Computational Analysis Of Water Droplet Impingerment Property For The Inlet Struct And The Cone

Ice accretions may occur on the air inlet, entry components and power devices of an aero-engine when the airplane flies on icing conditions.Ice accretions on the inlet and entry components refers to that on the leading edge, the cone and structs ahead of the compressor, etc. Ice accretions on engine will lead to engine performance deterioration, mass addition and vibration .In order to predict the position of ice and types of the ice, we need to know the trajectories of water droplets and the impinging points which requires the study of droplet movements to ascertain water droplet impingerment property for the subject .This article takes the inlet system for research objects, using commercial software fluent to numerically simulate the flow field of the entry components and the cone. Based on the discrete results,a new method to calculate the local collection coefficient by using fluent user defined functions (udf) is developed . The engine inlet parts are usually made into wing shapes, so the leading edge of the engine can be roughly handled by wing pattern. Based on the above treatment of the inlet struct,this article describes specific methods calculating the air flow and the specific steps establishing water movement equations .With the fluent software discrete model and the user defined function, a method applicable to calculate the local collection coefficient of the two-dimensional and the three-dimensional wing shapes is developed.Results show that the local collection coefficient of the two-dimensional wing shape coincides with the results mentioned before.By comparing the local collection coefficient of the two-dimensional wing shape and that of the three-dimensional wing shape, we suppose this calculation method is feasible.And then, based on the software fluent, this article studies the calculating method of water droplet impingerment for the cone and uses the method for different cone angles and rotational speeds. The computational results indicate that as the cone angle grows, the local collection coefficients fall rapidly and the impingement limits become small along the cone surface, and as the rotational speed increases, the local collection coefficients fall rapidly and the impingement limits become small along the cone surface.Finally, this paper introduces test studies for the anti-icing system emphasizing the icing wind tunnel and the similar criterias it should follow and then verifies those similar criterias by numerical method. The results show that the collection efficiency of the full size wing matches the resulets of the iconic model by the method mentioned above.