Numerical study of the effects of discontinuous ice on three-dimensional wings

Abstract

Ice accretion has adverse effects on aircraft, so it is very important to study the flow field of iced wings. Unlike previous studies that typically focused on continuous ice, this paper conducts a numerical study of the flow field around discontinuous ice. A modified laminar-turbulent transition model that incorporates large separation correction is employed for the study of discontinuous ice. An iced swept wing was chosen to validate the modified model's capability in predicting aerodynamic performance. The impact of discontinuous ice on both straight and swept wings was studied. For the straight wing, the effect of discontinuous ice with different gap widths on aerodynamic characteristics was investigated. The results show that the reduction in lift caused by discontinuous ice is typically lower than that caused by continuous ice. However, at angles of attack less than 7°, small-gap discontinuous ice causes more substantial reductions in lift compared to continuous ice. This is because small-gap ice causes greater separation at the leading edge, significantly reducing the suction peak of pressure. For the swept wing, the effect of sweep on discontinuous ice was studied. It was found that the swept effect causes asymmetric separation behind the ice shape. At higher angles of attack (greater than 4°), the impact of different ice configurations on lift shows an opposite trend on swept wings compared to straight wings.