Numerical simulation and analysis of bubble evolution in ice wing separation during stall process

Application of Improved Delay Separation Eddy Simulation (IDDES) based on SST turbulence model in numerical simulation study of the development process of complex stall separation flow caused by typical double horn ice at the Leading Edge of GLC305 Wing. The numerical simulation results of the stall process indicate that the unsteady shedding of the shear layer behind the horn ice and the transport process of vortex determine the basic characteristics of separating bubbles. Due to the fact that the detachment angle of the shear layer increases with the increase of the angle of attack, the transport direction of vortex shifts towards the background flow. As a result, the geometrical scale of separation bubble is gradually increased and the reattachment region shifts backward continually. The disintegration of separation bubble flow structure occurs when the vortex completely enters the wake region. The related process of gradual changing lift leads a relatively mild stall performance of the iced airfoil.