Thermoacoustic prime mover for thermal management.

Abstract

Because thermoacoustic prime movers can operate over a wide range of temperature differences across the stack, they can be used in thermal management applications. Depending on their geometry and frequency of operation, the onset temperature differences for oscillation can vary by a few hundred degrees. This is attractive for low‐temperature difference applications, as in computers and electronics, and for high‐temperature differences as in power plants and automotive industry. Thermoacoustic devices developed here for the mid‐audio frequency up to the ultrasonic range require special materials for the stack, heat exchangers, resonators, and assembly components. A critical issue is the thermal coupling of the acoustic device to the source of heat; it is based on mechanical contact and thermal compounds. The above development led to a variety of small thermoacoustic engines, which ranged in size from 5 cm down to a few millimeters in length. An important benefit of the above approach is that the devices can generate electricity by means of piezoelectric elements; this provides energy conversion from heat to sound to electricity. The working fluid is air at 1 atm.