SUPERSONIC EXTERNAL-COMPRESSION DIFFUSER AND METHOD FOR DESIGNING SAME

摘要

A supersonicexternal-compression inlet (20)comprises a generally scoop-shapedsupersonic compression sectionfor diffusing a supersonic freestream flow (24). The supersoniccompression section includes a mainwall having a leading edge (28) anda throat portion downstream of theleading edge (28), and side portionsjoined to opposite side edges of themain wall so as to form a generallyscoop-shaped structure. The sideportions advantageously extend intothe supersonic flow stream far enoughto encompass the initial oblique shock wave that is attached to the leadingedge of the main wall. The main wall has an inner surface(22) formed generally as an angular sector of a surface of revolution, theinner surface (22) of the main wall coacting with innersurfaces of the side portions to define a three-dimensional external-compression surface. The supersonic external-compression inlet(20) also includes a subsonic diffuser section arranged to receive flow fromthe supersonic compression section and to diffuse theflow to a subsonic condition. A variable-geometry inlet includes an externalramp hinged about its forward edge and forming aportion of the inner surface of the scoop-shaped diffuser, pivotal movement ofthe external ramp serving to vary a throat size of theinlet. The subsonic diffuser (20) includes an internal ramp hinged about itsaft edge for maintaining a smooth transition from theexternal ramp.