Aerodynamics of a finite wing with simulated ice

The flowfield about a semispan finite wing with a simulated leading-edge ice accretion is studied experimentally. The finite wing was tested in both a straight and swept wing configuration. Surface pressures, fluorescent oil flow visualization, and helium bubble flow visualization studies of the flowfield are reported. The presence of the simulated ice accretion produces a large leading-edge separation bubble which results in a global change of the pressure field, reduction of lift and increase in drag. Fluorescent oil flow visualization and pressure distributions from the centerline of the straight wing at low angles of attack show a predominantly twodimensional flowfield on the wing's upper surface. Three-dimensional effects due to the tip-induced vortex and root-wall interaction become important at high angles of attack. Oil flow visualization shows that wall suction near the wing root drastically changes the flowfield near the root. The measured span loads on the straight wing compare well with the computational results when the end wall is properly modeled. The swept wing has a highly three-dimensional flowfield. Pressure distributions indicate higher lift near the root and lower lift near the tip. Helium bubble traces show a strong spanwise flow component on the swept wing. These results are in good qualitative agreement with Navier-Stokes calculations.