For most air breathing engines, the incoming air needs to be slowed down before it can be directed into the compressor or combustor. This is accomplished using a diffuser, which is a duct designed to slow down incoming gas flow to a lower velocity. The incoming flow can either be subsonic or supersonic depending on the application.
In fact, diffusers are an integral part of supersonic wind tunnel design. In this lesson we will understand the vital role played by diffusers and how they make the overall wind tunnel design more efficient and economical to operate.
Here are the accompanying handout slides for this lesson.