Numerical research on hysteresis characteristics of full contact brush seals under differential pressure

DOI:	10.11809/bqzbgcxb2024.01.023
Keywords:	brush seal; hysteresis characteristics; geometric parameters; hysteresis energy; contact force
Abstract:	Problems caused by hysteresis like leakage, frictional wear and flow heat transfer are obvious in brush seals. Brush seal numerical models have characteristics such as many contact pairs, bristle large deformation interaction. Hence, the problems of brush seal numerical models are high degree of non linearity and poor convergence. Brush seal hysteresis numerical model, based on the finite element software ABAQUS, is built. This numerical model is with the contact between bristles, bristles and backing plate, bristles and rotor introduced. Damping is brought in to improve the numerical convergence. Based on the comparison between numerical, experimental and theoretical results, the study is conducted to demonstrate the influential extent on the hysteresis characteristics of brush seal and the maximum value of the contact force, which have a close connection with some specific statistics such as the brush seal free length, the bristle diameter, the bristle cant angle, and the pressure differential. Investigation results show that with the increment of pressure differential and bristle diameter, brush seal hysteresis becomes stronger. While with the bristle cant angle increases, brush seal hysteresis becomes weak. The influence of bristle free length on brush seal hysteresis is limited. Bristle diameter is the key factor in determining the contact force between bristles and the rotor. And bristle cant angle has a certain effect on maximum contact force. The above study provides a theoretical basis for analyzing the hysteresis characteristics of brush seals and gives a reference for reducing the hysteresis characteristics.
Published:	2024-01-28
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