Numerical Analysis Of The Dynamic Lubrication Performance Of Laser Textured Mechanical Seal Face

Surface texturing of mechanical seal plays a decisive part in the working performance and service life of the seal surface. Mechanical seal surface with laser textured becomes the focus of research recently. So researching different surface textures and the optimization of the parameters on the mechanical seal not only have significant meaning to the lubrication theory, but also have tremendous practical value to the application of mechanical seal.Based on plenty of references at home and abroad, the hydrodynamic lubrication performance of the mechanical seal surface with laser textured cone and spiral grooves shaped micro-asperities is studied specifically.On the one hand, the mechanical seal surface with laser textured micro-cones is studied specifically and the lubrication factors is analyzed, simplified and approximated, and physical model of mechanical seal surface with micro-cones is established. Then the numerical model and its boundary condition are gotten based on the physical model. With the setup of numerical model, tribological system of the micro-cones on the mechanical seal is converted into a complex non-linear problem of the Reynolds equation and film thickness equation. The controlling equation is discretized by finite difference method (FDM), and solved by Guass-Seidel iterative line relaxation method. Multigrid method is used to accelerate the speed of convergence and improve the accuracy. The multigrid code is programmed with C language. And the figures of three dimensional film and pressure are given. The result of numerical calculation shows that cone radius R_p and cone depth R_h have a significant impact on the seal performance, and the seal has a good performance with the radius between 0.25 and 0.4 and the depth between 3 and 7.On the other hand, the polar coordinates numerical model and its boundary condition are set up for single type spiral groove (inner, middle, external typed) and double type spiral groove(double typed)with laser surface texturing. Multigrid method is used to solve the numerical model. The multigrid code is programmed with C language. The figures of three dimensional film and pressure for different type spiral grooves are given. The result shows that spiral groove N_g and film-depth H_g have great effect on the seal performance and groove angleαhas great impact on leakage. The seal will have a good performance with N_g between 10 and 18, Hg between 1.5 and 2.5,αbetween 10~0 and 18~0. The conclusion provides valuable reference for design and improvement of hydrodynamic mechanical seal.In a word, this thesis offers theoretical support for the engineering design and application of the mechanical seal surface with the micro-cone shaped and spiral grooves shaped textures by analyzing the hydrodynamic mechanical seal with textured surface.