processes to create three-dimensional features. This paper is presenting several radial ultra-micro wave rotors (UμWR) configurations and numerical analysis of these rotors. In a radial placement, the wave rotor has four possible configurations: two - general configuration, through-flow and reverse-flow, and each of these could have the low pressure air port positioned at inside or outside of the rotor. Results have been obtained using FLUENT, a Computational Fluid Dynamics (CFD) commercial code. The vast information about the unsteady processes occurring during simulation is visualized.
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Suzuki, Hideyuki, Hajime Shibata, Hiroyuki Fujioka, Shinichiro Hirabayashi, Kimiko Ishii, and Hiroki Kikuchi. "Development of an Analysis Code of Rotor-Floater Coupled Response of a Floating Offshore Wind Turbine." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10444.
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Coupled rotor-floater response analysis is essentially important for the design of Rotor Nacelle Assembly (RNA) and floating support structure of Floating Offshore Wind Turbine (FOWT). The authors have developed an analysis code UTWind for analysis of the coupled structural response. Blades and floater are modeled as frame structure with beam elements. Lumped mass model is use for mooring. Aerodynamic load on blade is calculated by Blade Element Momentum Theory (BEM), and hydrodynamic load is calculated by Hooft’s method, and Morison equation was modified to be applicable to cylindrical element with cross section with two axes of lines symmetry. The equations of motion of rotor, floater and mooring are solved in time domain by weak coupling algorithm. The numerical results by the code were compared with responses measured by experiment in wave and wind-and-wave coexistence field with/without blade pitch control and showed good agreement. Response by negative damping was reproduced by the code and showed good agreement with experiments.
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Vafiadis, K., N. Stergiannis, and A. Tourlidakis. "Computational Flow Analysis of Wind Farms Using a Simplified Rotor Disc Model With Radially Varying Thrust Coefficient." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25006.
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Large scale horizontal axis wind turbines are one of the most promising renewable energy technologies. When they are installed in wind farms (onshore and offshore) they can exploit the most of the available wind energy of a site. The accurate calculation of their aerodynamic interaction due to the wake development is crucial for the design of the layout and the operation of a wind farm. Simulating a wind farm with more than one fully detailed wind turbines and possibly complex terrain geometry requires significant computational power and time. Therefore, the turbine rotors are approximated as discs which behave as momentum sinks. This approach has been adopted in the present study which focuses on the development of a simplified rotor disc model. However, in the present contribution, in order to approximate the axial thrust across the disc in a more accurate manner, a novel model that involves a radially varying thrust coefficient is utilized which is extracted from the CFD full rotor transient analysis results. The analysis is carried out with the use of two commercial CFD codes, ANSYS CFX and ANSYS Fluent for the full rotor and the simplified model, respectively. For the development of the radial distribution of thrust along the blades, both steady and transient computations are carried out and the results are compared against available experimental data. For the full rotor simulation the time-averaged transient results are compared against the steady ones and with the results of the actuator disc approach. Two different turbulence models, k-epsilon and Shear Stress Transport, were used along with the three dimensional RANS equations. The detailed assessment of the differences in the flow field as it is obtained from the steady and transient analysis of both full rotor and actuator disc approximations indicated that a good agreement exists between the two distributions and the existing differences are identified and quantified.
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Lin, Dun, Xinrong Su, and Xin Yuan. "DDES Analysis of Wake Vortex Related Unsteadiness and Losses in the Environment of High-Pressure Turbine Stage." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64152.
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In this work, the flows inside the high pressure turbine (HPT) vane and stage are studied with the help of a high-fidelity delayed detached eddy simulation (DDES) code. This work intends to study the fundamental nozzle/blade interaction with special attention paid to the development and transportation of the vane wake vortex. There are two motivations for this work. On the one hand, the high pressure turbine operates at both transonic Mach numbers and high Reynolds numbers, which imposes a great challenge to modern computational fluid dynamics (CFD), especially for scale-resolved simulation methods. An accurate and efficient high-fidelity CFD solver is very important for a thorough understanding of the flow physics and the design of more efficient HPT. On the other hand, the periodic wake vortex shedding is an important origin of turbine losses and unsteadiness. The wake and vortex not only cause losses themselves, but also interact with the shock wave (under transonic working condition), pressure waves, and have a strong impact on the downstream blade surface (affecting boundary layer transition and heat transfer). Built on one of our previous DDES simulations of a HPT vane VKI LS89, this work further investigates the development and length characteristics of the wake vortex, provides explanations of the length characteristics and reveals the transportation of the wake vortex into the downstream rotor passage along with its impact on the downstream aero-thermal performance.
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Ren, Nianxin, Zhen Gao, and Torgeir Moan. "Long-Term Stochastic Dynamic Analysis of a Combined Floating Spar-Type Wind Turbine and Wave Energy Converter (STC) System for Mooring Fatigue Damage and Power Prediction." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23438.
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In this work, a combined concept called Spar-Toru-Combination (STC) involving a spar-type floating wind turbine (FWT) and an axi-symmetric two-body wave energy converter (WEC) is considered. From the views of both long-term fatigue damage prediction of the mooring lines and the annual energy production estimation, a coupled analysis of wind-wave induced long-term stochastic responses has been performed using the SIMO-TDHMILL code in the time domain, which includes 79200 one-hour short term cases (the combination of 22 selected mean wind speeds * 15 selected significant wave heights * 12 selected spectral peak wave periods * 20 random seeds). The hydrodynamic loads on the Spar and Torus are estimated using potential theory, while the aerodynamic loads on the wind rotor are calculated by the validated simplified thrust force model in the TDHMILL code. Considering the long-term wind-wave joint distribution in the northern North Sea, the annual fatigue damage of the mooring line for the STC system is obtained by using the S-N curve approach and Palmgren-Miner’s linear damage hypothesis. In addition, the annual wind and wave power productions are also obtained by using hourly mean output power for each short-term condition and the joint wind-wave distribution.
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Nageswara Reddy, Pereddy. "Performance Enhancement of Gas Turbine Engines Topped With Wave Rotors and Pulse Detonation Combustors." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14911.
Full textAbstract:
Abstract In the present research work, a novel method of integrating the conventional gas turbine engine with a Wave Rotor (WR) and a Pulse Detonation Combustor (PDC) is proposed to increase the specific work and thermal efficiency of the engine. Two gas turbine engine configurations, viz. (i) Baseline engine topped with a wave rotor and a steady flow combustor (BWRSFC), and (ii) Baseline engine topped with a wave rotor and a pulse detonation combustor (BWRPDC), have been analyzed with and without recuperative systems. In the case of BWRPDC, the principle of quasi-steady expansion of detonation products through a nozzle into the ejector to entrain and eject the bypassed compressed air along with detonation products exhausted from WR, and a steady expansion of remained detonation products of PDC through the WR to provide the required energy transfer to further compress and supply the un-bypassed compressed air to PDC, has been considered. The pressure of the ejected gases from the ejector will be 25% to 35% higher than the air pressure delivered by the compressor of baseline engine and can develop more specific work with enhanced thermal efficiency when expanded in the turbine. A computer code is developed in MATLAB to simulate the engine performance with and without recuperation / regeneration. For thermodynamic calculations, two un-recuperated micro-turbine engines called C-30 and C-60 made by Capstone Turbine Corporation are considered. C2H4/air is taken as the fuel-oxidizer. The variation in specific work, and thermal efficiency with wave rotor pressure ratio has been investigated for C-30 and C-60 engines. Further, a sensitivity analysis of the performance of BWRPDC with a change in the Entrainment Coefficient (EC) of ejector has also been made.
Reports on the topic "Wave Rotor Analysis Codes"
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Wissink, Andrew, Jude Dylan, Buvana Jayaraman, et al. New capabilities in CREATE™-AV Helios Version 11. Engineer Research and Development Center (U.S.), 2021. http://dx.doi.org/10.21079/11681/40883.
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CREATE™-AV Helios is a high-fidelity coupled CFD/CSD infrastructure developed by the U.S. Dept. of Defense for aeromechanics predictions of rotorcraft. This paper discusses new capabilities added to Helios version 11.0. A new fast-running reduced order aerodynamics option called ROAM has been added to enable faster-turnaround analysis. ROAM is Cartesian-based, employing an actuator line model for the rotor and an immersed boundary model for the fuselage. No near-body grid generation is required and simulations are significantly faster through a combination of larger timesteps and reduced cost per step. ROAM calculations of the JVX tiltrotor configuration give a comparably accurate download prediction to traditional body-fitted calculations with Helios, at 50X less computational cost. The unsteady wake in ROAM is not as well resolved, but wake interactions may be a less critical issue for many design considerations. The second capability discussed is the addition of six-degree-of-freedom capability to model store separation. Helios calculations of a generic wing/store/pylon case with the new 6-DOF capability are found to match identically to calculations with CREATE™-AV Kestrel, a code which has been extensively validated for store separation calculations over the past decade.