Numerical Analysis Of Mechanical Seal With Cylindrical Micro-Pores On Surface

Fluid hydrodynamic analysis of mechanical seals with cylindrical micro-pores on the surface has been presented in this thesis. The effect of structure and operating parameters on the liquid film pressure between seal faces has been researched by the finite difference method. Based on this, the seal performance of mechanical seals with cylindrical micro-pores on the surface has been systematically studied by theoretical analysis and numerical simulation. The main contents and achievements are summarized as follow:1) A theoretical model has been developed to investigate hydrodynamic effect of the mechanical seals with cylindrical micro-pores on the surface. By means of variable dimensionless steps, numerical analysis and parametric investigation have been performed to obtain liquid film pressure by the finite difference method. Meanwhile, three dimensional liquid film pressure distributions over the pore column can be achieved by computer program MATLAB. The average liquid film pressure can be calculated as a function of the structure and operating parameters. It was found that the average liquid film pressure increases with increase of the rotational speed, liquid viscosity and liquid pressure and reduction of the seal clearance. On the other hand, the effect of pore density and depth over diameter ratio is very significant to the average liquid film pressure. Optimum values of these parameters can maximize the average pressure.2) The sealing characteristics of the mechanical seals with cylindrical micro-pores on the surface have been studied in detail. A formula used as calculating frictional torque between seal faces has been derived. Effect of structure parameters on sealing characteristics has been analyzed theoretically. Results show that optimum structure parameters maximize the sealing property as the radius of the micro-pores is constant.3) Effect of operating parameters on sealing characteristics has been derived theoretically. Results show that optimum operating parameters maximize the sealing property as the radius of the micro-pores is constant.In brief, by means of numerical analysis on mechanical seals with cylindrical micro-pores on the surface, the optimum structure parameters have been obtained, which establishes the theoretical base to the further study.