Effects of Structure Elasticity on Leakage and Rotordynamic Coefficients of Floating Ring Seals

To study the effects of elastic deformation of floating ring seals on hydrodynamic forces under high pressure, a coupled model of flow field in the seal clearance and elastic structure of the floating ring is established, by making use of bulk flow model, finite element method and displacement-displacement coupled method. By comparison with reference and commercial software result, the coupled model and calculation procedure are proved to be accurate. The results show that structural elasticity of floating ring seals results in narrowing clearance height with 21.43% deformation at the seal entrance and leakage reducing 19.2%. Direct stiffness decreases and coupled stiffness increases relatively when structural elasticity is taken into consideration. With eccentricity ratio increasing, the effect of structural elasticity becomes much evident. Elastic deformation of floating ring seals results in the decrease of the critical speed of rotor decreases and the increase of vibration amplitude.