Theoretical and Experimental Investigation on the Bristle Contact Deflections Characteristics of Brush Seals Based on ALE Fluid-structure Interaction Method

doi:10.3901/JME.2020.09.170

Abstract

Abstract: The problem of the leakage and bristle fracture produced by the bristle deflections of brush seals is very prominent. Existing fluid-structure interaction method of brush seals has difficulty in calculating for grid distortion caused by bristle contact deflections. Three-dimensional transient computational model for bristle contact deflections characteristics of brush seals is built based on arbitrary Lagrange-Euler(ALE) fluid-structure interaction method, observation experimental device for bristle contact deflections characteristics of brush seals was constructed, basic type, low-hysteresis type with pressure chamber and without pressure chamber three test pieces are processed, based on theoretical computation which is verified with experimental results, effects of pressure ratio and structure of brush seals on the bristle contact deflections and stress are predicted, hysteresis effects of three brush seals are compared quantitatively based on contact friction. The research results show that ALE fluid-structure interaction method can solve the problem which is difficult to calculate by traditional numerical method of brush seals, and can accurately calculate the flow field characteristics and the bristle contact deflections characteristics of the brush seals; Under the conditions here, the leakage and the bristle axial deflections of the low-hysteresis type without the pressure chamber are the largest, and the contact stress of the fixed end of the brush wire is also the largest, the leakage and the bristle axial deflection of the basic type are the smallest, but the hysteresis effect is the strongest, the low-hysteresis type of the pressure chamber can weaken the bristle deflection and hysteresis effect, but the contact stress of the last row of brush wire and the backing plate is the largest, and the brush wire is prone to fatigue fracture at this position due to stress concentration.

Key words: brush seals, ALE fluid-structure interaction method, contact deflections characteristics, contact friction

CLC Number:

TK263

SUN Dan, DU Chenyu, LIU Yongquan, ZHAN Peng, XIN Qi. Theoretical and Experimental Investigation on the Bristle Contact Deflections Characteristics of Brush Seals Based on ALE Fluid-structure Interaction Method[J]. Journal of Mechanical Engineering, 2020, 56(9): 170-180.

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