Toufik Zebbiche
International Journal of Aeronautical and Space Sicences, vol. 9, no. 1, pp.1-30, 2008

Abstract : When the stagnation temperature of a perfect gas increases, the specific heats and their ratio do not remain constant any more and start to vary with this temperature. The gas remains perfect; its state equation remains always valid, except, it is named in more by calorically imperfect gas. The aim of this work is to trace the profiles of the supersonic axisymmetric Minimum Length Nozzle to have a uniform and parallel flow at the exit section, when the stagnation temperature is taken into account, lower than the dissociation threshold of the molecules, and to have for each exit Mach number and stagnation temperature shape of nozzle. The method of characteristics is used with the algorithm of the second order finite differences method. The form of the nozzle has a point of deflection and an initial angle of expansion. The comparison is made with the calorically perfect gas. The application is for air.

Keyword : Axisymmetric Minimum Length Nozzle, Prandtl Meyer Function, High Temperature, Numerical Integration, Finite Differences Method, Predictor Corrector Algorithm, Interpolation, Stretching Function, Straight Sonic Line, Calorically Imperfect Gas, Pressure Force, Mass of Nozzle, Relative Error