Numerical prediction of turbulent flow past a 2D surface-mounted rib

A numerical study was performed for investigating the turbulent flow over a surface-mounted two-dimensional rib using Hybrid Finite Analytic Method (HFAM). The Boussinesq approximation had been used for modeling of the Reynolds stress. A two-equation k-ε model with two-layer model was employed. The validity of the numerical method was tested by comparison the numerical predictions with experimental results and numerical simulation results available in literatures, and a good agreement was obtained. The simulation results showed that the two-layer model was suit for modeling the turbulent flow over a square rib and was more accurate than wall function method. Numerical simulation results indicated that upstream of the rib, the length of vortex I almost had no change with varying rib lengths under the same rib height and flow conditions (Re=1.4 × 10⁴, H=1.0), downstream of the rib, if L/H ≥ 4 the length of vortex II keeps almost unchanged for the varying lengths.