基于鸟翼轮廓的干式气体密封仿生型槽设计

为解决目前干式气体密封存在的开启力与气膜轴向刚度不足,易出现磨损与失稳等问题,本文尝试将仿生学理念引入干式气体密封技术中,通过分析典型飞鸟的羽翼轮廓差异对其飞行状态与能力的影响,定义轮廓外形几何特征参数,运用几何重构法在现有干式气体密封的典型型槽即螺旋槽的基础上构建仿生型槽,提出新型仿生型槽干式气体密封密封.基于气体润滑理论,在建立仿生型槽干式气体密封的几何模型和端面气膜压力控制方程的基础上,采用有限差分法对仿生型槽干式气体密封进行数值模拟研究,分析了仿生型槽的主要几何结构参数对密封性能的影响规律.结果表明：相较于典型螺旋槽干式气体密封,通过合理设置仿生型槽干式气体密封的端面型槽的几何结构参数值,其开启力、气膜刚度等密封性能参数在一定范围内有所提升;干式气体密封的仿生设计具有重要的实际意义.

Design of a Biomorphic Groove Dry Gas Seal Based on Bird Wing Outlines

In order to solve the problems of a dry gas seal (DGS), such as the opening force or the axial gas film stiffness between two faces is insufficient and face wear or instability occurs sometimes, the concept of bionic design for a DGS is introduced in this paper. After the effects of various flying wings of typical birds on their flying ability were analyzed and the geometric feature parameters of the wing outlines were presented, a biomorphic groove has been invented based on the classic type of a DGS with spiral grooves onto its one of two sealing faces (S-DGS) and by use of the geometric reconstruction technique. Then a new type of a biomorphic groove dry gas seal (B-DGS) was presented. The geometric model of such a B-DGS was presented. The Reynolds equation for controlling gas film pressure between two sealing faces of a B-DGS or a S-DGS was solved by use of the finite difference method. The variations of sealing performance with the major geometric parameters of a biomorphic groove were simulated. The comparisons of sealing performance parameters, such as the opening force, gas film stiffness, between a B-DGS and a S-DGS were made under the same operating conditions. The results show that the sealing performance of a B-DGS will be improved to some extend compared to that of a S-DGS when the geometric parameters of biomorphic grooves are set reasonably, then the face lift-off ability during start-up or shut-down and the stability of such a B-DGS will be promoted. The bionic design of a DGS is of practical significance.