Theoretical And Experimental Research On Properties Of Texturde Mechanical Seal Based On Thermal-Fluid-Solid Coupling

The mechanical seal of stern shaft is an important componentof marine shafting,whose sealing performances directly affect both safety and vitality of ship navigation.Now,the key problem of the mechanical seal of stern shaft is both sealing and tribological properties,so surface texture shall be used to improve the sealing properties the mechanical seal and extend its working life.Based on the surface texture of the mechanical seal of tern shaft,Thermal-Fluid-Solid(TFS)coupling analysis,tribological performance test of material and sealing performance bench test were conducted,the effects of sealing ring material,texture parameters,operating conditions and other factors on the mechanical seal performances were researched,and texturing form was optimized.The research work and results are as follows:(1)The TFS model of the mechanical seal was established with ANSYS,the comparison between both results of modelsimulation and analysiswas carried out,and the rationality of the finite element model was validated.The research results show that the errors of both water film support force and surface support force are less than 6%,the contact pressure error is 14.3%,and the model is meet the application requirements(2)The tribological properties of polymer material specimens were tested.Based on specimens' friction coefficient and wear,the surface arranged with texture,texture parameters and material were selected.The results show that under most working conditions,both frictionand wear properties are better when the surface texture whose diameter is 1.2 mmis arranged on the surface of yellow Yanli specimen.(3)The bench test of the mechanical seal was carried out,the tribological and sealing performance parameters such as water film pressure,surface temperature,leakage and friction coefficient and so on were compared,the influence law of operating conditions on both texture and non-texture seals was analyzed,the effect of surface texture on the mechanical seal performance was evaluated.The results show that the surface texture can effectively reduce the friction coefficient and lowerthe temperature of the mechanical seal.(4)The tribological performances of different types of surface texture were compared with thermal-flow-solid coupling model,the influence of the various factors on the water film pressure,water film temperature and surface deformation was analyzed,the action effect of different texture on the reduction of water film temperature was discussed,the radial distribution state of the water film pressure both without and with texture seals along seal faceswas investigated(the formeris a linear relation,the latter increases as wave mode),the supercharging effect of three kinds of texture in partial area and the relative deformation rule of different sealing surface along the radial direction were studied.Results indicate that diamondtexturehas some characteristics:the cooling effect is obvious,supercharging effect slightly lower than other types of textures,deformation relatively small,and comprehensive performance the best.