Intake ramp

An intake ramp (or inlet ramp U.S.) is a rectangular, plate-like device within the air intake of a jet engine, designed to generate a number of shock waves to aid the inlet compression process at supersonic speeds; such intakes are also referred to as two dimensional (2-D). The ramp sits at an acute angle to deflect the intake air from the longitudinal direction. At supersonic flight speeds, the deflection of the air stream creates a number of oblique shock waves at each change of gradient along at the ramp. Air crossing each shock wave suddenly slows to a lower Mach number, thus increasing pressure. The intake ramp for 2-D rectangular intakes has its equivalent in the inlet cone for circular/axisymmetric intakes.