Lattice Boltzmann Simulation Of Acoustic Oscillation In Thermoacoustic Resonant Tube

Thermoacoustic refrigerator is a type of environmentally friendly new refrigerator, its advantages make it have been researched all over the word. However, The working environmental of thermoacoustic refrigerator is non-linear coupling of acoustic and thermal, the space and time multi-scale effects and the flows with porous medium, which make it very difficult in theory research and numerical simulation. Therefore, it is necessary to investigate new simulation analysis method. Our team has been using lattice gas method to study the thermoacoustic engine and made some progress. The aim of present thesis work is to use the lattice Boltzmann(LB) method to study the characteristics of medium oscillation in resonator.Suitable model (D2Q9 total energy distribution function lattice Boltzmann model) was selected for the resonant. The characteristics of the media oscillation and heat transfer are studied by numerical simulation. Suitable boundary condition for lattice Boltzmann simulations also are selected for the physical boundary. At the same time, non-equilibrium extrapolation method is applied to dealing with isothermal boundary.The acoustic attenuation is simulated by D2Q9 total energy distribution function lattice Boltzmann model, which show the reliability of the lattice Boltzmann model. The media oscillation characteristics in stable state of the resonant which was drived by a piston are analyzed. The effect of the driven frequency on the density amplitude is analyzed. The nonlinear oscillation phenomena of the resonator is analyzed preliminarily, the consistency of the results predicted with the experimental results shows the reliability of using LB to simulate media oscillation problem in resonator.Finally, the resonance which has stacks in it is analyzed. The effects of the impedance of stacks to media oscillation are analyzed by comparing the discrepancy of phase angle and amplitude. At last, we concluded that the effects of the reactance can be neglected and the effects of the resistance is very obvious.