BI-STABLE STATES IN THE WAKE OF A 35 ◦ AHMED BODY AT YAW

Övrigt konferensbidrag, 2017

Recent experimental observations by in the wake of a 35 ◦ back slant Ahmed body reveal the exis- tence of two stable states when the body is yawed [1]. The two flow states, flow state I and flow state II, are confirmed numerically by using the partially-averaged Navier–Stokes (PANS) formu- lation on unstructured meshes. Flow state I corre- sponds to a low drag/low lift state with the flow being fully separated, while flow state II corre- sponds to a high drag/high lift state, with the flow separating and reattaching over the back slant. For the Ahmed body at zero yaw angle (β = 0 ◦ ), flow state I is observed. This flow state is observed as the yaw angle is increased up to |β| ≃ 12.5 ◦ . As the yaw angle is increased beyond |β| = 12.5 ◦ , flow state II is observed. These findings are in good comparison with the experimental observa- tions of [1].