Study On Transient Characteristics Of Hydrodynamic Mechanical Seal Based On Multi-field Interaction

The lubrication characteristics of fluid film are the key to the performance of hydrodynamic mechanical seal.However,it is difficult to simulate the flow field in seal gap because of the extremely thin fluid film.At present,the researches on hydrodynamic mechanical seal is mainly based on steady simulation so that the influence of seal face deformation and transient characteristics is always ignored.Supported by the National Natural Science Foundation of China(51279067),the hydrodynamic mechanical seal with the spiral groove texture was chosen to be the research object,and the multi-field coupling model and unsteady analysis method were improved in this paper.The deformation law of sealing ring under multi-field coupling and the transient characteristics of the fluid film after the end face deformation were the research emphasis.And an orthogonal test was carried out to analyze the effects of the spiral groove parameters on the sealing performance which could provide a reference for the design and research of mechanical seal.The main work and conclusions of this paper are as follows:1.A multi-field coupling model and unsteady analysis method for hydrodynamic mechanical seal the spiral groove texture under conventional working conditions were presented,and the transient characteristics under different multi-field coupling were obtained.The simulation method and results also have some reference value for unsteady study of other micro-scale flow.2.Based on the two-way fluid-structure interaction model of rotating ring-fluid film-stationary ring,the unsteady simulation of fluid film was carried out with consideration of the sealing ring deformation,and the structural characteristics of sealing ring and flow characteristics of fluid film after deformation were discussed.The results indicated the deformation behaviors and the change of stress and strain in sealing ring with time,and the transient characteristics of the fluid film and sealing performance after deformation were analyzed too.It is found that the fluid film pressure fluctuation characteristics and sealing performance are obviously affected by deformation.3.On the basis of the fluid-solid interaction,unsteady simulation of the temperature field of the flow field was conducted,and a two-way fluid-structure-heat interaction model for hydrodynamic mechanical seal under conventional operating conditions was proposed.The deformation and stress distributions in sealing ring under fluid-structure-heat interaction were obtained based on the model.Then according to the comparison of transient characteristics of the fluid film and sealing performance between different mutil-field,the influence law of pressure field and temperature field on mechanical seal characteristics were analyzed.4.Based on the fluid-structure-heat interaction model,a orthogonal test of groove diameter ratio,groove width ratio,spiral angle and groove depth was carried out to study the influence of spiral groove parameters on the maximum deformation of sealing ring and the transient characteristics of liquid film with taking the maximum deformation,pressure fluctuation coefficient and sealing performance parameters as analysis objects.The influence lever of spiral groove parameters on different characteristics was obtained,and the range of parameters with lower pressure fluctuation and better sealing performance was summarized.5.The sealing performance test of the hydrodynamic mechanical seal with different spiral groove parameters was carried out,and the rationality of the mutil-field simulation method and the results of the orthogonal test were verified by comparison between the test values and simulation results.