MULTI-PHYSICS MODELING PSAAP Center, Stanford University V. Terrapon, R. Pecnik, J. Larsson, B. Morgan, A. Irvine, F. Ham, I. Boyd, G. Iaccarino, H. Pitsch, S. Lele, P. Moin Acknowledgments This work was supported by the United States Department of Energy under the Predictive Science Academic Alliance Program (PSAAP) at Stanford University Unfueled combustor Fueled combustor Isolator bottom wall / side wall corner, pressure contour plot indicates induced bow shocks Pressure contour of bow shock at forebody leading edge H2 injectors, wall streak lines and pressure contours of scramjet combustor Mach 7.4 Pressure contour plots for unfueled and fueled combustor of the Hyshot II scramjet simulation Full-system simulation Shock-turbulence interactionComplex physical phenomena are involvedInjection, mixing and combustion Radiation Work performed by R. Pecnik and V. Terrapon Forebody RampInlet/IsolatorCombustor Nozzle/Afterbody Fuel Injection Bow Shock Shock Train (M ~ 2.5) Mixing and combustion (M > 1) Flow Mach ~8 Laminar/Turbulent Boundary Layer Turbulent Boundary Layer Heat Losses Heat Losses Canonical shock/turbulence interaction Isotropic turbulence passing through a nominally normal shock wave. The figure shows the shock as a transparent sheet and eddies colored by the vorticity magnitude. Note the increased vorticity, decreased size, and predominant alignment in the shock-plane of the post-shock eddies. Motivation and objectives Drastic changes in structure and statistics of turbulence and in shock structure Need to elucidate underlying physics and dynamics, and to devise novel and more physics- based turbulence models Approach DNS simulation of interaction between isotropic turbulence and shock Solution-adaptive high-order central/WENO method with minimal numerical dissipation Run on up to 65,536 cores on the BG/P machine Shock / turbulent boundary layer interaction Full system RANS simulation Cold: 3D with side walls, Spalart-Allmaras Hot: FPVA with H2 injection, no side walls, Spalart-Allmaras Motivation and objectives Oblique shock/boundary layer interaction common in scramjet shock train Limits scramjet inlet/isolator operability Difficult to predict using RANS Need to quantify modeling errors and develop improved reduced order models. Approach LES of oblique shock/boundary layer interaction High-order compact differencing scheme Localized Artificial Diffusivity (LAD) for shock capturing with dilatation-based switching function Rescale/Reintroduction with spanwise shifting used to generate inflow BCs Work performed by J. Larsson Work performed by B. Morgan LES of SWTBLI: contours of instantaneous density gradient magnitude at half span and instantaneous streamwise velocity contours near the wall (y/δ = 0.05, y + = 24) LES of SWTBLI: turbulent structures visualized by the second invarient of the velocity gradient tensor (Q) and colored by the streamwise vorticity Temperature in [K] Water mass fraction (progress variable) OH mass fraction Comparison with DLR HyShot II ground experiment: normalized pressure along the inside walls at the symmetry plane of the unfueled and fueled sides, pressure normalized by the static pressure at the isolator/combustor inlet. Fueled side Unfueled side inside walls Flamelet-based combustion model Motivation and objectives Heat release model is critical to accurately predict unstart by thermal choking Approach Flamelet-based approach with tabulated chemistry Temperature computed from energy and not looked up from table 3 additional transport equation for mixture fraction and progress variable Accurate chemistry mechanism (improved GRI-3.0) RANS simulation of the DLR HyShot II ground experiment: contours along combustor bottom wall, along symmetry planes and at different cross- sections. Mass flow rate of H 2 injected corresponds to an equivalence ratio of ϕ =0.3. Motivation and objectives Quantify uncertainty in wall heating of combustor/nozzle from Radiative Thermal Transport (RTT) Approach RTT code using implicit MC method Spectral modeling of hydrogen scramjet species Comparison of spectral code with Nelson results (J. Thermophysics and Heat Transfer, Vol. 11, 1997) for model combustor at M=14. Emitting species are H 2 O and OH. Work performed by V. Terrapon Work performed by A. Irvine Comparison of Monte Carlo RTT code with Fleck and Cummings results (J. Comp. Phys. Vol. 8, 1971) for cold slab heated by a blackbody.