Cascaded Thermoacoustic amplifier

In this study, we explore the amplification of an incident acoustic wave using the thermoacoustic effect and its applicability for low-temperature energy harvesting. The thermoacoustic effect can be exploited to develop thermoacoustic engines, whose potential for thermal energy harvesting has been extensively studied. In their simplest form, they consist of a porous material inserted in a waveguide, in which a temperature difference is applied and leads to the generation of a thermoacoustic instability. Here, we propose the theoretical and experimental study of an alternative system to the conventional thermoacoustic engine. The system considered here differs from the typical engine in that it exhibits no self-excited instabilities, but only relies on the amplification of an acoustic wave. The experimental set-up consists of a cascaded network of heated porous materials, coupled to an acoustic source and an alternator. This device allows to control several parameters, such as the operating frequency and input power, and it can be designed to achieve a high amplification ratio. Our work offers a new perspective on energy harvesting using the thermoacoustic effect.