| With the vigorous development of our country’s Marine business,there puts forward higher request for the quickness and battery life of kinds of ships and underwater vehicle, and as a result, the energy consumption and carbon emissions also have attracted widespread attention.Reducing the friction resistance and realizing energy conservation and emissions reduction become an important research subject.Researchers home and abroad do a lot of works in surface drag reduction mechanism analysis and experimental demonstration, but most of methods are restricted from the popularization and application in the engineering practice due to their high lost of equipment requirement and complexity the technological process.In this paper, on the basis of the reference current drag reduction technology research, we proposes a self-assembly technology based on polymer coating to prepare a kind of surface with low surface energy and bionic micro-nano structure.Using solvent evaporation coating self-assembly process caused by capillary force, interfacial tension, temperature gradient and other mechanics effect make the micro/nano particles in the equilibrium state spontaneous assembly, thermodynamic stability of the three-dimensional orderly piles composite structure of micro-nanometer combination. By simulating function of self-cleaning lotus leaf surface, we obtain the organic unity between the chemical characteristics on the coating surface and macro and micro physical structure of,and combine low adhesion characteristics of low surface energy material and the structure of the micro-nano composite interface of cavitation effect to realize the purpose of effectively reduce the skin friction drag, for a technical route of engineering application(1) Combine with the features and performance, determine the film-forming material, pigment, the variety and dosage of cosolvent, etc; Obtain the coating component ratio on the basis of optimized experiments By using the methods of mechanical chemistry and ultrasonic dispersion of agglomeration of nanoparticles modified dispersion and preparation of composite particle size between5μm-15u m micro-nano composite particles.(2) By using of building air spraying device platform, prepare coating film on the surface of the substrate surface/with adjusting the self-assembly process parameters of drying curing film.(3) Using the coating adhesion test instrument, the contact Angle measurement instrument and field emission scanning electron microscopy (SEM) and other instruments and equipments performance, test quantitative characterization of the coating surface and the micro-nano particle size ratio, temperature and other process parameters and surface characteristics of focuses on related forms and correlation analysis, the results show that the experiment of the preparation of the coating has the class micro-nano structure of lotus leaf surface for33.35mN/m;When the micro-nano size than for1000, maximum surface coating surface contact Angle is160°, when self-assembly in23℃environment temperature coating the optimal degree of self-assembly, the coating has the best performance.(4) Do flow resistance test system on the drag reduction properties of the coating made by experimental study, by comparing the different flow field under the pressure of various kinds of materials on the surface of the drag reduction effect, found that the experimental preparation of low surface energy of bionic micro-nano coating drag reduction effect is best, the highest drag reduction rate can reach24.86%.Using CFD simulation software FLUENT to do numerical analysis on coating near wall flow field, explores the drag reduction mechanism of bionic micro-nano coating, and think that interface effect of micro bubbles formed by the cavitation of the micro-nano composite structure, and low adhesion characteristics of low surface energy materials are the reason for drag reduction of the caused low surface energy bionic micro-nano composite coating surface. |
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