Turbulence for Non-Newtonian Fluid Flows

Fundamental research on turbulent flows of non-Newtonian fluids, especially those that exhibit elastic effects, including turbulence models development. Our research on turbulence is based on the FENE-P constitutive equation and uses DNS data for understanding the mechanisms of turbulence as well as for a priori and a-posteriori turbulent model development. We have developed turbulence models for channel flow based on the Reynolds-averaged Navier-Stokes concept for FENE-P fluids, and more recently we have started to investigate in depth the physics of forced homogeneous isotropic turbulence (HIT) of viscoelastic fluids, identifying the polymer induced energy cascade. Based on the DNS of HIT we have also developed the dynamic similarity model for the sub-grid scale contribution to the polymer stretching in the evolution equation for the filtered conformation tensor, i.e., for the prediction of HIT in the context of Large Eddy Simulation (LES) models of viscoelastic flows. Currently we are investigating the development of new LES closures for inhomogeneous turbulent flows, starting with the planar jet and subsequently with the channel flow.

The research on this topic has been carried out in collaboration with Prof. BA Younis at University of California, Davis, Professor R. Sureshkumar at Washington University in St. Louis, Dr. Kyoungyoun Kim at Hanbat National University in Korea, Dr. Carlos Betancourt da Silva at Instituto Superior Técnico and Dr. Daniel Cruz at Universidade Federal do Rio de Janeiro, Brazil.