Akademik Veri Yönetim Sistemi
7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011, Ottawa, Kanada, 28 - 31 Temmuz 2011, cilt.2011-July, ss.1-6, (Tam Metin Bildiri)
This work presents a numerical study designed to address the 4th and 9th questions posed by S. B. Pope (New Journal of Physics, 2004) on the relative merits of physical and numerical (implicit) Large Eddy Simulation (LES and MILES) for high-speed, non-reacting and reacting air/H2 jets representative of scramjet engines. Simulations are performed at grid resolutions ranging from 32 x 32 x 128 to 256 x 256 x 1024 using a 5th order WENO scheme. Physical LES is conducted using the Smagorinsky and Selective Structure Function subgrid-scale models with molecular diffusion. Implicit LES is performed both with and without molecular diffusion. In the non-reacting case, the Smagorinsky model is overly dissipative, even with a low model constant (Cs = 0.1). The Selective Structure Function model gives better results, but does not show clear superiority over MILES at any of the grid resolutions considered. In the reacting case, a molecular viscous cutoff is required to impose a physical thickness for the reaction zone in MILES-Euler and to achieve grid convergence.