Analysis of Wear Characteristics of Elliptic Arc Finger Seal Based on Fractal Theory

doi:10.3901/JME.2023.03.144

Abstract

Abstract: As a new sealing technology with wide application potential, the wear characteristics of finger seal (FS) have been a research focus. Based on fractal theory and considering the contact relationship between the surfaces of the FS and the rotor, the contact coefficient between the FS and the rotor is introduced into the area distribution expression of contact point, a wear fractal model of the FS is established, and a mathematical model of FS energy density is built to characterize the wear energy transformation and consumption process. The concept and structure of elliptic arc finger seal (EAFS) are proposed, and the performance of EAFS is compared with that of arc finger seal (AFS) and involute finger seal (IFS). Results show that the contact coefficient is always less than but close to 1, the two surfaces are always in contact with each other, and the contact is very close, the contact coefficient is thus valid. Compared with the classical experimental data, the wear fractal model is consistent with the change trend and the order of magnitude, indicating the feasibility of the wear fractal model of FS. There is an optimal value (D=1.3) of fractal dimension, which can minimize the volume wear rate and maximize the energy density simultaneously. Results further reveal that reducing the characteristic size can effectively reduce the volume wear rate and increase the energy density. Comparing to AFS and IFS, EAFS is more suitable for sealing parts with larger radial runout, bigger pressure difference and higher rotating speed.

Key words: finger seal, fractal theory, wear rate, energy density, elliptic arc

CLC Number:

TB42

LEI Junjie, LIU Meihong, HU Xiangping, WANG Juan, WANG Xueliang. Analysis of Wear Characteristics of Elliptic Arc Finger Seal Based on Fractal Theory[J]. Journal of Mechanical Engineering, 2023, 59(3): 144-157.

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