Question

Diffuser is only applicable for incoming subsonic flow.

(a) True

(b) False

I have been asked this question during an interview for a job.

My question is from Compressible Flow through Diffusers in division Compressible Flow through Nozzles, Diffusers and Wind Tunnels of Aerodynamics

Answer 1

Right option is (b) False

To elaborate: Diffusers work for both subsonic and supersonic incoming flows. Although the design and shape of diffuser in both the cases vary. In both the cases, the work of the diffuser is to lower the speeds by least total pressure reduction.