Numerical Acoustic Prediction of a Quadratic Supersonic Jet Using CAA Hybrid Methods

Abstract

A numerical simulation of a rectangular supersonic nozzle was conducted to predict the acoustic emissions produced by the jet. The numerical results were compared with experimental measurements. The best agreement between the experiment and simulation was found within the lateral region of the jet. It is the deciding region of noise emission in the test facilities as it represents the gap between rocket nozzle exit and the guide tube inlet. The results were less satisfactory, for the microphone positions within the down-stream region of the jet, where the noise emissions are typically damped by water injection. The simulation under-predicted the overall sound pressure levels. The results confirm the expected limitations for the underlying model used in the simulation. The work is a first step to gain experience prior to simulating a subscale rocket engine in combination with and without a guide tube.