supersonic diffuser

supersonic diffuser

[¦sü·pər¦sän·ik di′fyü·zər] (mechanical engineering) A diffuser designed to reduce the velocity and to increase the pressure of fluid moving at supersonic velocities.

supersonic diffuser

A diffuser designed to reduce the velocity and increase the pressure of fluid moving at supersonic velocities. Air enters at a velocity greater than the speed of sound, is decelerated in a contracting section, and reaches sonic speed at the throat. Supersonic compression systems can be classified into three basic types:
i. External-compression inlets have the supersonic diffusion taking place at or ahead of the cowl lip or throat station and generally employ one or more oblique shock waves ahead of the normal shock.
ii. Internal-compression inlets accomplish supersonic diffusion internally downstream of the cowl lip. Deceleration of the flow is produced by a number of weak reflecting waves in a gradually convergent channel.
iii. A combination of external and internal compression, it is an effective compromise. It generally employs one or more oblique shock waves ahead of the normal shock.