AERODYNAMICS OF A FINITE WING WITH SIMULATED ICE

The flowfield about a semispan finite wing with a simulated leading-ed ge ice accretion is studied experimentally. The finite wing was tested in both a straight and swept wing configuration. Surface pressures, f luorescent oil flow visualization, and helium bubble flow visualizatio n studies of the flowfield are reported. The presence of the simulated ice accretion produces a large leading-edge separation bubble which r esults in a global change of the pressure field, reduction of lift and increase in drag. Fluorescent oil now visualization and pressure dist ributions from the centerline of the straight wing at low angles of at tack show a predominantly two-dimensional flowfield on the wing's uppe r 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 drastica lly changes the flowfield near the root. The measured span loads on th e straight wing compare well with the computational results when the e ndwall is properly modeled. The swept wing has a highly three-dimensio nal flowfield. Pressure distributions indicate higher lift near the ro ot and lower lift near the tip. Helium bubble traces show a strong spa nwise now component an the swept wing. These results are in good quali tative agreement with Navier-Stokes calculations.