螺旋槽液膜密封热流体动力润滑性能分析

基于热流体动力润滑理论，建立了基于质量守恒和能量守恒的螺旋槽机械密封准三维热流体动力模型，采用有限单元法同时求解跨膜平均能量方程和动静环热传导方程，并迭代求解广义雷诺方程和温度方程获得了液膜压力、温度和密封环的温度分布。对比分析了不同螺旋槽参数下密封热流体动力润滑(THD)和流体动力润滑(HD)的密封特性。结果表明：高黏度下润滑液膜的热效应不可忽略。与THD模型相比，HD模型过高估计了开启力和摩擦系数，但低估了密封泄漏率。以开启力为目标，THD模型下的最优槽深小于HD模型下的值；大的槽坝比和螺旋槽个数均会增加密封泄漏率；螺旋槽结构对摩擦系数的影响规律与开启力趋势相反；大槽深和大槽坝比有助于降低液膜和密封环的温度。

Analysis of thermohydrodynamic lubrication performance of spiral-grooved liquid film seals

Based on the thermohydrodynamic lubrication theory, a quasi three-dimensional thermohydrodynamic model of the spiral-grooved mechanical face seals considering the mass and energy conservation was established. The finite element method was applied to simultaneously solve the average energy equation of the cross film and the heat conduction equations of the rotor and stator. The equation and temperature equations obtained the film pressure, temperature, and temperature distribution of the seal ring. The sealing performance of THD and HD under the different spiral-grooved parameters was compared. The results show that the thermal effect of high viscosity fluid film can t be neglected. Compared with the THD model, HD model overestimates the opening force and friction coefficient but underestimates the leakage rate. When taking the opening force as the objective, the optimal value of the groove depth from THD is smaller than one from HD model. The increase in the groove-dam ratio and the groove number leads to the rise in the leakage rate of the seal. The influence of the spiral-grooved parameters on the friction coefficient is opposite to the opening force. The increase in the groove depth and the groove-dam ratio is help for reducing the temperature rise of the liquid film and the seal rings.