Thermoacoustic | Advanced Thermal Science and Flow Control Lab

Thermoacoustic

TAE can be divided into two categories. One is the engine which converts the heat energy to mechanical vibration; the other is the refrigerator which generates the temperature gradient by the actuator (speaker or piezoelectric material).

The TAE is composed by the resonator, stack, and heater. According to the review paper of Swift, when the heater is applied the heat energy to the stack which reached a higher temperature gradient than a critical value, and the air column will generate the air vibration inside. The pressure and velocity in the resonator was out of phase (90°) which is in a form of standing wave in a resonator.

Thermoacoustic engine (TAE) is an energy conversion device which converts the heat energy to acoustic energy or vice versa. The advantages of TAE are no moving part (at most one), no carbon dioxide and Freon emission, which is environment friendly. In 1999, Swift had constructed a TAE which can achieve an efficiency of 30%. It is very comparable to combustion engine (25~40%). In application, TAE can be applied to use the waste heat or solar energy to generate electricity [2], to be as a gas liquefier and another novel idea is the application of the microcircuits cooling. Using the TAE in cooling can be free from extra energy input and without noise (if it operates in ultrasonic region). The TAE can reduce the energy consuming and use the energy more efficiently.