仿鸟翼微列螺旋槽干气密封性能分析与选型

为改善单向螺旋槽干气密封在高速条件下存在的泄漏率高、稳定性欠佳等问题,提出一种仿鸟翼微列螺旋槽端面干气密封结构.基于气体润滑理论,建立仿鸟翼微列螺旋槽的端面几何模型和数学模型,数值分析周向开槽宽度和径向开槽宽度对轴向气膜刚度和泄漏率等密封特性参数的影响规律,给出仿鸟翼微列螺旋槽主要结构参数的优选值范围.在不同压力、线速度和膜厚条件下对比分析仿鸟翼微列螺旋槽干气密封与普通螺旋槽干气密封的开启力、轴向气膜刚度、泄漏率和刚漏比等密封特性,给出不同工况条件下两种型槽干气密封的密封性能等值线图.结果表明:在高速低压条件下,相较于单向螺旋槽干气密封,仿鸟翼微列螺旋槽干气密封的密封性和稳定性都有显著提升,其轴向气膜刚度增幅达到30%,泄漏率降幅达到10%.仿鸟翼微列螺旋槽干气密封性能等值线图的提出可为其工程选型及优化设计提供指导和借鉴.

Performance Analysis and Selection of a Bionic Bird Wing Multi-Array Spiral Groove Dry Gas Seal

A new type of bionic bird wing multi-array spiral groove dry gas seal was introduced to solve the problems that unidirectional spiral groove dry gas seal had poor operational stability and high leakage rate when it operated at high speed. With the gas lubrication theory,geometric model and mathematical model of bionic bird wing multi-array spiral groove were set up,and a series of simulations were carried out to analyze the influence of groove width in circumferential and radial direction on sealing performance like axial gas film stiffness and leakage rate,and optimization of the main geometric parameters of bionic bird wing multi-array spiral groove was demonstrated. Comparative analysis of different sealing performance like opening force,axial gas film stiffness,leakage rate and stiffness-leakage ratio between bionic bird wing multi-array spiral groove dry gas seal and common spiral groove dry gas seal in different outer pressure,linear velocity and film thickness was made,sealing performance contour map of these two types of grooves in different working conditions was presented. Numerical results show that sealing performance and stability of bionic bird wing multi-array spiral groove dry gas seal were much better when compared to unidirectional spiral groove dry gas seal at the condition of high speed and low pressure. The growing rate of axial gas film stiffness was more than 30%,the reduction amplitude of leakage rate was more than 10% in detail. The sealing performance contour map of bionic bird wing multi-array spiral groove dry gas seal provided a reference for the model selection and optimization design in engineering.