Study Of Flow And Mechanical Characteristics Of Brush Seals Based On Fluid-ructure Interaction

Brush seals are key components in aircraft engines,an contact dynamic seal with good sealing performance,establisheing the fluid-structure interaction numerical model more appropriate to practical applications,investigations on the flow and mechanical characteristics have important significance to improve the brush seals performance.This paper established the brush bristle-beam theory model,and studied the wire brush bristle-beam bending deformation and bending stress theory.By using fluid dynamics and structural dynamics methods,the flow and mechanical characteristics in brush seals were predicted using a 3D computational model depending on two-way fluid-structure interaction and moving grids techniques.On the basis of verifying the accuracy of the model,the relationships between pressure,velocity,leakage law and the main structure parameters were studied,respectively.Based on above study,the leakage formulas of brush seals were derived.The results show that with the increasing of the height of backing plate fence,the clearance of brush wire and the axial clearance between brush bristle and back plate,the leakage factor rises firstly and then reaches a stable value.The law of bristle deflections,the stress and hysteresis characteristics were predicted of mechanical characteristics in brush seals.The results show that the bristle deflections caused by axial flow impact is oscillating gradually,and the maximum stress of the bristle root is also oscillating gradually depending on the bristle deflections.Some new kind of brush seals are given for structure optimization in this paper.The first one is a new kind of brush seals with the ability of radially regulation.The second one is a new brush seals with elastic support structure in bristle pack.The third one is a backing plate with annular convex platform structure.