Numerical 2D Air Flow Simulation over a Backward-Facing Step and a Block
This report demonstrates the application of the PHOENICS code to the analysis of two typical flow situations used in the study of recirculating flows, the 2-D backward-facing step flow and the 2-D (square) block flow. The findings are focused on the positions and lengths of the recirculating zones behind the step and block respectively. The results are compared with both experimental results and other numerical (TEACH) simualtions.
The results are competitive with the TEACH simulations referred to, without any streamline curvature corrections made to the standard k-ɛ model of turbulence. The agreement with experimental values are typically within -5%, in the worst case -24%, where small 3-D effects were reported.
The accuracy of the k-ɛ model is obscured by the numerical inaccuracy of the upwind differencing method, which also play its part in, the difficulty to get grid-independent solutions.
KeywordsRecirculation Zone Fine Mesh Coarse Mesh Turbulent Shear Flow Numerical Inaccuracy
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