Parametric Study of a 1.5-D Combustion Chamber Model on the Hybrid Rocket Engine Performances

International audienceA sensitivity analysis of a 1.5-D combustion chamber model of a hybrid rocket engine is performed in this paper. The goal is to assess the impact that some of the most important engine parameters have over its performances. Studies are carried out by considering three categories of parameters: the aerodynamic characteristics at the inlet of the chamber, the thermochemical quantities involved in the gas-surface interaction model, and the geometrical properties of the fuel block. Simulations have been made at steady-state regime for a cylindrical, lab-scale combustion chamber with a 1-D nozzle model, using mainly gaseous oxygen as oxidizer and high density polyethylene as fuel. The fundamental reference variables used for the sensitivity studies have been the regression rate, the averaged chamber pressure, the radial profiles of temperature and species mass fractions, and the thrust and specific impulse of the engine. Fuel regression rate results have shown a high dependence upon the oxidizer mass flux, the motor size, the number of ports of the fuel block, and the variables intervening directly on the energy balance at the fuel surface, such as the radiative heat flux source and the composition of the solid fuel. The retrieved influence of these parameters on engine performances has been found to be in agreement with the literature data, being in some cases of the same intensity