Wavepacket models for supersonic jet noise

Wavepacket models for supersonic jet noise

Gudmundsson and Colonius (J. Fluid Mech., vol. 689, 2011, pp. 97–128) have recently shown that the average evolution of low-frequency, low-azimuthal modal large-scale structures in the near field of subsonic jets are remarkably well predicted as linear instability waves of the turbulent mean flow using parabolized stability equations. In this work, we extend this modelling technique to an isoth...

Wavepacket Modeling of the Jet Noise Source

This research is motivated by the need for physical models for the jet noise source to be used in practical noise prediction schemes for propulsion-airframe integration concepts. The emphasis is on jets with high-subsonic velocities typical of modern turbofan engines. The basis for the source model is an amplitude-modulated traveling wave the wavepacket. Its parameters are determined by minimiz...

Summary of "Supersonic Jet and Rocket Noise"

Mach Wave Noise of a Supersonic Jet

Supersonic jets emit noise to the outside in form of Mach waves which are long, straight and have about equal angles. Experiments done by Oertel sen. visualized clearly these Mach waves and he publicized moreover that such Mach waves exist also inside the jet. Experimental and theoretical studies in the past did not allow a complete understanding of the phenomenon up to now, wherefore the need ...

Simulation of Supersonic Military Aircraft Jet Noise

Background: There is a growing need to reduce significantly the noise generated by high-performance, supersonic military aircraft. The noise generated during takeoff and landing on aircraft carriers has direct impact on shipboard health and safety issues. Also, noise complaints are increasing as communities move closer to military bases or when there are changes due to base closures and realign...