Flow Phenomena Resulting From A Compression-Bump Engine Air Intake

Abstract

Compression-bump engine air intakes play a major role in the development of new fighter aircraft, since due to their geometrical shape they contribute to the reduction of radar cross-section. In direct competition to Pitot air intakes, the compression bump shape has to be optimally designed in order to guarantee high total pressure recoveries by displacing the incoming boundary layer so far outwards that only high momentum flow enters the air intake channel and flow distortion is minimal. However, due to the fact that fighter aircraft cover a wide range of flight Mach numbers from sub- to supersonic flows, the physics of compression bump intake flows is complicated and not completely understood. In order to explain occurring flow phenomena and derive design rules for such types of intakes, the DLR has developed a compression bump intake for its future fighter demonstrator aircraft. Numerical simulation studies have been performed to investigate the diverse flow phenomena, preparing experiments which will be designed to gain flow data for validation.