Construction and testing of a steel-wool regenerator within a looped travellingwave thermoacoustic engine

This paper investigates the feasibility of making low cost regenerators of stainless steel wool (scourers). The steel wool is carefully cut and uniformly pressed into a purpose built thin-walled "can" using controlled compression loads to obtain the required porosity and equivalent hydraulic radius. Such regenerators are then installed in a looped-tube travelling-wave thermoacoustic engine to test their performance. In addition, two more conventional stacked mesh-screen regenerators with a similar hydraulic radius are also tested under the same conditions to serve as benchmarks for the low-cost steel wool regenerators. The testing includes the onset temperature difference (minimum temperature difference required to start the acoustic oscillation in an engine), the pressure amplitudes, and the acoustic power circulating in the looped resonator. The measurement results are compared with each other and discussed in detail.