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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2016, Vol. 37 ›› Issue (7): 2091-2101.doi: 10.7527/S1000-6893.2015.0207

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

A quasi-one-dimensional nonlinear model of an open-closed standing-wave thermoacoustic engine

HOU Wei1, WANG Xiaoyu2, JING Xiaodong2, SUN Xiaofeng2   

  1. 1. AVIC Academy of Aeronautic Propulsion Technology, Beijing 101304, China;
    2. School of Energy and Power Engineering, Beihang University, Beijing 100083, China
  • Received:2015-06-03 Revised:2015-07-20 Online:2016-07-15 Published:2015-08-03
  • Supported by:

    National Basic Research Program of China (2012CB720200); National Natural Science Foundation of China (51236001)

Abstract:

A quasi-one-dimensional nonlinear model of a standing-wave thermoacoustic engine with a quarter-wavelength resonator is presented. The model is based on cross-sectional averaged equations and is solved by high-order low-dispersion numerical schemes. Considering the acoustic reflection and radiation at the open end, broadband time-domain impedance boundary conditions are employed so that oscillation frequency can be self-adaptive. The impedance is expressed in the mathematical form of partial fraction expansion with complex-conjugate residues and poles, so that the convolution of the impedance with the velocity can be calculated by efficient and causal recursive convolution. Pole-residue pairs of the impedance can be optimized in the frequency domain. Critical temperature difference of an open-ended standing-wave thermoacoustic engine can be predicted and the time-domain simulation shows that the pressure oscillation undergoes a nonlinear amplifying process and eventually reaches saturation amplitude. Numerical results agree very well with the experiment for a small-scale thermoacoustic engine. The simulation results for different stack geometries are included.

Key words: thermoacoustic engines, nonlinear, model, broadband, time-domain impedance boundary condition

CLC Number: