Theoretical And Experimental Research Of The Electro-impulse De-icing System For Aircraft

The micro-power electro-impulse de-icing technology as a mechanical de-icing system has a good application prospect.It has the advantages of low energy consumption,easy maintenance and high reliability comparing with other de-icing methods.Although the micro-power electro-impulse de-icing system has been successfully applied to the Russian Il series aircraft,due to military secrecy,other countries have not yet successfully developed this de-icing technology.To this,the method combining theoretical and experimental research is adopted in this paper to optimize the circuit parameters of the micro-power electro-impulse de-icing system.The theoretical research of micro-power electro-impulse de-icing system mainly includes three aspects: electro-dynamic research,structural-dynamic research and de-icing prediction research.The main research contents of this paper are as follows:Considering the mutual inductance between the skin and the impulse coil,the influence of mutual inductance on the peak impulse current and the time required to reach the peak current were analyzed.A three-dimensional electromagnetic eddy current field analysis model of the impulse coil-skin was established.The magnetic field strength around the skin is calculated by the surface smooth finite element boundary element(FEFEM-BEM)coupling method,which has the characteristics of high calculation accuracy and less computer memory.Under the same grid density,the calculated results obtained by the FS-FEM-BEM coupling method are closer to the measured results than that of the FEM-BEM coupling method,which shows that the method is correct and reasonable.On this basis,the relationship of the impulse force at different positions of the skin varies with time was obtained.Finally,the effects of thickness of the skin,conductivity of the skin,the gap between the impulse coil and skin,and the circuit resistance on the peak impulse force are analyzed,which provides a reference for the subsequent design of the micro-power electro-impulse de-icing system.A three-dimensional structure dynamics analysis model of the skin-ice layer was established.Modal analysis of the skin is performed by the surface smoothed finite element method(FS-FEM),the calculated results are compared with those obtained by the simulation software,it is indicated that the calculation method is correct.Since the stress between the skin and the ice layer is the main factor affecting the ice layer shedding,the maximum shear stress and normal stress between the skin and the ice layer were solved by the above calculation method.Finally,the factors affecting the maximum normal stress and the maximum shear stress between the skin and the ice layer are analyzed,such as the magnitude of the electromagnetic impulse force,the distribution of the electromagnetic impulse force,the material characteristics(density and elastic modulus),the thickness of the skin,and the density of ice layer.The tensile test was carried out in the Xuefeng mountain natural icing test station,the tensile stress and shear stress between the ice layer and the skin were obtained.The tensile stress and shear stress were used as the interlayer bond strength of the de-icing criterion,and a test platform was set up to carry out the de-icing test in the natural icing test station.Compare the de-icing results obtained from the test with the de-icing prediction results obtained by using various de-icing criteria,and select the appropriate de-icing criterion.Parameter analysis and equipment development based on micro-power electroimpulse de-icing system were carried out.Firstly,the efficiency of converting magnetic energy into mechanical energy is the optimization goal,the inner diameter,outer diameter and turns of the impulse coil are optimized by the method of electrodynamic calculation.When the electrical frequency is equal to the natural frequency of the skin,that is,when the skin resonates,the de-icing effect is best,and the capacitance value can be calculated.Then,the mechanical energy required to de-icing on the skin side is obtained by the structural-dynamic calculation,and the energy required to de-icing of the impulse coil is calculated according to the conversion efficiency,and the voltage across the capacitor can be obtained.According to the above circuit parameters,an electro-impulse de-icing device was set up and the de-icing experiment was performed.The deicing results obtained from the experiment were compared with the expected de-icing results during the design process,it is verified that the design process of the micro-power electroimpulse de-icing device is correct and reasonable.The flat de-icing experiment was carried out in the multi-functional artificial climate chamber of Chongqing University.The influence of the icing environment on the de-icing effect under the action of the same impulse device and the change of the deicing rate with the thickness of the ice layer under the same icing environment were analyzed.Aiming at the problem that the actual wing and the aluminum plate have the same material but different curvatures,and due to the limitation of experimental conditions,this article takes a section of ribs as the research object.The effects of the number,position and start-up time of the impulse coil on the de-icing effect were analyzed by numerical simulation.It provides an important reference for the subsequent installation and application of the micro-power electro-impulse de-icing device.