Jet Aeroacoustics

This study conducts a comprehensive high-fidelity simulation of a rectangular jet with a nozzle aspect ratio of 2, with a focus on investigating the jet noise control approach via nozzle-lip micro-jet excitation. The objective is to both examine the possible jet noise reduction in rectangular jets and to obtain insights into the alterations in the jet flow structures caused by the micro-jet that lead to the change in the far-field acoustic radiation. In particular, the study investigates the impact of various frequency excitation modes implemented through jet-axis-directed periodic fluidic injections at the nozzle lip. SPOD analysis is conducted to examine the corresponding modification of the dominant coherent jet structures and their correlation with the radiated noise spectrum.