Numerical and experimental investigations of geometrical parameters on GH2/GO2 injector

Abstract

To study the influence of injector geometrical parameters on combustor flow fields, detailed numerical and experimental investigations of a single-element injector with gaseous hydrogen and gaseous oxygen (GH2/GO2) propellants were performed at atmospheric pressure. The flow field characteristics of three different injector forms: shear-coaxial, swirl-coaxial and dual-swirl were discussed. The simulations of the combustion process with the use of steady Reynolds-averaged Navier-Stokes (RANS) techniques on a base of the ANSYS software were conducted. The Realizable k-ε turbulence model and eddy-dissipation concept combustion model were employed taking into account reactions of chemical kinetics. Results from the simulations demonstrated the detailed flame structures of the combustion flow fields. Subsequently, an advanced, non-intrusive optical diagnostics approach was adopted, including high-speed imaging and OH* chemiluminescence. The results show that the swirl flow injector approach elicits a distinctly different ignition process, in which the heat load from the swirl flow results in substantial damage to the chamber wall. Finally, with the help of advanced imaging processing method, it verified the validation of the numerical simulated model and acquired a specific linear relationship between the optical data and numerical calculations.