Influence of stack geometry and resonator length on the performance of thermoacoustic engine

Thermoacoustic engines convert heat energy into high amplitude sound waves, which is used to drive thermoacoustic refrigerator or pulse tube cryocoolers by replacing the mechanical pistons such as compressors. The increasing interest in thermoacoustic technology is of its potentiality of no exotic materials, low cost and high reliability compared to vapor compression refrigeration systems. The experimental setup has been built based on the linear thermoacoustic model and some simple design parameters. The engines produce acoustic energy at the temperature difference of 325–450 K imposed along the stack of the system. This work illustrates the influence of stack parameters such as plate thickness (PT) and plate spacing (PS) with resonator length on the performance of thermoacoustic engine, which are measured in terms of onset temperature difference, resonance frequency and pressure amplitude using air as a working fluid. The results obtained from the experiments are in good agreement with the theoretical results from DeltaEc.

► Effect of plate thickness, spacing & resonator length on performance is presented.
► Higher onset temperature difference was obtained for 0.3 mm thick plates than 0.5 mm.
► Pressure amplitude increases for higher plate spacing and resonator length.
► Frequency decreases for higher plate spacing and resonator length.
► A 230–250 Hz frequency of waves generated is enough to run thermoacoustic refrigerator.