ABSTRACT
The conditions under which noncontinuum effects become important and the nature of the changes in the flow produced by these effects is the subject of this chapter. Noncontinuum effects can have an important influence on the flow over craft operating at high altitudes at high Mach numbers. They can also have an important influence on the flow in high vacuum systems. However, because this book is intended to give a broad introduction to compressible fluid flows, no more than a very brief introduction to the topic of noncontinuum effects will be given here despite their significant practical importance in a number of situations.
