Experimental Study Of Ice Accretion On Rotating Spinner And Numerical Simulation Of Shed Ice’s Trajectory

When the aircraft flys through the clouds with supercooled water droplets, ice accretion occurson the upwind surface of the rotating spinner in the engine inlet. Accreting ice leads to the mass flowrate of airflow reduced and the aerodynamic performance deterioration, which results in the thrust lost.And once the shed ice from the spinner enters the engine, it may damages the rotating blades withhigh speed, which endangers the aircraft. The research of the icing on the aircraft wings and thetrajectory simulation of shed ice from the wings has been widely conducted in the abroad, but there islittle public literature about the corresponding research for the rotating spinner. The research in thisfield is almost absence in our coutry. The current reseach aims at the simulating experiments of iceaccretion on rotating spinner and numerical simulation of the trajectory of shed ice form the spinner inthe flow field of engine inlet.Firstly, simulated icing tests on six sub-scaled rotating spinner models with different cone anglesare conducted in a icing wind tunnel. The icing similar parameters group for the rotating surface isderived based on the icing similarity theory for the static surfaces. Then the calculation method of theexperimental icing parameters is developed. And then the rotating icing equipment for spinner isdesigned. The ice accretion process and ice shape on the rotating spinner are recorded by a high speedvideo system in the test. The test results show that in the icing process the ice on rotating surfacedevelops from even glaze ice to rough glaze ice, grain shaped ice and finally feather shaped ice. Thecone angle of the rotating spinner has significant effect on the shape and thickness of the ice. Whenthe cone angle is less than or equal to74°, the ice appears needle or grain, which may not shed fromthe spinner. When the cone angle is greater than80°, the ice is feather shaped, and would partly shedfrom the icing surface. The mechanism of ice accretion on the rotating spinner result form theunsteady flow of water film and centrifugal force is also revealed in the thesis.And then, the motion model of a spherical shed ice in the flowfield of engine inlet is establishedunder the rotating coordinates system, which takes the aerodynamic drag force, the pressure dragforce, the centrifugal force and Coriolis force into account. Subsequently a trajectory computationcode is developed based on the model. Using the code and the flowfield data of a turbofan engine inletcomputed by NUMECA, the trajectory of spherical shed ice is simulated. The results show that themotion time of the spherical ice from the surface of the rotating spinner to the inlet surface of theengine is less than20ms. The shed ice with larger diameters would tend to enter into bypass. The shed ice with more dowmstream shedding position on the spinner would tend to enter into core.