迷宫螺旋泵和密封的数值分析

THE NUMERICAL ANALYSIS OF LABYRINTH SCREW PUMP AND SEAL

对迷宫螺旋体内的流动提出了若干假定;建立了流动模型;简化了Navior-Stokes方程和连续方程。选用轴及套筒上两组斜交螺纹所围成的蜂窝状空间作为计算区。在计算区内截取两组沿螺纹方向的斜交截面,采用涡量流函数法求出截面上的平面流动解。根据两组截面交线上速度唯一的条件,用一组平面解的已知速度作为给定数据输给另一组平面求出其平面解。如此将两组平面解交替迭代,最后得到的收敛值即该区的空间流动解。将所有蜂窝体内的压力和流量综合起来,就得到迷宫螺旋体的泵特性和密封特性。

The main part of a Labyrinth Screw pump and seal is composed of both threads on the axle and the sleeve, which intersect at an oblique angle. An unit element surrounded by the two sets of threads has been taken as an isolated calculating area. Based on the N-S equation and the continuity equation, the centrifugal force and curvature effect have been neglected. Due to the periodical property along z-direction, it is reasonable to neglect the terms(d/dz)in the equations on the entrance and the middle cross section of the unit element. Thus, the set of equations could be reduced in a simpler form, and the coupling of x-y plane flow with z-direction could be eliminated. Therefore a quasi-state three-dimensional velocity field in the unit element space can be calculated by numerical solutions. Thus the corresponding characteristics of the labyrinth pump and seal may be obtained.