A study of the icing problems on propeller-type rotary wings

This dissertation is concerned primarily with thedevelopmentof a code for computing the aerodynamicperformance of aircraft propellers for clean. rime- andglaze-iced configurations for a given icing time. First,the inviscid. incompressible flow field at specified radiallocations is computed by a conformal mapping technique.Next. the DROPlet trajectories and impingement points aredetermined. hence the collection efficiency at each radiallocation. The ice fraction, f. is then computed to determinethe type of ice that forms Crime or glaze). Finally,empirical cor r el at.i ons ale applied in conjunction wi t.h a”strip analysis” procedure to compute and eval uat.e theresulting deqr adat.Lon in propeller per f or mance ,Threedifferent encounters were subjected to computations by thepr-esent code and comparisons were made against availablepredictions and expar-Lment.a l data found in the li terature.These comparisons yield reasonable agreements and confidencein the code was therefore asceltained.Distlibutions of centrifugal and adhesive fOlces alongblade span at various advance ratios were computed toeval uat.e t hei r lel at.i ve inter ac t i oris wi t.h ice accreti on.This type of comput.at.i on. was esti maled i mpor t.ant, to theinvestigation of ice-accretion-induced blade stresses.Previous investigations on ice accretion. experimental