PIV investigation on airfoil with ice accretions and resultingperformance degradation

摘要

An experimental study was conducted to investigate the effect ofice accretions on the aerodynamic characteristics of a 100 mm-chord NACA0012 airfoil section. Four different configurations of the airfoil modelwere considered: clean profile and profile with glaze, rime and mixedice-accretion. shapes. The considered shapes were derived frommeasurements performed at the NASA Lewis Icing Research Tunnel (IRT).Tests were performed in the closed test section of an open circuitcalibration tunnel: the chord Reynolds number was about 200000. Velocityfield was measured by means of PIV technique on the clean and mixedairfoils, whereas aerodynamic coefficients for all the different iceaccretion shapes were measured as a function of airfoil incidence, bymeans of a three component balance. The experimental results showremarkable aerodynamic characteristics decay due to the simulated iceformation: glaze configuration shows worst performances with inversionof the lift-incidence curve and a dramatic increase of the dragcoefficient. PIV measurements show large regions of separated flow evenat low incidence and for moderate amount of ice (mixed shape): in fact,due to the low chord Reynolds number, no flow reattachment occursdownstream the separation