Analysis of Lift Augmentation of Vertical Solid Jets in Proximity of the Ground

Abstract

An analysis of the lift augmentation properties of a vertical solid two-dimensional subsonic jet due to the presence of the ground is presented. The jet efflux is assumed to behave as an ideal, inviscid fluid, and familiar potential flow techniques are used to solve the resultant problems. The factors controlling the phenomenon are height from the ground, nozzle wall angle, and compressibility. The results in the form of curves of lift augmentation against height from ground show that, whereas the effects of compressibility are very small, the effect of nozzle wall angle is important and can be a useful design-control parameter.