Progress towards a model to describe jet/aerodynamic-surface interference effects

Abstract

A first generation model is presented which relates the pressure distribution on an aerodynamic surface to properties of the jet plume. The characteristics of a jet in a cross flow are of primary importance in determining the pressure distribution on the aerodynamic surface and are assumed to be (1) a pair of contrasting vortices associated with a jet in a crossflow, (2) entrainment of crossflow fluid into the jet plume, and (3) a wake region near the aerodynamic surface and extending downstream from the jet orifice. The model is applied to the configuration of a round jet exhausting perpendicularly through a flat plate into a uniform crossflow for a range of jet-to-crossflow velocity ratios from three to ten. It is demonstrated that the model is capable of describing the measured pressure distribution on the flat plate with model parameters that are compatable with the incomplete description of the vortex pair that is available. The fore and moments on one plate are presented as functions of jet-to-crossflow velocity ratios.