Characterization of the flow-field in circular subsonic impinging jets

Abstract

Impinging jets are relevant ow configurations in many technological developments. For example, on some short take-off and landing aircraft the high speed exhaust from the jet engine is deflected by direct impingement on the aps to create extra lift during take-off. Fatigue due to excessive dynamic loading on the aps and high levels of noise radiation are among the problems encountered in such designs. Additionally, such flow-structure interaction is a good model for cooling of turbine blades, annealing of plastic and metal sheets, deicing of aircraft systems etc.. Jets are easy to simulate and contain all the constituents necessary for the study of shear flows. The shear-layer instability at the nozzle edge develops into axisymmetric toroidal vortices which magnifies in size and strength downstream of the nozzle. The interaction of these vortices with the solid structures induces pressure fluctuations that manifests in the form of noise in the far-field region. Hence, it is also a benchmark case for studying vortex-structure interaction noise.