Buoyancy effect of front plate perforated brush seal based on transient fluid-solid interaction

To tackle the buoyancy effect of bristles in traditional brush seal (TBS) induced by airflow, which leads to bristles disturbance instability, the construction of front plate perforated brush seal (FPBS) was proposed. Based on the Arbitrary Lagrange-Eulerian fluid-solid interaction method, three-dimensional transient solution model of the floating disturbance effect of FPBS was established. The leakage characteristics and flow field velocity characteristics of the FPBS were analyzed, and the influence of different structural parameters of the suppression disturbance (SD) hole on the buoyancy effect was researched. Additionally, the bristle tip deformation characteristics were further quantitatively investigated. The results indicated that the FPBS reduces bristles bending deformation caused by airflow by setting SD hole in front plate. This novel structure can effectively suppress the bristles buoyancy effect and improve the sealing performance. Compared to TBS, which is prone to the buoyancy effect, increasing the angle, diameter, and height of the SD hole can effectively reduce the leakage rate. When the SD hole diameter reaches 2.00 mm, the leakage rate decreases by 19.57%. The bending deformation of the bristles induced by the airflow can be effectively reduced by setting the SD hole in the front plate. When the angle of the SD hole is 60°, the diameter is 2.00 mm, and the height is 5.10 mm, the average deformation of the bristle tip can be reduced by 41.39–49.07% compared with the TBS.