The expanding process of turbulent separation bubble induced by a horn ice on the leading edge of an airfoil for business jet was investigated numerically with IDDES. Through comparing with the experiment results of critical stall condition, the fidelity of method for detailed simulation of ice-induced separation was verified firstly. Then the separation bubble under post-stall conditions was investigated in the aspects of both the features of averaged static flowfield and the behaviors of transient shear-layer vortices. The averaged results manifested that during the stall process, the bubble expanded with stretching and deformation for reattachment line and turbulence region were shifted towards trailing edge and spread continually. The corresponding extending and descending of pressure plateau with weak pressure gradient resulted in an early but mitigated stall pattern consequently. From the transient flowfield, it was observed that the entire evolution process of bubble was driven by the hairpin-type vortices generated from the shedding shear-layer with K-H instability. The propagation direction of these shear-layer vortices was affected by the entrainment of external flow. Under the post-stall condition, the motion of vortices towards the wall was delayed with the increasing of incidence and the interaction between vortices and wall was weakened correspondingly, which leaded the gradual decrease of reattachment effect and the continuous expanding of recirculation region.

用IDDES数值研究了公务机翼型前缘上的角冰引起的湍流分离气泡的膨胀过程。通过与临界失速条件的实验结果进行比较，首先验证了详细模拟冰诱发分离的方法的保真度。在失速条件下，从平均静态流场特征和瞬时剪切层涡旋特性两个方面研究了分离气泡。平均结果表明，在失速过程中，气泡随着拉伸和变形而膨胀，重新附着线和湍流区域向后缘移动并不断扩散。相应的压力平台在压力梯度较小的情况下的扩展和下降导致了较早但缓解的失速模式。从瞬态流场中，观察到气泡的整个演化过程是由具有KH不稳定性的脱落剪切层产生的发夹型涡旋驱动的。这些剪切层涡旋的传播方向受到外流夹带的影响。在失速后状态下，涡流向壁的运动随着入射的增加而被延迟，并且涡流与壁之间的相互作用相应地减弱，这导致了重新附着效应的逐渐减小和再循环区域的不断扩大。观察到气泡的整个演化过程是由具有KH不稳定性的脱落剪切层产生的发夹型涡旋驱动的。这些剪切层涡旋的传播方向受到外流夹带的影响。在失速后状态下，涡流向壁的运动随着入射的增加而被延迟，并且涡流与壁之间的相互作用相应地减弱，这导致了重新附着效应的逐渐减小和再循环区域的不断扩大。观察到气泡的整个演化过程是由具有KH不稳定性的脱落剪切层产生的发夹型涡旋驱动的。这些剪切层涡旋的传播方向受到外流夹带的影响。在失速后状态下，涡流向壁的运动随着入射的增加而被延迟，并且涡流与壁之间的相互作用相应地减弱，这导致了重新附着效应的逐渐减小和再循环区域的不断扩大。