激光加工多孔端面机械密封中空化边界条件的比较

Comparison of Cavitation Boundary Conditions in Analyses of a Laser Surface Textured Mechanical Seal

建立了激光加工多孔端面机械密封(LST-MS)的动压分析理论模型,在Half-Sommerfeld、Reynolds和JFO等3种不同空化边界条件下应用有限元法求解了端面流体膜压的Reynolds控制方程,研究了微孔结构参数及操作条件对端面无量纲平均动压的影响规律,并对上述空化算法的计算速度和精度进行了比较。结果表明,在一般情况下,采用Reynolds和JFO空化边界条件具有十分接近的预测精度,但是前者的预测速度明显优于后者,而采用Half-Sommerfeld空化边界条件预测精度则很差,建议此时采用Reynolds空化边界条件;对于不能采用Reynolds空化边界条件的情况,则建议采用JFO空化边界条件进行预测分析。

A theoretical analysis model of film hydrodynamic pressure between the two faces was developed for a laser surface textured mechanical seal （LST-MS）. Finite element method was used to solve Reynolds equation respectively under the different cavitation boundary conditions of Half-Sommerfeld, Reynolds and Floberg or JFO. The effects of micro-pore geometrical parameters and operating conditions on dimensionless average dynamic pressure between the two faces under the different cavitation boundary conditions were studied. The results show that the prediction accuracies are nearly the same when the boundary conditions of Reynolds and JFO are used, but the former predicts more faster than the latter. The prediction error is very large when Half-Sommerfeld boundary condition is used. So it is suggested that the Reynolds cavitation boundary condition is generally used for numerically solving Reynolds equation controlling the film pressure of a LST-MS, otherwise the JFO boundary condition is used when the effects of face temperature and/or phase states of the fluid film between the two faces are considered.