Aerodynamic resistance of a brush seal was mainly studied. The velocity distribution along three specified lines was presented. By considering the pressure differential, Reynolds number and Euler number (Eu) were modified. The effect of geometric arrangements and pressure differentials on Eu and leakage were analyzed. Two correlations were fitted based on the numerical results. The results reveal the velocity distribution is almost flat, asymmetric along the specified lines. The velocity increases and decreases almost linearly at centerlines. Eu decreases gradually less with the increase of pressure differential and trends towards a fixed value. A larger Eu indicates stronger resistance but not necessarily less leakage. Finally, two fitted correlations are developed and one is exponential to the row number fits better.

Brush seal is a novel type contact seal, and it is well-known due to its excellent performance. However, there are many intrinsic drawbacks, such as hysteresis, which need to be solved. This article focused on modeling hysteresis in both numerical way and analytic way without pressure differential. The numerical simulation was solved by the finite element method. General contact method was used to model the inter-bristle contact, bristle-rotor contact, and bristle-backplate contact. Bristle deformation caused by both vertical and axial tip force was used to validate the numerical model together with reaction force. An analytic model in respect of the strain energy was created. The influence of structure parameters on the hysteresis ratio, with the emphasis on the derivation of hysteresis ratio formula for brush seals, was also presented. Both numerical model and analytic model presented that cant angle is the most influential factor. The aim of the article is to provide a useful theoretical and numerical method to analyze and predict the hysteresis. This work contributes the basis for future hysteresis investigation with pressure differential.

To reveal the wear law of parabola-shaped and arc-shaped finger seals (FSs), the wear characteristics of parabola-shaped and arc-shaped FSs were studied in this paper. Firstly, a formula for calculating the contact stress of finger boot / rotor is established according to bootlace theory. Secondly, based on the mathematical model of wear rate in related literature, the influence of structural parameters on FS wear was investigated. Results showed that when the rotor speed is less than 1700r/min, the contact stress of the parabolic FS is less than that of the arc-shaped FS; when the rotation speed is greater than 1700r/min, the contact stresses of the parabolic and arc-shaped FSs increase rapidly. Furthermore, when the speed is greater than 4000r/min, the contact stresses of the two structures are similar. When the rotor speed is less than 3000r/min, the trends of the wear rate of the parabolic and arc-shaped FS structures are irregular; when the rotor speed is greater than 3000r/min, the wear rate of the parabolic FS structure is greater than the arc-shaped FS, and the wear rates of the two structures increase exponentially. Our results provide theoretical basis and reference for the wear performance of PFS and AFS.