Abstract:Based on the porous media model, numerical simulation was performed to research the leakage flow characteristics of brush seal with three different kinds of groove, including conventional brush seal, rectangular brush seal and airfoil brush seal. Results indicate that,compared to conventional brush seal, the rectangular brush seal’s hysteresis is not been improved. The airfoil brush seal’s hysteresis is reduced greatly,but its leakage is increased a lot at the same time.In order to improve the performance of low hysteresis brush seal, the concept of backplane axial clearance was put forward,and the influence of backplane axial clearance on the leakage flow characteristics of low hysteresis brush seal was researched.The results indicate that,under the certain compression ratio,the leakage flow rate is proportional to the axial clearances,while the leakage increasement is inversely proportional to the axial clearances,and both of the changes can be found more obviously when the axial clearance is small.Compared with rectangular brush seal, the axial clearance seal’s pressure values at backplate is reduce a lot with the increase of the axial clearance except at protection height region,and the most obvious pressure drop effect can be obtained when the axial clearance is increased from 0 to 0.1 mm.