Large Eddy Simulation of Supercritical Mixing and Combustion for Rocket Applications

We report on the implementation of the real fluid capabilities to CharlesX, the in-house, unstructured, large eddy simulation code used at the Center for Turbulence Research at Stanford University. A conceptually distinct implementation was needed for the puremixing and the flamelet/progress-variable (FPV) model combustion case. For the nonreacting simulations, a Newton-Raphson based iterative algorithm is used to determine the temperature from the transported density and energy. For the reacting simulations, an extended flamelet table is used that tabulates the departure functions as well as the compressibility factor. These tabulated parameters are used to correct the transported thermodynamic properties. The real fluid extension to CharlesX was used to investigate a non-reacting and a reacting case. In both of these cases, a second-order essentially nonoscillatory (ENO) schemes is locally applied to the flux computation on the faces identified with a dual-threshold relative density sensor. This avoids spurious oscillations of the numerical solution with limited numerical dissipation. This preliminary work illustrates the capability CharlesX to capture the important physics in a typical rocket engine configuration.