Variational multiscale methods for turbulence control
Collis, S. Scott
Master of Science thesis
Large Eddy Simulation (LES) is an efficient computational tool for turbulence simulation. Variational Multiscale (VMS) is a new paradigm for LES that uses variational projection instead of spatial filtering that obviates many issues related to spatial filtering in traditional LES. VMS for a fully-developed turbulent channel flow using a constant coefficient Smagorinsky model is implemented in a hybrid-spectral code. Our implementation differs from prior VMS where we apply scale separation only in the homogeneous directions, i.e. in the planes. The results obtained are comparable to prior VMS implementations that show good agreement with Direct Numerical Simulation (DNS) and are superior to dynamic LES. The ability of the VMS method to simulate turbulence control is studied in the context of opposition control. The results show good agreement with DNS and dynamic LES making VMS an attractive method for turbulence control investigations.