The influence of laminar-to-turbulence transition of the laminar separation bubble (LSB) on the dynamic stall process of a pitching foil was investigated using transition SST k-ω turbulence model. As the LSB moves to the leading edge, the strong strain rate produces a pronounced laminar-to-turbulence transition, resulting in a turbulent mixing, faster turbulent reattachment, and shrinkage of LSB. This transition leads to the enhancement of the friction coefficient after the reattachment point and delays the suction collapse and evolution of secondary vortex. A baseline SST k-ω model was also applied. Without the transition mechanism, the suction collapse occurs too early, and the downstroke relaminarization is absent. The oscillation of the downstroke lift curve is severer using the SST model than that using the transition SST model. This study extends the detailed validations of transition model and helps improve the understanding of the influence of the transition on the dynamic stall process.

使用过渡 SST k-ω 湍流模型研究了层流分离气泡 (LSB) 的层流到湍流过渡对俯仰翼动态失速过程的影响。当 LSB 移动到前缘时，强应变率会产生明显的层流到湍流的转变，导致湍流混合、更快的湍流再附着和 LSB 的收缩。这种转变导致重附着点后摩擦系数的增加，并延迟了二次涡的吸力崩溃和演化。还应用了基线 SST k-ω 模型。没有过渡机制，吸入塌陷发生得太早，下冲程再分层不存在。使用 SST 模型的下冲程升力曲线的振荡比使用过渡 SST 模型的更严重。