Study of the Coupling Between Twin Single Beveled Supersonic Jets Using Linear and Non-Linear Spectral Analysis Techniques

摘要

Twin jets emanating from closely spaced nozzles can interact quite unpredictably and give rise to high dynamic pressures in the internozzle region which can result in sonic fatigue of sensitive aircraft equipment. This project studies the interaction between two such jet from nozzles having a single beveled exit geometry. Such nozzles are finding increasing use in modern aircraft due to the thrust vectoring and performance advantages they present. The study begins by using traditional linear spectral analysis techniques to study the coupling mechanism. It goes on to reveal the limitations of such linear techniques for understanding phenomena that are as complex as the one studied in this project and uses non-linear techniques to uncover results that have hitherto gone unreported. It is hoped that the results of these techniques will be of use to nozzle designers as well as to scientists involved in the field of numerical simulation of jet noise so as to provide benchmark data for the validation of their models.