Aerodynamic Design and Analysis of a Diverterless Compression Bump Engine Air Intake for Supersonic Aircraft Configurations by Means of CFD

Abstract

This report investigates the characteristic fluid mechanical phenomena occurring on a diverterless compression bump engine air intake for supersonic aircraft configurations. In order to obtain a test model of this novel type of engine air intake and use it to study and evaluate the suitability of the bump as the compression surface in the intake opening and its capability to substitute the boundary layer diverter and bleed systems, a CAD intake model was created using as a baseline analytical bump surface descriptions and intake design guidelines previously published. By means of numerical CFD simulations the fluid mechanical phenomena in the environment of the model’s intake opening and inside the intake duct are analysed and the success of conical pre-compression and effective boundary layer diversion not requiring separate diverter or bleed systems is demonstrated and explained on the basis of the CFD results. In studying varied geometries and flow conditions, aerodynamically sensitive design properties of bump and duct are identified, such as the longitudinal location of the bump’s upwind inflexion curve and the synergy of bump and duct. A process of iteration of CFD simulation and geometry adaptation led to an improved intake model with respect to its effectiveness in boundary layer diversion, overall pressure recovery and distortion at the engine face. Design guidelines for DSI designs are drawn and suggestions made for future research reusing the parametrically adjustable CAD model and CFD setup developed.