Thermoacoustics as a tool for teaching thermodynamics in secondary schools

Abstract

This article presents a possible way of teaching thermodynamic cyclic processes to secondary school students and also explains the importance of teaching heat pumps. Two simple classroom experiments demonstrating heat engines and heat pumps are described. The first is a thermoacoustic test-tube heat engine, which emits a loud sound due to heating. The second is the reverse, a thermoacoustic refrigerator, where a temperature difference is generated by a loud sound. A qualitative, secondary school level explanation of the observed phenomena is suggested. To quantify the performance of different cyclic processes, the terms efficiency and coefficient of performance are introduced and defined.