Thermoacoustic converters

This article is a follow-up to the two articles "Thermoacoustic effect" [BE 8 060] and "Thermoacoustic motors and coolers" [BE 8 061] . It makes extensive use of their theoretical concepts and results. In addition to this very specific knowledge, the modeling of thermoacoustic systems requires the use of analogies with electrical networks, so some knowledge of this field is also necessary. The problem of dimensioning a thermoacoustic machine, as well as that of its overall optimization, is not currently solved in a simple or systematic way. In reality, the "design" of a device is carried out more or less by trial and error, either by applying the rules of similarity based on knowledge acquired from an existing machine with known operation, or by defining an acoustic structure a priori and optimizing certain parts according to the results obtained using more or less sophisticated models (DeltaE program, wave equations, linear thermoacoustic theory...). These models have generally been developed to match the experimental results of a given prototype as closely as possible, and are therefore not really universal. The article [BE 8 063] deals with the combination of thermoacoustic motors and receivers, and reports on recent advances in the realization of these systems.