刷式密封刷丝变形与振动特性实验

doi:10.7527/S1000-6893.2019.23364

Abstract

Abstract: The problem of the leakage and bristle fracture produced by the bristle deflection and oscillation of brush seals is very prominent. In this paper, the theoretical model of the bristle deflection and oscillation of brush seals is analyzed, the device of observation experiment for the bristle deflection and oscillation characteristics of brush seals is designed. Experimental pieces of brush seals for low hysteresis at three circumferential inclination angles are designed and processed. Moreover, the bristle axial deflection characteristics, bristle blow down effect, bristle stratification, and bristle oscillation characteristics are experimentally observed and studied, revealing the bristle movement of brush seals. The results show that the axial deflection of the bristle tips increases linearly with the increase of the pressure ratio when the inlet-to-outlet pressure ratios are between 1.5 to 4, and the circumferential inclination angles have little effect on the bristle axial deflection. The blow down effect of the front row is significantly stronger than that of the rear row. Under the research conditions of this paper, the maximum amount of bristle blow down of brush seals with circumferential inclinations angles of 50°, 55° and 60° is 0.60, 0.45 and 0.34 mm respectively. With the increase of the circumferential inclination angle, the blow down effect is gradually weakened. Under the influence of the air force, brush seals bristle produces axial deflection, and the bristle tips are subject to the unequal axial frictional force of the rotor surface. Brush seals bristle produces unequal axial deflection, resulting in large gaps inside the bristle pack, and forming bristle stratification. The bristle oscillation mainly occurs in the region where the bristle density is relatively loose, and with the increase of the pressure ratio, the displacement of the bristle tip is oscillating. Its amplitude in the axial direction is greater than that in the circumferential direction.

Key words: brush seals, bristle deflection characteristics, blow down effect, stratification, oscillation characteristics

CLC Number:

V231

SUN Dan, DU Chenyu, LIU Yongquan, ZHAN Peng, XIN Qi. Experiment on bristle deflection and oscillation characteristics of brush seals[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2020, 41(10): 123364-123364.

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Experiment on bristle deflection and oscillation characteristics of brush seals

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