Thermoacoustic theory gives two types of heat flux. One is proportional to thermal expansion coefficient of working fluid and contributes to heat-pumping effect of cryocoolers. The other is proportional to the heat capacity and axial gradient of temperarture. This acoustically enhanced heat-conduction term corresponds to one of regenerator losses, shuttle loss of displacer and a part of heat-flux in conventional “Dream Pipe.” Heat transports in the “Dream Pipe” are discussed in terms of thermoacoustics of inviscid fluid. Results of thermoacoustic theory are compared with experiments of dream pipe of which working fluid is liquid water. Good agreements of thermoacoustic theory with experiments suggest that thermoacoustic theory of inviscid fluid is useful for accounting regenerator loss and shuttle loss of cryocoolers.
