Study of total pressure losses at the engine face of a submerged inlet with an ingested vortex

Abstract

An experimental study of the effect of vortex ingestion into an S-duct diffuser on flow conditions at the engine face is presented. A simultaneous ingestion of a boundary layer is also considered. In order to form a boundary layer of well-defined thickness ahead of the intake the diffuser is arranged on a flat plate. The dependence of the circulation of the ingested vortex on the flow in the diffuser has been examined in a parametric study in a blow-down wind tunnel. The free-stream Mach number was varied between M = 0.30 and M = 0.65 at a fixed mass flow. In the introduction the importance of boundary layer ingesting highly integrated intakes is briefly discussed. This is followed by a description of the analytical design of the generic intake model, the cryogenic blowdown tunnel DNW-KRG in which the experimental tests have been performed, and the measurement techniques. Thereafter, experimental findings are discussed in detail and conclusions are drawn.