Numerical Analysis of Leakage Performance of Brush Seal Based on a 2-D Tube Bank Model and Porous Medium Model Considering the Effect of Compressible Gas

Abstract

This paper presented a formula for calculating the resistance coefficient of porous medium model of brush seals considering the effect of gas compressibility. Firstly, the 2-D tube bank model is used to calculate the axial resistance coefficient of brush seals. Secondly, the feasibility of the method is validated according to the existing experiment results. The validation results show that this formula is effective for brush seals. Lastly, the pressure distribution and leakage rate of the test brush seal are analyzed. With the presented porous medium model, the pressure drop through the bristle is computed, and the effect of groove of the back plate is addressed. The pressure drop is mainly concentrated on the downstream side of the bristle pack. The groove in the back plate can keep the pressure balance of the bristles back, causing the recovering of the pressure in the last row of bristles. The leakage rate of porous medium model is higher than the 2-d tube bank model, because the 2-D tube bank model only considers the leakage rate of the zone of the fence height. The rotation speed has a little effect on the reduction of the leakage rate.