CFD study of radial and tangential forces in two-annular seals

Currently, as is known from the practical experience of using multi-annular seals, the cavities connecting the annuluses are one of the elements that significantly affects on the static and dynamic stability of the shaft. In the paper, the task is to analyze the influence of the geometric parameters of the connecting cavity on the magnitude and direction of the total radial hydrostatic force due to the eccentricity of the axis of the shaft and the housing. Moreover, the paper is aimed at studying that influence on the magnitude and direction of the total tangential force caused by the whirl and the own rotation of the shaft. There have been compared the distributions of the friction factors along the lengths of the two-annular seal three designs: the basic design (TwAS-BD), the design with a radial groove on the outer radius of the housing (TwAS-GOR), and the design with a radial groove on the inner radius of the housing (TwAS-GIR). There have been studied the radial and tangential forces in the design with a diffuser taper at the second annulus (TwAS-D).