Unidirectional Fluid-Solid Coupling Numerical Study On Film Seal Used On High Temperature Oil Pumps

Single Bellow Mechanical Seal is widely used in high temperature oil pumps in the petroleum and petrochemical industry, but there are so many problems under the condition. Now a new Dual Bellow Mechanical Seal is produced to replace it. It is a question whether the seal can satisfy the requirement by the condition. There are many works to do.A period model of moving ring-stationary- ring film for Fluent is constructed by Gambit. three-dimensional flow field and temperature field are numerical simulated by means of computational fluid dynamics software FLUENT with the energy equation momentum equation and coupling equation. The best film thickness is 2.5 μm is solved by Fluent. And analysis the influence on performance parameters of seal(opening force, pumping output, stiffness of film) by operation parameters such like speed, temperature difference and pressure difference. It can be concluded that in the low speed the relation of viscosity-temperature has few influence on performance parameters of the seal in high temperature oil pump except for temperature difference. There are few means to consider the changing of viscosity by temperature changing except for the changing of temperature under the condition.A period model of moving ring-stationary ring for Mechanical APDL is constructed by Mesh software which belongs to ANSYS Workbench. Stress coupling, thermal coupling and stress-thermal coupling is computed by Fluent and Mechanical APL based on ANSYS Workbench. The influence on face deformation by stress coupling thermal coupling and stress-thermal coupling is researched. In every condition, the affection of speed, temperature difference, pressure difference is computed. It can be concluded:(1) Circumferential wave deformation and radial taper deformation on the seal face are created by stress which is benefit for the stability of the film working, and the numerical value of the two type of deformations is very small.(2) The maximum deformation is the radial taper deformation created by heat, and is far larger than deformation by stress even in the same magnitude order with the film thickness. So the influence of heat should be concerned in the further computation.(3) The stress in moving ring and stationary ring is mostly created by heat. The value of stress is far less than the yield strength of SiC. In some place, secondary stress appears which less than the yield strength of SiC. Methods like optimizing the geometry construct of the seal rings.(4) The material which is more stiff with less inflation by the heat should be concerned when the material of seal rings are choosen.