Numerical Simulation And Analysis On Acoustic Characteristics Of Thermoacoustic Components

Thermoacoustic engine is a new type of engine, which is based on the thermoacoustic effect, Due to its advantages of no-pollution,simple structure and high reliability, research on thermoacoustic engine are becoming new hot-points.The main component of thermoacoustic engine is cold (hot) heat exchanger, regenerator and the resonant tube. The role of resonant tube in the system is influence resonance frequency,maintain sound field and storage part sound energy; Thermoacoustic effect, the basic mechanism of the thermoacoustic engine, occurs in the regenerator. As a result,these two components are the core component and a research hot-point in the field of thermoacoustic engine. Recently, the commercial computational fluid dynamics (CFD) software FLUENT was introduced to the thermoacoustic research, after systematic understand previous research studies, the paper continues related research work about resonant tube and regenerator. Mainly includes the following respects:1. The feasibility about simulated sound field in thermoacoustic system by Fluent is discussed. The pressure distribution along the straight resonator were calculated on the wave theory and simulated by Fluent,The results are well in agreement,which confirm that Fluent can be used in simulating the distribution of acoustic field from another side.2. The study on the pressure ratio of the thermoacoustic resonator in different operating pressure. To several different type resonant tube of the standing wave thermoacoustic prime mover engine, the paper first study on the pressure ratio in different operating pressure. Results show that: The pressure distribution of resonator is relate with the type,length and so on; And the higher operating pressure is helpful to the pressure distribution of the resonator. In our existing condition of experiment, verifying the results of numerical simulation by experiment.3. Numerical simulation and analyses of oscillating flow characteristics in the regenerator of standing wave thermoacoustic engine. The study sample is the parallel plate regenerator which is designed and manufactured by our research group. A software on computational fluid dynamics,Fluent, is introduced to simulate the oscillating characteristics in the parallel plate fold regenerator. Results show that the pressure,velocity and temperature is changing with the change of time and location;The numerical simulation results also proved that acoustic structure in the standing wave system is not ideal standing wave.