Wall-Modeled Large Eddy Simulation of Flow over an Inclined 6:1 Prolate Spheroid

Wall-modeled large eddy simulation (WMLES) and Reynolds Averaged Navier-Stokes (RANS) calculations were performed to predict the forces and moments acting on a 6:1 prolate spheroid inclined 20 deg with respect to the inflow at a Reynolds number of 4.2 million. Overall, the RANS resulted in flow separation behavior similar to what has been observed in experiments. In the WMLES, however, the primary separation lines occurred earlier along the azimuth of the prolate spheroid, resulting in the separation extending further forward along the longitudinal axis of the prolate spheroid, nearly reaching the tip of the bow. This discrepancy in separation behavior likely originated from the tripped boundary layer in the experiments and the natural transition modeled in the WMLES. A grid study also was conducted to assess the sensitivity of the wall model to variations in the height of the first cell in the boundary layer. Two wall spacings were investigated. The impact of the flow separation variations that result from the simulation type and wall spacing on the integrated forces and moments acting on the prolate spheroid will be discussed in the meeting.