Effect of turbulent transport models and grid spacing on pans calculations of a lid-driven cavity

Effect of Turbulent Transport Models and Grid Spacing on PANS Calculations of a Lid-Driven Cavity. (August 2004) Aditya Murthi, B. En., Amrita Institute of Technology and Science Chair of Advisory Committee: Dr. Sharath S. Girimaji The three-dimensional lid-driven cavity flow is investigated at Reynolds Number (Re)=10,000 for a wide range of spanwise aspect-ratios of 3:1:1,1:1:1 and 0.5:1:1, using the PANS (Partially Averaged Navier-Stokes) turbulence closure model. The PANS method is a variable resolution turbulence closure model, where the unresolvedto-total ratios of kinetic energy (fk) and dissipation (f2), serve as resolution control parameters. This study focuses on two main aspects of the PANS: first, the evaluation of Turbulent Transport models and second, the effect of grid spacing on accuracy of the numerical solution. The PANS calculations are tested against the LES and experimental results of Jordan (1994), in terms of both qualitative and quantitative quantities. The main conclusions are: (i) for a given fk value, the Zero-Transport (ZT) model is superior to the Maximum-Transport (MT) model for unresolved dissipation 2u, (ii) both the ZT and the MT models are adequate for unresolved kinetic energy Ku and, (iii) for a given grid size, the results depend heavily on grid spacing especially for larger fk values.