Fluid-Structure Analysis of a Hybrid Brush Seal

A multidisciplinary mathematical model of a hybrid brush seal is developed. Gas flow pressure distributions and lifting forces acting on the seal compliant elements depend on current positions of the latter ones and vice versa. Seal operating clearance and leakage are obtained by means of the iterative approach for solving static fluid-structure interaction problem. A model comprising rigid pad attached to elastic support with the equivalent stiffness matrix is used for calculation of seal compliant element displacements. A model of flow in the clearances between the pads and the shaft based on 2D Reynolds equation is used for calculation of gas lifting force acting on pads. Both simplified models are verified by comparing with results obtained by means detailed 3D simulations. It is shown that the circumferential inclination of pads has significant influence on the gas lifting force generated under the pads.