SUBSONIC TO SUPERSONIC NOZZLE FLOWS

Steady, irrotational flow of a compressible fluid through a two-dimensional planar and axisymmetric nozzle is formulated and solved numerically in the hodograph or velocity plane. The Legendre potential is used to express the governing equation which for planar flow is linear and for axisymmetric flow nonlinear. The hodograph transformation method is extended to solve the nozzle problem for supersonic flow. A rectangular numerical domain for the supersonic case results from the way the information travels in the region that is the image of the flow that occurs around the lip of the nozzle surface. Knowledge of the characteristic's exact location in the supercritical region of the domain is not required, but only the general direction in which information propagates.