Research On Behavior Of Mechanical Seal During Transient Operation Used On The Ships

Nowday, for the complicated working conditions and influenced by several kinds of conditions, also the research to mechanical seal related to several acdemic fields, such as Fluid Lubrication, Tribology, Contact Theory, Heat Transfer Theory ect., the literates don't absolutely acquire with the working principle of the mechanical seal. It mainly focuses on the deformation of seal faces and contact and frictional state. While, the film thickness between the seal faces is extremely thin and the deformation of seal faces is extremely small, which both are micro-size, computing the characteristic of the seal through the traditional methods can not meet the accuracy requirement. Also, when research through some softwares, a Multi-physics coupling is necessary, but this is too difficult to do this. The article use the basic theoris, combining the software of ANSYS and MATLAB, analysed the transient characteristic of mechanical seal and the characteristic of vibration process of seal ring in the small perturbation condition.1) In the analysis of transient properties for the mechanical seal during the start-up, firstly, the Mechanical Influence Coefficients, Thermal Influence Coefficients and Temperature Influence Coefficient were computed, then the thermal deformation analysis for the seal rings was carried out by programing through MATLAB combining the influence coefficient method, then the mechanical deformation was did. The result of the mechanical deformation was acted as loads and loaded on the seal faces for the next thermal deformation analysis. So the purpose of coupling between the thermal deformation and mechanical deformation is achieved. In the coupling analysis between the thermal deformation and mechanical deformation, the film between the seal faces and the roughness of the faces was considered, the contact frictional heat between the faces and the shearing heat among the faces and sealed medium. The change distributions of the contact pressure, film pressure and the flow rate during the start-up are obtained.2) In the dynamic analysis of the mechanical seal ring, the article disintergrate the vibration into the axial vibration and angular oscillation, then analysed them separately. During the analysis, the action of the contact and film between the faces were considered, the action of the film was broken down into hydrostatic pressure, hydrodynamic pressure and squeeze pressure. The action of squeeze during the axial vibration and the hydrodynamic during the angular oscillation was considered. Finally, the contact pressure and film pressure distribution at any time and the flow rate during the vibration were obtained.