Patent ID: 7967241

Claim:
A supersonic aircraft jet engine installation having engine inlet structure, comprising a″) an inlet ramp and a cowl lip spaced outwardly of the ramp so that entering air flows between the ramp and lip, b″) the lip and ramp configured to produce a first oblique shock that extends outwardly from a forward portion of the ramp to pass ahead of the lip, and a terminal shock that extends outwardly from a rearward portion of the ramp to one of the following x o ) a region just ahead of the lip x l ) substantially to said lip, c″) and wherein the ramp in an axial radial plane or planes has a first portion of relatively slight concavity configured to produce an initial shock system that extends from the said first portion generally forward of the said lip and within the flow path of air through the inlet structure, said ramp having a second and intermediate section that is relatively straight and located rearwardly of said ramp first portion, and configured to produce substantially constant Mach number flow, and followed in the flow direction by a third section of relatively shallow concavity configured to produce an additional and oblique shock system that extends from the said third section such that the additional shock system intercepts the said terminal shock at a position within the incoming air captured between the ramp system and said lip, said third section followed by an additional and fourth relatively straight section configured so as to produce a generally constant Mach number associated with the air proceeding through the middle portion of the inlet structure, and including a fifth section providing initial turning of the flow towards the engine ahead of the terminal shock, said fifth section extending uninterruptedly from said fourth section, said inlet system characterized as creating a compression and shock system and total pressure distribution that is intentionally non uniform across any axial plane located rearwardly of the terminal shock.