Compressible Flow Regimes — Lesson 4

It might sound boring to spend about five to six hours on an airplane flying from New York to Los Angeles. However, the large jetliners are currently the fastest transport vehicles operated commercially in the world. Their cruise speed can exceed Mach 0.8, which falls into the transonic flow regime. But, can we travel even faster than that?

The answer is yes. In fact there used to be two supersonic airliners operated commercially in the last century. The Concorde was one of the two and its maximum speed was over twice of the speed of sound. Well, how about going faster than a supersonic airplane?

A hypersonic vehicle such as a rocket can fly much faster than the speed of sound, but none is commercially feasible yet.

So how do we know whether an object or a flow is transonic, supersonic, hypersonic or something else? This lesson will answer that question. Furthermore, we will introduce in total five flow regimes categorized by the Mach number. We will also go through the flow features and characteristics of each flow regime in detail.

Alternate video link.

Here are the accompanying handout slides for this lesson.