用于热声系统的多孔型回热器模型

Model of regenerator with porous types in thermoacoustic system

对用于热声系统中的弯曲流道的多孔材料回热器建立了理论模型.该模型将Brinkman-Forchheimer扩展达西方程作为动量方程,并在动量方程与能量方程中保留二次项.推导得到了多孔型回热器的波动速度、总能流、热流和温度差表达式.定义了无量纲参数Sw和达西数,在热声制冷机系统中,分析了不同Sw下波动速度的截面分布和热流随达西数的变化.数值分析了特定工况下回热器冷热端温差,并与Swift经典线性理论、Tasnim理论和实验结果进行对比.结果表明所建模型与实验结果符合得更好,验证了模型的适用性.

A theoretical model of a regenerator with porous materials in a thermoacoustic system was built up. The Brinkman-Forchheimer equation was used as the momentum equation and the second or- der items in the dissipation were kept in both momentum and energy equations. The expressions of os- cillating velocity, total power, heat flux and temperature difference were derived. Dimensionless pa- rameters, including Sw number and Darcy number, were defined. With different Sw numbers, the dis- tributions of the velocity perpendicular to the wave propagation direction and heat flux versus Darcy number were analyzed in a thermoacoustic refrigerator. Furthermore, the temperature difference be- tween the ends of the regenerator was calculated and compared with the results of Swiftrs theory, TasnimPs model and experiments. Results show that the simulation results agree well with the experi- mental results and verify the aDulicabilitv of this model.