谐振管中混合工质的热声分离效应

THERMOACOUSTIC SEPERATION PHENOMENA OF THE RESONATOR WITH MIXTURE WORKING GASES

本文在可压缩SIMPLE算法的基础上,基于先求解二维热声谐振腔内的速度场和温度场,然后利用求出的速度和温度值求解组分浓度场的思路,对混合工质的热声分离现象进行了数值研究。研究结果表明:在热声效应和热扩散效应共同作用下,声波能够将混合物中的两种气体分别泵向谐振腔的压力腹点和节点,使得混合气体在声波传播方向上逐渐分离。另外,通过考察5种不同管径下谐振管内径向浓度的变化规律,详细研究了浓度边界层在径向上的影响范围以及不同管径下的分离效率,并提出最佳管径应为16倍浓度渗透深度左右。

A 2-D numerical model has been developed to study the thermoacoustic separation effect of the resonator in this paper.Computation methods based on the compressible SIMPLE algorithm are proposed to solve the velocity field,temperature field of the resonator.Then the concentration field of certain component which comprises the mixture can be attained on the basis of the former velocity and temperature solution.It is shown that the light component and heavy one can be pumped to the pressure node and antinode separately by thermoacoustic effect and thermal diffusion effect,which results in seperation of the mixture along the propagation direction of sound wave.Then the resonators with 5 diameters have been simulated to study the influence of radial concentration distribution of the mixture working gases.The influence range of the radial concentration boundary layer and the seperation ratio in different diameter tubes are detailed investigated.Finally,results reveal that the optimal diameter of the resonator will be about sixteen times more than the concentration penetration depth of the working gases.