Abstract
The effects of the length of stacks, both the prime mover and the heat pump, are discussed for the cooling temperature of the loop-tube thermoacoustic system. Result of experiment actually, it was suggested there were some optimum length of stack. Two influences by changing the stack length are thought; the sound attenuation and the energy exchange area. When the decrease of sound attenuation make the cooling effect increase, on the other hand, the decrease of the energy exchange area in the stack makes the cooling effect decrease. As the results of the combination of these effects, some optimum conditions exist depending on the length of both the stacks. Moreover, it is important to measure the temperature in the stack in requesting the best length of the stack.
