Abstract
Onset temperatures of a spontaneous gas oscillation occurring in a looped tube thermoacoustic engine were numerically calculated. The looped tube engine had two regenerators inside a looped tube. In the calculation, the relative position between the regenerators was changed. As a result, it was found that there is the optimum relative position and the onset temperature with the optimum one is 108℃. This value is lower than the onset temperature of the looped tube with one regenerator by 170℃.
