Performance investigation and construction of a traveling wave thermo-acoustic engine

The current development of thermo-acoustic devices suggests that there is a possibility to enhance their performance even further. This technology could potentially contribute to the effort to swap conventional pollutant energy refrigerators/generators with environmental friendlier systems in the forthcoming years. The configuration of the regenerator is so far believed to be one of the factor that could contribute to the improvement the performance of the engine. This paper aims to investigate the behaviour of a designed thermo-acoustic engine when changing the porosity of the regenerator. It also aims to provide guidance on the construction, from mostly scrap and cheap materials, of a traveling wave looped-tube thermo-acoustic engine capable of generating higher sound level. The design is conducted using a code program named Design Environment for Low-Amplitude Thermo-acoustic Energy Conversion that helps to simulate in fine details the performance of the device. Three ceramic substrate blocs of different porosities have been considered as regenerators during the simulation. The results showed that the smaller porosity produced higher acoustic power. The higher performing bloc was subsequently used to develop and test a physical prototype. The constructed looped-tube thermo-acoustic engine produced a sound level of 121.4 decibel, just above the minimum auditory pain threshold.