Computational Fluid Dynamics Laboratory

DNS/LES of Homogeneous Turbulence

We have conducted 3D DNS and LES of homogeneous turbulence to explore new SGS turbulence models. The code solves the incompressible Navier-Stokes equations using a traditional Fourier pseudospectral method featuring dealiasing by either the 3/2 rule or the phase shift rule. The code uses a unique parallel 3D FFT library that has allowed for scaling on up to 16,000 processors of the IBM BG/L at IBM's Watson's Laboratory. LES of the high-Reynolds number expermiental dataset from Kang et al. (2003) has been conducted. The focus is on the use of regularization based models and most recently the so-called t-model. Two publications have appeard in the Journal of Turbulence and SIAM's Multiscale, Modeling and Simulation (see paper list for exact reference). The code also features various forcing strategies and scalar mixing to study SGS mixing models.

Below are baseline TKE results showing LES with Smagorinsky model compared to the experimental data of Kang et al. (2003). LES vs. Experiments (Kang et al.)

Below is sample from LES of Taylor-Green vortex. Scroll down for all images. LES of Taylor-Green Vortex

LES of Taylor-Green Vortex

LES of Taylor-Green Vortex