High temperature gas effect on the Prandtl-Meyer function with application for supersonic nozzle design

¹ Department of Mechanical Engineering, Faculty of Technology, University of Blida 1, BP 270, 09000 Blida, Algeria
² Institute of Aeronautics and Space Studies, University of Blida 1, BP 270, 09000 Blida, Algeria
³ Aircraft Laboratory, Institute of Aeronautics and Space Studies, University of Blida 1, BP 270, 09000 Blida, Algeria

^a Corresponding author : z_toufik270169@yahoo.fr

Received: 24 December 2015
Accepted: 30 April 2016

Abstract

This work is to develop a new computational program to determine the effect of using gas propellant of the combustion chamber at high temperature on the calculation of the value of the Prandtl Meyer function and application to supersonic nozzles design. The selected gases are the H₂, O₂, N₂, CO, CO₂, H₂O, NH₃, CH₄ and air. Prandtl Meyer function depends on the stagnation temperature, Mach number and the gas used. The specific heat at constant pressure and the enthalpy of the gases vary with the temperature and the selected gas. The gas is still considered as perfect and it will be calorically imperfect and thermally perfect below the threshold of dissociation of molecules. A calculation of the difference between the Prandtl Meyer function for different gases with the air is made for the purpose of comparison. The application is made for designing the supersonic MLN nozzle at high temperature.