Large-Eddy Simulation of Flame-Turbulence Interactions in a Shear Coaxial Injector

Abstract

Various state-of-the-art Computational Fluid Dynamics (CFD) approaches are currently being evaluated by NASA for the modeling of combustion chambers in liquid rocket engines. This evaluation is performed through the simulation of a laboratory-scale chamber equipped with a single-element gaseous hydrogen-gaseous oxygen GH2-GO2 shear-coaxial injector. While a joint paper 1 compares the dierent steady and unsteady simulations of this chamber, this paper focuses on the three-dimensional Large Eddy Simulations (LES) performed at the Georgia Institute of Technology. The goal here is to nd a compromise between accuracy and computational cost while accurately capturing the unsteady ame physics thanks to the full 3D formulation. The solver employed in this study includes a hybrid central-upwind scheme used to solve the compressible, multi-species Navier-Stokes equations with a thermally perfect formulation. From a resolution point of view, priority was given to the near-eld resolution rather than the near-wall resolution. Yet, the seemingly correct modeling of the ame anchoring and dynamics provides a satisfactory estimate of the wall heat ux. The unsteady and three dimensional features of the ow are discussed in length and the implications of the unique features of this shear-coaxial GH2-GO2 injector for turbulent combustion modeling are also analyzed.