The Linearized Theory of a Supercavitating Hydrofoil With a Jet Flap

Abstract

A theoretical analysis is carried out for the steady cavity flow about thin hydrofoil sections at small incidence α, at the trailing edge of which a thin jet emerges at a small deflection τ. The flow is assumed to be inviscid and incompressible and the cavitation number is taken to be zero. The jet is assumed so thin that it can be considered as a vortex sheet across which the velocity is discontinuous. For the case of a flat plate, expressions have been obtained for lift, drag, pressure distribution, pitching moment, the jet shape, and the cavity shape. Numerical calculations are made for a number of jet momentum-flux coefficients CJ lying between 0.01 and 5.