Aircraft noise severely impacts the health and livelihood of travelers, airport workers and nearby residents. One of the dominant sources of aircraft noise is jet noise, which is defined as the noise generated by a jet flow in the absence of obstacles. Although considerable progress has been made towards describing jet noise since the pioneering work of Lighthill, the mechanism by which a jet flow generates sound remains to be found.
In order to devise physics-based solutions that might reduce the sound power radiated by propulsive jets, it is important to find the physical mechanism behind jet noise.
The objective of this project is to first develop a functional model of Lighthill's stress for both laminar and turbulent jets and identify what part of the model is responsible for sound generation. The mechanism by which sound is generated by that component will then be investigated.
(Image Source: Presentation - AIAA 2009 - Separating propagating and non-propagating dynamics in fluid-flow equations - Sinayoko, Agarwal, Hu)