ANALYSIS OF HYPERSONIC NOZZLES INCLUDING VIBRATIONAL NONEQUILIBRIUM AND INTERMOLECULAR FORCE EFFECTS

A computational fluid dynamics technique is developed for the study of high-pressure, axisymmetric hypersonic nozzle flows. The effects of i ntermolecular forces and vibrational nonequilibrium are included in th e analysis. The numerical simulation of gases with an arbitrary equati on of state is discussed. Simulations for high-pressure nitrogen nozzl es (p0 = 138 MPa) demonstrate that both intermolecular forces and vibr ational nonequilibrium affect the flow significantly. These nonideal e ffects tend to increase the Mach number at the nozzle exit plane. In a ddition, these effects may introduce weak expansion and compression wa ves in the nozzle that degrade test section now quality. Thus, they mu st be included in the design and analysis of high-pressure hypersonic nozzles.