TURBULENT 3D LID-DRIVEN CAVITY FLOW OF VISCOPLASTIC FLUIDS

Paulo Arthur Beck¹; Sérgio Frey¹; Horácio Antonio Vielmo¹

¹ UFRGS

doi:10.20906/CPS/COB-2015-0793

Resumo

The authors investigate the turbulent 3D lid-driven cavity flow of viscoplastic fluids, aiming to validate the application of the Reynolds Stress Transport turbulence model coupled with a regularized viscosity function. For that, the SMD viscosity function and the Navier-Stokes equations are solved together with the transport equations of the turbulence model. The Finite-Volume Method is used to approximate the resulting system of equations which are solved using the code STAR-CCM+. The analysis of the viscoplasticity and inertia effects uses dimensionless flow and rheological quantities, and the state of turbulence assessment relies on the mapping of the anisotropy of the Reynolds stresses. The combined effects of flow inertia and fluid rheology are discussed, and the state of turbulence and velocity profiles are determined for mildly and fully turbulent flows. Moreover, considerations are drawn concerning the applicability and stability of the numerical solution in the limiting case of substantial non-linearity of the viscosity function. The results demonstrate the rheology of the fluids markedly influences the state of turbulence, and the return-to-isotropy trajectories of the Reynolds stresses. In conclusion, the coupling of the Reynolds Stress Transport turbulence model and a regularized viscosity function produces consistent results from both rheological and turbulence perspectives.

Palavras-chave: viscoplastic fluids; SMD viscosity function; lid-driven cavity flow; turbulence