Modeling and Prediction of Acoustic Resonance for Round Supersonic Jets

A computationally rapid analysis tool has been developed to compute the acoustic resonance of off-design supersonic jets known as “screech”. For the case of round jets, the computational model is described which is based on coupling analytical representations of each of the four components of the resonance: 1) the shear layer instability; 2) the vortex/shock interaction; 3) the upstream-propagating acoustic radiation; and 4) the receptive coupling of scattered acoustic waves and instability waves at the nozzle lip. Comparisons among predicted and measured sound pressure levels and frequencies of the resonance are presented for a range of jet operating conditions.