ABSTRACT
Although no ideal fluid exists, many real fluid flows have small viscosity and the effects of compressibility are negligible. When the boundary layer regions remain thin, the non-viscous fluid results may be applied to real fluid flow motion to a satisfactory degree of approximation. Applications include the motion of a solid through an ideal fluid which is applicable with slight modification to the motion of an aircraft through the air, of a submarine through the oceans, flow through the passages of a pump or compressor, or over the crest of a dam, and some geophysical flows.
