Simulation And Experimental Study On Cavitation Effect Of Friction Pair Surface Texture

The reasonable surface texture on the sliding friction pair can effectively improve the lubrication performance of the friction pair.However,there are still many imperfect aspects in the research of surface texture,especially the research on surface texture induced cavitation effect is relatively scarce,lacking sufficient theoretical support and intuitive experimental research.Therefore,the paper uses numerical simulation and experimental methods to study the effect of surface texture induced cavitation.In numerical simulation,the Fluent software is used to calculate and analyze the established fluid lubrication model considering surface texture,and the effects of cavitation on hydrodynamic lubrication are studied theoretically.While considering cavitation effect,the texture models for different sizes and different morphologies are solved,and the mechanism and influencing factors of surface texture induced cavitation effect are analyzed.Finally,the influence of the spacing for the two textures on the induced cavitation effect is initially explored.In the experimental aspect,clear cavitation effect images are collected by using the visual experimental bench in order to verify that surface texture can induce cavitation of lubricating oil.The calculated friction coefficient and the acquired cavitation effect image are used as evaluation criteria to analyze the influences of different texture morphologies and size parameters on cavitation effect and hydrodynamic lubrication.The rationality of the model is verified by comparing with the simulation results.The simulated values have the same trend as the experimental results.The results show that the surface texture will induce the cavitation effect of the lubricating oil under certain speed and load conditions,and bubbles will be generated at the outlet of the texture,and the cavitation effect will affect the lubrication performance of the friction pair.As the speed increases,the friction coefficient of the friction pair is gradually reduced,and the hydrodynamic lubrication effect is gradually enhanced;the morphology parameters of different textures have different influences on cavitation and hydrodynamic lubrication effect between frictional surfaces with micro-textures.The larger the length and width of the surface texture,the greater the cavitation effect,but the more difficult to induce cavitation;When the texture depth is close to the oil film thickness,it has the best effect in terms of inducing cavitation and improving lubrication;Considering the textures with same size,the square textures are better than round and triangle textures.In addition,it was found in the experiments when area density of texture is 8%and the texture are arranged at inlet area of the sample,the best hydrodynamic lubrication effect of the surface texture on the sliding friction pair can be obtained.And within the range of working conditions selected by the experiment,the greater the speed,the more pronounced the improvement effect.