Influences of geometric parameters on leakages and bristle tip forces in brush seals

Based on a type of three-dimensional slice model of brush seals in combination with the CFD method, the aerodynamic forces applied onto bristles were analyzed and simplified to the concentration of a smaller amount of point forces. Bristle tip forces and torques caused by aerodynamic forces were quantitatively investigated using torque rebalance and linear superposition principles. A test rig and a brush seal ring were applied to verify the related theory in test. Orthogonal tests were used to study the influences of the bristle length, inter-bristle spacing, bristle row number, lay angle, bristle diameter and protection clearance on leakage rates, aerodynamic forces, bristle tip forces and torques. Results indicate that the calculated total leakage rate and torques agree with the test data, the error at each point is less than 20%. The influences of bristle diameter, inter-bristle spacing, protection clearance, bristle row number on total leakage rate are very significant, and influence of the lay angle on torques are very significant too.