回热器工作的热声机理

Thermoacoustic Mechanism of Rgeenerator in Regenerative Cryocoolers

从热致声的瑞利判据出发，给出了回热器工作的数学模型。据此分析证明了回热器不仅是逆流换热器，而且也是一个热声转换部件，即在纵向声波与横向热量波动的耦合下，可以实现热致声或声泵热或声输热，给出了在理想流体条件下，控制声场条件以调节或控制横向温差，从而改变回热器工作模式的原则方法。进而指出，对于用实际耗散流体的实际回热器，由耗散性质所造成的热声效应截面分布是回热器工作性能的另一决定因素。

The thermoacoustic essence of the regenerator in the regene-rative heat engine is discussed in this paper.Based on Rayleigh criteria the thermoacoustic energy conversion can be achieved under the favorable con-ditions,which is due to the oscillatory transverse heat exchange between the solid matrix of regenerator and the fluid working substance caused by the pressure fluctuation,namely acoustic wave.This reveals that the regenerator is not merely a heat exchanger, but is essentially a thermoaco-ustic device.In the prime-mover heat engine,heat flows from a high-tempe-rature source to a low-temperature sink and generates acoustic power in the regenerator,while in the refrigerator,acoustic power is used to pump the heat from a low-temperature source to a high temperature sink through the regenerator.