迷宫密封泄漏特性影响因素的研究  

Effects of Gap Pressure Ratio and Rotational Speed on Discharge Behavior of Labyrinth Seal

作　　者：李志刚[1] 李军[1] 丰镇平[1] 

机构地区：[1]西安交通大学叶轮机械研究所,西安710049

出　　处：《西安交通大学学报》2010年第3期16-20,共5页Journal of Xi'an Jiaotong University

基　　金：国家"973"计划资助项目(2007CB707705);新世纪优秀人才支持计划资助项目(NCET-07-0699)

摘　　要：采用标准k-ε紊流模型和三维RANS方程求解方法,数值研究了密封间隙、压比、转速对典型迷宫密封泄漏特性的影响规律.计算分析了典型迷宫密封在3种密封间隙、4种压比和4种转速下的泄漏特性.研究结果表明:用相对流量系数(转动时的流量系数与静止时的流量系数的比值)与速比(周向速度与轴向通流速度的比值)的函数关系表征泄漏量随转速变化的规律时,存在一个临界速比约等于1.0;低于这个临界速比时,转速对泄漏量的影响不明显;高于这个临界速比时,泄漏量随转速的增大而减小,在很高的转速下(6 000 r/min以上),泄漏量至少减小了5.1%;相同间隙下,泄漏系数随着压比的提高而近似线性增加;相同转速下,随着密封间隙的减小,相对泄漏量逐渐降低.The effects of sealing clearance,pressure ratio and rotational speed on the discharge behavior of a typical labyrinth seal are numerically investigated.The Reynolds-averaged Navier-Stokes equations and the standard k-ε turbulent model are adopted to obtain the leakage flow characteristics of the labyrinth seal under the conditions of three sealing gaps,four pressure ratios and four rotational speeds.The relative leakage flow coefficient CD/CD0 and velocity ratio U/Caxare employed to analyze the effects of the rotational speed on the discharge behavior.CD/CD0 is defined as the ratio of leakage rate at rotation to the leakage rate at rest.U/Cax denotes the ratio of the circumferential velocity to the axial flow velocity.Numerical simulation results show that there exists a critical velocity ratio of 1.0.The effect of the rotational speed on the relative leakage flow coefficient can be ignored when the velocity ratio is less than 1.0.If the velocity ratio is greater than 1.0,the relative leakage flow coefficient decreases with the increase of the rotational speed,and the leakage flow rate of the labyrinth seal at the high rotational speed of more than 6 000 r/min decreases by 5.1%.The leakage coefficient increases linearly with pressure ratio at the fixed sealing clearance.In addition,the leakage coefficient decreases with the decrease of gap width at the same rotational speed.

关 键 词：迷宫密封 泄漏特性 数值模拟 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]