Experimental validation of a heat exchanger model for thermoacoustic applications

Thermoacoustics is a promising technology for energy conversion purposes. Among the bottlenecks limiting a large diffusion of thermoacoustic devices, there are heat exchangers, whose behaviour in oscillatory flows is rather different than those working in stationary flows. Furthermore, the classical linear acoustic theory in the frequency domain cannot predict with high-fidelity the thermo-fluid dynamics of such heat exchangers. In this article, a CFD model based on a standing wave device including a parallel plate heat exchanger is proposed. The setup is inspired by a similar prototype of a thermoacoustic engine in which the performance of the ambient heat exchanger was tested. The results of the CFD model are therefore compared, in terms of the temperature difference between fluid and solid wall in the heat exchanger, average heat flux and Nusselt number, with experimental data showing a satisfying agreement.