Receptivity analysis in under-expanded supersonic impinging jets

Abstract

This paper presents the receptivity process at the nozzle-lip to an external forcing in the configuration of under-expanded supersonic impinging jets. The nozzle-lip is considered as a linear transformer. Therefore, the linearised three-dimensional Navier Stokes equations in cylindrical coordinate are considered. The mean flow fields are obtained from large-eddy simulations. An impulse response analysis of the linearised system is performed which allows a wide range of frequencies to be excited. The transfer function at the nozzle-lip is used to characterise the receptivity process. The sensitivity of the transfer function to the pulse location and the azimuthal wave number is performed. It ..