1. Definition of the thermoacoustic effect

Interest in thermoacoustic systems dates back to around the 1980s, and LANL (Los Alamos National Laboratory, Swift, Backhaus) and Penn State University (Garrett) can be considered the forerunners in the field. Going even further back in time, it would appear that Rayleigh was the first to notice that mechanical energy could be produced if air was heated during its compression phase and cooled during its expansion (Sondhauss tube studies, 1850 and Rijke, 1859). Later, Rott coined the term thermoacoustics (1969 to 1980) and established its theoretical foundations.