Basic Facts
Ethirajan Rathakrishnan · 2019
Gas dynamics is the science of fluid flow in which both density and temperature changes become significant. Compressible flow is the science of fluid flow where the density change associated with pressure change is significant. Fluid mechanics is the science of fluid flow in which the temperature changes associated with the flow are insignificant. In general, the flow of an incompressible medium is called incompressible flow and that of a compressible medium is called compressible flow. A sound wave is a weak compression wave across which only infinitesimal changes in flow properties occur, that is across these waves there will be only infinitesimal pressure variations. The velocity of sound is used as the limiting value for differentiating the subsonic flow from the supersonic flow. The compressible flow regime can be subdivided into different zones based on the local flow velocity and the local speed of sound.