Prediction of Boundary-Layer Flow Separation in V/STOL Engine Inlets

Abstract

The paper provides a theoretical description of the development of the boundary layer on the lip and diffuser surface of a subsonic inlet at arbitrary operating conditions of mass flow rate, freestream velocity, and incident angle. Both laminar separation on the lip and turbulent separation in the diffuser are discussed. The agreement of the theoretical results with model experimental data illustrates the capability of the theory to predict separation location. The effects of throat Mach number, inlet size, and surface roughness on boundary-layer development and separation are illustrated.