Unsteady RANS Simulation of Flow Around a 5:1 Rectangular Cylinder at High Reynolds Numbers

The unsteady flows around a stationary two dimensional rectangular cylinder with chord-to-thickness ratio B/D = 5.0 at high Reynolds numbers, Re_B = 5×10⁵, 1×10⁶, 1.5×10⁶ and 2×10⁶ (based on the free stream velocity and the chord length), are investigated numerically by solving the Unsteady Reynolds-Averaged Navier Stokes (URANS) equations with a standard high Reynolds number k-ε turbulence model. The objective of the present study is to evaluate whether the model is applicable for engineering design within this flow regime. Hydrodynamic results (such as time-averaged drag coefficient, root-mean-square of fluctuating lift coefficient, Strouhal number and mean pressure distribution around the rectangular cylinder) are compared with published experimental data. The mechanism of vortex shedding is also discussed.