Flow past circular cylinder(s) in turbulent regime

N. Jalaiah

Hi

I am trying to simulate the flow past circular cylinder(s) at high Reynolds numbers (in the order of 10^4 to 10^5) using FLUENT 5 software. This regime is of interest in practical heat exchangers. The computational domain was discretized using hybrid mesh, i.e., quadrilateral cells around the cylinder and triangular cells in the rest of the domain using GAMBIT. The numerical simulation was made for unsteady, 2D case using LES as the turbulence model with Smagorinsky-Lilly subgrid model. The pressure coefficient recovered excessively at the rear of the cylinder. The experimental results show 10 to 15% recovery while the present analysis recovers almost to 45%. The separation point is also later than seen in experiments. I believe that this is because of inadequate accounting of turbulent viscosity in the model used.

Literature has references to simulation of flows at lower Re values. Predictions of Strouhal numbers seem to come out alright. However, the devil seems to be in the pressure distribution.

Have you worked on this problem? Do you have suggestions that I might find useful? Your contribution to my work will be gratefully acknowledged in my thesis and references and all the papers that will be published out of this work.

I can send the grid and pressure distribution results if you like. My email id is : jalaiah@hotmail.com

Thanks. Jalaiah.