A review of supersonic jet aeroacoustics: Physics, prediction, and mitigation

Supersonic jet aeroacoustics is a detailed study of intense aerodynamic noise in aerospace propulsion applications, particularly in relation to military aircraft and launch vehicles. The primary motivation of this review is to elaborate in detail on the various noise-generation mechanisms associated with supersonic jets in aerospace propulsion applications, particularly in military aircraft and launch vehicles. The generation of jet noise results from multiple interactions among shear-layer instability, its compressibility effects, and shock–cell structures, producing a noise characteristic distinct from that of subsonic flows. This review paper presents a systematic and extensive study of supersonic jet noise arising from the above-mentioned mechanisms, based on pertinent literature and supported by facts and figures, including broad-band shock-associated noise, Jet Screech, and noise due to turbulent mixing. It traces the development of theoretical approaches, from past acoustic-analogies to the latest aeroacoustic measurement techniques, which encompass complete experimental and numerical analysis methods to provide in-depth and comprehensive information on various scaling laws, the directivity patterns of jet acoustics, and modern-day challenges in predictive modeling. This review paper also represents the recent developments in the techniques of active and passive jet-noise control. Be all and end all, this review recapitulates the key issues and future research predictions to advance the reliability of modeling and the efficacy of supersonic jet noise reduction.