Numerical simulation of a thermoacoustic couple (original) (raw)

A new spice-like modeling tool for bio- and electro- acoustic systems including thermoviscous effects

HAL (Le Centre pour la Communication Scientifique Directe), 2012

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Proceedings of the 3rd International Workshop on Thermoacoustics : 26-27 October, 2015, University of Twente, The Netherlands

2015

Thermoacoustic refrigeration systems: recent developments TS02 Paweł Owczarek Details and experimental results of a stand-alone container cooled by a solar driven multi-stage traveling wave thermoacoustic system TS04 Chris Lawn Optimization of the loop in a travelling-wave thermo-acoustic engine TS05 Maurice-Xavier Francois The VALTA project: full scale conversion of CHP engine flue gas heat into electricity 12:20 13:20 Lunch Grand café 13:20 14:40 Session 2a Erlenmeyer AE05 Douglas Wilcox Development of a compact thermoacoustic-Stirling electric generator AE02 Jeffrey Lin High-fidelity simulations of a standing-wave thermoacousticpiezoelectric engine AE04 Bakhtier Farouk Signal conditioning of carbon nanotube loudspeaker AE01 Ken Kaneuchi Evaluation of bi-directional turbines using the two-sensor method 14:40 14:50 Coffee The Gallery 14:50 16:10 Session 3a Erlenmeyer AE03 Johan Brussen Modeling and controlling the generator of a thermoacoustic Stirling engine AE06 Maurice-Xavier Francois Space thermoacoustic radio-isotopic power system: SpaceTRIPS TS15 Hiroaki Hyodo Dynamics of forced synchronization in thermoacoustic system 16:10 16:20 Coffee The Gallery 16:20 17:20 Session 4a Erlenmeyer TC01 Marialuisa Napolitano The role of stack non acoustic parameters on thermodynamic performance of standing wave devices TC02 Esmatullah Maiwand Sharify CFD study of oscillatory flow around parallel plates in a traveling-wave thermoacoustic engine

3rd international workshop on thermoacoustics, University of Twente, 26-27 October 2015

Proceedings of the 3rd International Workshop on Thermoacoustics

2015

A Simple Model of Thermoacoustics: A Single Plate in a Stationary Wave

2009

In this article the author presents a model developed by Nicholaus Rott [6] and used fo the first time by Gregory Swift [7]. This model presents how a simple plate introduced in a standing wave can influence the fluid near the plate. The model represents the basis of the thermoacoustic engines [5], [7]. [8]. REFERENCES [1]. Adrian BEJAN, Advanced Engineering Thermodynamics. Wiley, second edition, 1997. [2]. Dan ANDREI, George ANDREI, Approche theorique pour la propagation d’ondes dans les milieux elastiques,Analele Universităţii ,,Dunărea de Jos“ din Galaţi, fascicola IV, ISSN 1221-4558, 2006. [3]. George ANDREI, Approche theorique a l’etude des echangeurs de chaleur dans les systemes thermoacoustiques, Rapport de Stage, Institut de Physique Nucleaire d’Orsay, France, Juillet 2005. [4]. George ANDREI, Thermoacoustic systems used in the heat transfer, 2 nd PhD Rapport, „Dunarea de Jos” University of Galaţi, january, 2006. [5]. George ANDREI, Acoustical and Thermal Studies of the heat...

Non-normality of thermoacoustic interactions: an experimental investigation

47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2011

Voltage supplied to the acoustic driver ρ u Steady state density in the zone, upstream of the heater σ Standard deviation of the inner product | < p 1 , p 2 > | τ Non-dimensional time lag between unsteady heat release rate and acoustic velocity θ Phase difference between the first and second eigenmodes Subscript f Location of the heater source i, j Indices for the eigenmodes rms Root mean square value Superscript −, + Locations just upstream and downstream of the heater source Symbols * Complex conjugate δ(x) Dirac-delta function

The calculation of thermoacoustic oscillations

Journal of Sound and Vibration, 1995

Thermoacoustic oscillations occur in a wide variety of practical applications in which heat is supplied to an acoustic resonator. A simple geometry is investigated systematically to determine the importance of various flow parameters on the frequency of the oscillations. Detailed consideration of elementary examples shows that the form of the coupling between the heat input and the unsteady flow has a crucial effect on the frequency of oscillation. The same elementary examples are used to compare how well (if at all) different calculation methods in the literature account for this influence. A mean flow and a distributed region of heat input significantly complicate the analysis of thermoacoustic oscillations and are often neglected. Model problems are used to illustrate that mean flow effects can become significant even at modest inlet Mach numbers, and to indicate circumstances under which a distributed heat input may be treated as concentrated.

Simulation Modeling of Thermoacoustic Cooling and Refrigeration

The International Journal of Acoustics and Vibration, 2010

Conventional refrigeration requires comprehensive power, control, and maintenance systems, all at high costs. As a result it is promising to have an alternative method, which is capable of creating cryogenic refrigeration with no moving parts, a clean energy source, and with a relatively simple design and cheap components. This could be achieved through thermoacoustic cooling techniques, which is based on the oscillation of sound waves to circulate heat between high and low heat exchangers within a well-designed thermoacoustic device. In this study an inclusive acoustic model has been proposed, in which the main parameters have been determined to build up a matrix of constituted engineering-mathematical equations that form the main structure of the modelling process. This modelling has coupled with its associated thermodynamical parameters to form the appropriate thermoacoustic model, which allows for the scaling of parameters, determination of performance rate, and enables refrigeration-performance enhancement. Our results show that the model can provide a precise margin of applications for each parameter of thermoacoustic refrigeration for different working fluids. Also, it is possible to determine the numerical ranges of efficient cooling for absorbed and released heat (q c , q H), maximum-pressure amplitude (P m) and sound intensity (I), respectively.

Numerical study of flow and energy fields in thermoacoustic couples of non-zero thickness

A limitation in many previous numerical studies of thermoacoustic couples has been the use of stack plates which are of zero thickness. In this study, a system for modelling thermoacoustic couples of non-zero thickness is presented and implemented using a commercial CFD code. The effect of increased drive-ratio and plate thickness upon the time-average heat transfer through the stack material is investigated. Results indicate that the plate thickness strongly controls the generation of vortices outside the stack region, perturbing the flow structure and heat flux distribution at the extremities of the plate. An increase in plate thickness is also shown to improve the spatial integral of the total heat transfer rate but at the expense of increased entropy generation.

Nonlinear modeling of thermoacoustic systems

2015

Thermoacoustic systems convert energy from heat to acoustic power and vice versa. These systems have commercial interest due to the high potential efficiency and low number of moving parts. To numerically predict the performance of a thermoacoustic device inherent nonlinearities in the system, such as thermoacoustic streaming and generation of harmonics need to be taken into account. We present a nonlinear frequency domain method with which these nonlinearities in thermoacoustic systems are modeled in a computationally efficient manner. Using this method, the nonlinear periodic steady state of a thermoacoustic engine can directly be computed, without computing the long initial transient of the system. In this publication, the developed method is applied to compute the periodic steady state of an experimental standing wave engine. The results obtained match well with experimental data.

Numerical simulation of a thermoacoustic couple (original) (raw)

Related papers