Recently, a novel test bench was developed at the Bundeswehr University of Munich in order to study secondary near-wall reactions caused by cold injection of methane into an oxygen-rich hot crossflow. The available measurements of the experiment, namely Laser Induced Fluorescence (LIF) of OH allowed to locate the reaction zone and to estimate the autoignition length, while the heat load prediction at the wall was calculated from the thermocouple readings using the inverse heat transfer method. A numerical investigation of this test bench is presented in this work. In the first part, non-reactive Large Eddy Simulations (LES) are used to evaluate the turbulent boundary conditions of the reactive test rig. The use of LES provides an insight in the distribution of velocity, turbulence intensity, temperature and species within the hot flow generator (burner), the fuel injection nozzles and the inlet of the reactive test rig. In the second part, reactive LES computations are used for comparison of the autoignition length and the wall heat fluxes with the experimental data, based on the boundary conditions provided by the non-reactive LES. The results show that in this configuration the autoignition length is more strongly affected by the hot gas inlet temperature than by the turbulent fluctuations of the crossflow. The qualitative comparison with the autoignition length assessed from the experiment is satisfactory and a wall heat flux distribution similar to the experimental distribution is obtained downstream the fuel injection nozzles.    «

Recently, a novel test bench was developed at the Bundeswehr University of Munich in order to study secondary near-wall reactions caused by cold injection of methane into an oxygen-rich hot crossflow. The available measurements of the experiment, namely Laser Induced Fluorescence (LIF) of OH allowed to locate the reaction zone and to estimate the autoignition length, while the heat load prediction at the wall was calculated from the thermocouple readings using the inverse heat transfer method. A...    »