Analysis of Fluid Film Seals - Consideration of Non-Newtonian Fluid and Anisotropic Slip

• Main Authors: Hong, Wei-Jhe, 洪唯哲
• Other Authors: Chang, Kuo-Ming
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/eppka7

碩士 === 國立高雄科技大學 === 機械工程系 === 107 === This paper analyzed the liquid film lubrication between the rotor and the stator in the non-contact spiral groove mechanical seal. Considering the anisotropic slip and rheological effects, the modified Reynolds equation is derived, and the finite element method is used to solve the seal performance of load, leakage and friction torque under different variables(groove depth; slip direction and length; film thickness; rotating speed; flow behaviour index). The linear perturbed method is used to linearize the modified Reynolds equation, and the dynamic equation is solved from the zero-order steady-state equation, and then the dynamic coefficient of the shaft seal steady state is calculated. As a result, there is a slip phenomenon in the shaft seal, which causes the overall shaft seal load to decrease, the leak rate to increase, and the friction torque to decrease. When slipping in different directions, it is affected by the Poiseuille flow and Couette flow correction factor. After flow behaviour index is less than 0.9, the seal performance does not change much, and the seal performance changes greatly when it is higher than 1.05. Slip had the greatest impact on the leakage rate and the pressure needed to rise to reduce the leakage rate. The stiffness coefficient is the same as the load growth trend, and the damping coefficient is the same as the friction torque growth trend.