Study On The Experiment Of Novel Anti-icing And De-icing System Based On Bi-stable Structures

The liquid water will freeze rapidly below o? on the surface of functional structure and equipment,which will cause not only a functional loss,but also a serious concern.The most efficient way to anti-icing and de-icing is electrothennal method in traditional systems.The main principle of the electric method is to convert electrical energy into heat,so that the temperature of the material surface is higher than the freezing point(0 ?)and achieve the anti-icing and de-icing function.But the heating method needs constant electrical energy both in anti-icing and de-icing processes.Moreover,the liquid water will adhere to the surface and refreeze below o?.A novel thermo-mechanical anti-icing/de-icing system based on bi-stable laminate composite structures with superhydrophobic surface is designed to solve these problems.The main structure of the new anti-icing and de-icing system is bi-stable structures.The system is divided into three layers:superhydrophobic material,bi-stable structure and heating film.The super-hydrophobic material has the effect of reducing the adhesion of water droplets,prolonging the freezing time of water droplets and reducing the adhesion force between the surface and ice layer.The bi-stable structures with two stable states have good thermal conductivity.In addition,the bi-stable structures could achieve stability state transition under a variety of driving factors and produce low-frequency mechanical vibration.As to heating film,which is made of polyimide(PI)and electrical heating alloy,can generate heat in a short time to drive the bi-stable structures and melt the surface of the system ice.The new anti-icing de-icing system has combined the characteristics of the three materials and used the electrothermal mechanical coupling mechanism to achieve the achieve desired results.The main research contents are as follows:(1)The bi-stable structures were prepared by using carbon fiber-epoxy resin.The copper is bond on the surface of bi-stable structures to fabricate superhydrophobic surface using chemical etching method.The water static contact angle of surface is aim to reach 150°and the rolling angle is less than 10° with corrosion resistance,self-cleaning characteristics,high-intensity UV tolerance,tolerance on high and low temperature alternating and long service life.(2)The experiments of superhydrophobic material which based on the theory of wettability on the surface of solid material are conducted including delayed icing test,icing test of the clean surface and the surface containing impurities.Moreover,the results of experiments indicate that the superhydrophobic surface can prolong the freezing time of water droplets significantly.The superhydrophobic material is compared with the ordinary material in anti-icing test to verify the effect of reducing the icing on material surface.(3)As the major structures of anti-icing and de-icing system,the bi-stable structures are analyzed by using finite element analysis so:ftware ABAQUS,including the thickness of single layer,stacking sequence of plies and the width of heating area.In the meanwhile,the anti-symmetric bi-stable structures are also studied as contrasts to prove that the heating method is more suitable for the asymmetric cross-ply bi-stable structures,which provides references for the experiments.Finally,the reliability of the finite element method is verified by comparing the experimental results with the numerical simulation results.(4)The new composite structures are assembled by copper-based superhydrophobic material,bi-stable structures and PI-electrothermal soft film.Moreover,the experimental platform of low temperature environment is set up and the tests of anti-icing and de-icing are conducted at subzero temperature.The final results of tests proves that the system has good performances on anti-icing and de-icing with the abilities of removing the liquid water formed by the melting of the ice and preventing the water droplets from refreezing.