中文摘要：

基于弱非线性热声理论,对热声换热器的换热特性进行了理论研究.获得了平行平板通道内二阶周期平均热流的解析解,并指出存在临界声导率比的模｜Ya｜cr^I,使得二阶周期平均热流为零.当实际声导率比的模大于｜Ya｜cr^I时,振荡流体从外热源吸热,为吸热器;当实际声导率比的模小于｜Ya｜cr^I时,振荡流体向外放热,为放热器.获得了平行平板通道内二阶周期平均温度的解析解.计算分析了工作流体的物性参数、流动参数以及声导率比对二阶周期平均温度分布的影响,为进一步考察换热系数提供了依据。

英文摘要：

In terms of the understanding on nonlinear physical essence of the non-zero time-averaged energy conversion,a locally-analytical heat transfer models for parallel-plate flowing passages subjected to oscillating flow were developed.The analytical expressions show that the time-averaged heat flux is a complex function of thermal properties,dynamic Reynolds number and acoustical admittance and there exists a critical acoustical admittance ｜Ya｜cr^I making the heat flux being zero. Thermoacoustic heat exchanger acts as a heat absorber when actual acoustical admittance is higher than ｜Ya｜cr^I,and acts as a heat releaser when actual acoustical admittance is lower than ｜Ya｜cr^I. Moreover,a simplified expression for second-order time-averaged transversal temperature distribution was derived.Thus,the influence of thermal properties,dynamic Reynolds number and acoustical admittance on the dimensionless temperature distribution is discussed.