Effects of scallop ice characteristics on the flow field structures and the aerodynamic performance of an airfoil

In the present study, an experimental investigation was carried out on the effects of scallop ice characteristics on the flow field structures and aerodynamic performance of an airfoil. Detailed measurements were performed in a low-speed reflux wind tunnel by utilizing particle image velocimetry technique and a high-sensitivity six-component balance. A parameter study on the gap width and the cutting plane angle of the scallop ice was conducted. The results showed that the gap width and the cutting plane angle had significant effects on the aerodynamic performances of airfoils with scallop ice. The change of the gap width and the cutting plane angle also had apparent influences on the flow field parameters when the angle of attack exceeded 6°. The lift and pitching moment coefficients of airfoils decreased as the gap width increased or the cutting plane angle decreased. In the selected region above the airfoils, the average dimensionless vorticity, normalized turbulent kinetic energy, and normalized Reynolds stress gradually decreased as the gap width increased. In addition, the gap width and the cutting plane angle did not have predictable influences on the drag coefficients of the airfoils and the average dimensionless velocity in the selected region.