Experimental study on effects of plate angle on acoustic waves from supersonic impinging jets.

This study experimentally investigates the generation mechanism of a higher-angle lobe which is an acoustic field feature of a supersonic jet impinging on an inclined flat plate. The overall sound pressure level distribution and spectra, the conditional averages of near field schlieren movies, and the time-averaged wall pressure distribution were obtained for three cases of Mach 1.8 ideally expanded impinging jets with plate angles of 45°, 22.

Data-educed broadband equivalent acoustic source model for supersonic jet noise.

A broadband equivalent acoustic source distribution can be used to model the sound field near a high-speed jet. Such models must account for the spatiospectral variation of the sound levels. This work presents a technique for obtaining such a model using a spectral decomposition method associated with large and fine-scale turbulent mixing noise to create broadband equivalent source distributions for each noise type.

Conditional sampling analysis of high-speed schlieren movies of Mach wave radiation in a supersonic jet.

Acoustic-triggered conditional sampling analysis can extract the broadband-noise-related intermittent fluctuations from complicated schlieren visualization movies around the source region, which is difficult when using conventional methods. In this study, an analysis of the Mach wave radiation from a supersonic jet was performed. The extracted results properly captured the known features of the Mach waves and their sources (i.