Designing Air Intake Ducts for High Speed Flight

Abstract

A proven duct flow model is used to examine the influence of the intake duct geometric and inlet flow parameters on the pressure recovery performance of intake ducts for high speed flight. The geometric parameters include: the inlet parallel pipe length, the diffuser cone angle, the length of the faired transition from the pipe to diffuser cone as well as the degree of the fairing. The inlet flow parameters examined are: the boundary layer momentum thickness, the velocity profile shape and the turbulence level. The inlet parameter values used simulate those following a normal shock wave — turbulent boundary layer interaction inside the intake duct, i.e. they simulate the conditions at the inlet to the diffuser of a supersonic intake