Study On Aircraft Electro-expulsive De-icing System

Icing is one of the major sources of flight accidents, which therefore needs to be removed from the aircrafts. Among various de-icing systems, electrico-expulsive approach removes ice by the electro-magnetic repulsion force, which is featured by its low power consumption, high efficiency, little influence to flight stability, as well as flexible installation. With ANSYS simulator and based on magnetic-vector finite element method (FEM), this thesis builds the FEM models for the component. The electro-magnetic and mechanic properties of the electro-expulsive deicing system (EEDS) together with its deicing features are analysed by EM-structure transient coupling approach. The main content of this research is as following:A model was chosen according to the modified EEDS structure. The simulation results shows good accuracy by comparing with experimental and empirical results.The electro-magnetic properties of a single device unit was studied by varying the device dimensions and structure. The dependence of the strength of electro-magnetic repulsion applied to the moving layer upon device dimensions and structure was obtained as the result.Optimization was implemented by considering the number of layers and the electro-magnetic properties were analysed. It shows that the four layer structure possesses the most optimized features and simultaneously enhanced the stability of the device. When the device have a dimension of long 100 mm, width 1~5 mm, thickness 0.5 mm, plate distance 0.2 mm and a current pulse of 3000 A, the electro-magnetic force applied to the moving layer of a four layer device is 2.27~2.76 times as strong as that of a two layer device.The deicing features were studied in the situation of glaze ice, obtaining the variance of the deicing proportion and deicing form according to the different dimensions and structures of the device, the stimulating current and the icing conditions. Feature parameters for deicing devices were suggested based on this study: l=100mm, w=2-2.5mm, M=2.5-5mm, h'=0.2mm, five units, pulse amplitude I≥4500A, pulse width 0.7~1.0 ms, rising edge about 0.15 ms, deicing limit 4 mm, and deicing cycle time should be less than 2 minutes when flying in "moderate icing" condition.According to such results, 5-units, 4-layer devices were produced, whose repulsion strength was further measured by 0-3000 A pulse current. When the pulse amplitude is 3000 A and the devices length is 170mm, the repulsion strength is 0.9 Mpa.