Computation of the Flow Over a Sphere at Re = 3700: A Comparison of Uniform and Turbulent Inflow Conditions

Abstract

A highly resolved computation of the flow past a sphere at Reynolds number Re = 3700 using a finite element method (FEM)based residualbased variational multiscale (RBVMS) formulation is performed. Both uniform and turbulent inflow conditions are considered with the uniform flow case validated against a previous direct numerical simulation (DNS) study. We find that, as a result of adding freestream turbulence of moderate intensity, the drag force on the sphere is increased, the length of the recirculation bubble is reduced dramatically, and the nearwake turbulence is significantly more energetic than in case of uniform inflow. In the case of uniform inflow, we find that the solution exhibits low temporal frequency modes, which necessitate longtime simulations to obtain highfidelity statistical averages. Subjecting the sphere to turbulent inflow removes the lowfrequency modes from the solution and enables shortertime simulations to achieve converged flow statistics.