Numerical Analysis of Laser Ignition and Flame Development in a Subscale Combustion Chamber

Abstract

Methane has never been used as rocket fuel in a flight mission up to now. However, for upper stage engines and long duration scientific missions it can provide beneficial properties compared to the commonly used fuels. Reliable ignition is crucial for the usage of a rocket engine, especially for mission scenarios requiring ignitions at space conditions. Thus, for future use of methane as rocket fuel, detailed knowledge about the flame behavior in methane/oxygen mixtures inside rocket combustion chambers is essential. The goal of this work is to simulate the laser ignition of methane/oxygen-mixtures in an experimental combustion chamber and gain insight in the processes occurring during the ignition phase. Simulations are done using Unsteady Reynolds-averaged Navier-Stokes (URANS) equations. Combustion is modeled using the combined Finite Rate Chemistry/Eddy Dissipation Model (FRC/EDM) and a reduced global four-step chemical reaction mechanism. Simulations are done using a simplified 180°- and the full 3D-geometry of the combustion chamber and injector. The results show sensitivity towards the time of ignition and the geometry used in the simulation.