Applying Diverging Tube for the Low-Temperature Drive in a Loop-Tube-Type Thermoacoustic System

Abstract

In this report, we propose a low-temperature driving method for loop-tube-type thermoacoustic cooling systems with a diverging tube. We specifically examine the sound field within a loop tube and the temperature at the top of a prime mover stack when the diverging tube position is changed. Experimental conditions included constant input heat energy and the temperature at the bottom of the stack. The diverging tube position was adjusted to increase the efficiency of energy conversion from heat energy to sound energy. Furthermore, the temperature at the top of the prime mover stack decreased by about 500 °C, from 845 to 345 °C, compared with that in systems without a diverging tube. The results suggest that the phase difference between the pressure and particle velocity in the prime mover stack improved. The diverging tube system was driven by the low-temperature difference because the energy conversion efficiency was increased.