Jet-Flat Plate Interaction: Wall Pressure Coherence Modeling

Abstract

In this paper the wall pressure fluctuations induced by a compressible jet overflowing a flat plate were analysed with the scope of providing an analytical prediction of the two-points coherence. The reported approach follows the idea formulated by Efimtsov to model the coherence at relatively high Mach numbers and with a good accuracy in the low wave-numbers region. The database used for the model assessment refers to an experimental campaign carried out into the semi-anechoic chamber of the Roma Tre University using pressure transducers flush mounted at the wall of a rigid flat plate. The jet Mach number was varied within the compressible subsonic regime up to 0.9 and two different nozzle exhaust diameters were considered to analyse the effect of the Reynolds number. The tangential flat plate was installed at 0.75 diameters from the jet axis, a position that reproduces well a realistic jet-wing configuration. The ability of the model to predict the coherence function is verified for the whole range of conditions investigated and the achieved results are discussed with reference to the available literature.