迷宫密封流场和泄漏量的数值分析与研究

摘要

应用Fluent计算软件采用标准k-ε湍流模型求解迷宫密封三维流场,研究了涡动转子在不同压比和偏心位移下密封腔室内的流场特性.进一步讨论了转子涡动速度、进出口压比和偏移位移对迷宫密封泄漏量的影响.研究发现,涡动速度越大对密封泄漏量的影响也越大,随着涡动速度的增加密封泄漏量降低；不同的进出口压比使密封中流体的轴向流速不同,当轴向流动速度达到跨音速以上时,密封泄漏量特性发生明显变化,此时密封泄漏量达到最大；密封转子的径向偏移量会增加密封的泄漏量.为了能在工程实际中更快更好地计算迷宫密封泄漏量,进一步修正和完善了Egli密封泄漏量经验计算公式,完善后的计算公式对迷宫密封工程设计及运行具有一定的意义.%The three-dimensional flow flied model of labyrinth seals was solved to obtained the leakage of the flow with the standard k-s turbulence model, utilizing a general Computational Fluid Dynamics ( CFD) program Fluent, and the characteristics of the flow flied with the whirling rotor was studied in different situation, such as eccentrics and pressure ratios. In the paper, the effects of the whirling speed, outlet/inlet pressure ratio and eccentric displacement on the leakage of the labyrinth seal were analyzed. It was found that when the whirling speed was improving,the leakage was decreasing. And the different pressure ratios made the different axial speeds of the flow. When the speed was transonic or faster,the leakage reached the maximum. In addition,the bigger radial displacement of the eccentric caused the higher leakage of the seal. Base on the CFD results, the Egli 's empirical formula of the leakage on the labyrinth seals was modification and improvement. And the new empirical formula is useful to calculate the leakage with the labyrinth seal designing or rotating machinery operation.