An
intake ramp is a rectangular, plate-like device within the
air intake of a
jet engine, designed to generate a
shock wave to aid the inlet compression process at
supersonic speeds. 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 an oblique shock wave at the forward end of the ramp. Air crossing the shock wave suddenly slows to a lower
Mach number, thus increasing
pressure.