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

摘要

The turbulent combustion inside the main chamber of a liquid rocket engine is difficult to numerically model because of the wide range of scales involved, the complex thermodynamics at elevated pressure, and the influence of heat transfer. Here, a single-element gaseous-hydrogen-gaseous-oxygen shear-coaxial injector is studied. This case involves complex physical processes that are simulated using a large-eddy simulation approach. In particular, modeling of the nonpremixed turbulent combustion and its impact on the wall heat flux is addressed. This large-eddy simulation of the compressible multispecies Navier-Stokes equations is solved using a hybrid central-upwind scheme with a thermally perfect formulation. To keep the computational cost reasonable, priority was given to the near-field resolution over the near-wall resolution. The modeled flame anchoring and dynamics provide a satisfactory estimate of the wall heat flux. The unsteady and three-dimensional features of the flow are discussed in length, and the implications of the unique features of this shear-coaxial GH_2-GO_2 injector for turbulent combustion modeling are analyzed.