Acoustic and Thermoacoustic Jet Propulsion

Abstract This manuscript bridges the fields of jet propulsion, synthetic jets and thermoacoustic engines. We put forward the case that acoustic air jets can be considered as a consistent approach for propulsion systems. Hitherto, studies on synthetic jet propulsion have been scattered and rather subsidiary. Furthermore, investigating with the perspective of propulsion can give new insights to the field of synthetic jets, and the physics of propulsion. We developed and characterized the propulsion properties with regard to several relevant parameters such as geometric factors, frequency and intensity of acoustic jets produced electromechanically and thermally. We demonstrated 10.4 mN and 2.7 mN thrust in the acoustic and thermoacoustic modes respectively, using compact tabletop assemblies. The physical mechanism of the jets has been modelled, simulated, verified with Schlieren imaging and laid in the perspective of adherent literature. Similarities and differences with regard to traditional jet propulsion systems are discussed. As an essentially unexplored avenue, several improvement directions are indicated.