ABSTRACT
This chapter deals with some steady two-dimensional and threedimensional flow problems, both supersonic and subsonic. The governing equations are first established for irrotational motion, and then solutions to these equations are sought. The Janzen-Rayleigh expansion is discussed first. This expansion is a parameter expansion inpowers oftheMach number squared, and so it is valid only for Mach numbers somewhat less than unity. Small-perturbation theory is next discussed. This approximation assumes that the body about which the flow is sought disturbs the free stream in a minor way only. Since many real flow situations satisfy this condition, smallperturbation theory is widely used.
