The Inter-Bristle Pressure Field in a Large-Scale Brush Seal
The Inter-Bristle Pressure Field in a Large-Scale Brush Seal
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大型刷式密封中的刷毛间压力场
DOI：
10.1115/1.4055458
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Bowen J
中科院分区：
文献类型：
--
作者：
Bowen J
刷式密封有望改进广泛使用的迷宫式密封，以调节涡轮机泄漏。通过在旋转方向上成角度并弯曲以适应转子偏移的密集排列的细钢丝刷毛的静态环来提供对流动的增强阻力。通过对大型刷式密封的试验研究，探讨了在多种间隙条件下刷组内部及周围压力场与密封泄漏特性的间接关系，从而加深了对刷式密封流体动力学行为的认识。控制泄漏行为的控制参数从大间隙的压力比过渡到在线配置的压力载荷。在所有情况下，一旦达到最大水平的刷毛吹扫和压缩，泄漏流量收敛到一个渐近值。对于这两种间隙配置，这发生在对应于压力轴向分布收敛的压力比处;对于具有压降的线-线配置，注意到等效行为。对于在线刷式密封，随着压降的增加，泄漏行为和刷毛间压力场的变化相对较小。这表明刷式密封性能受刷毛吹扫变化的影响大于刷丝束压实。
Brush seals promise improvements to the widely used labyrinth seal in regulating turbomachinery leakages. Enhanced resistance to the flow is provided by a static ring of densely packed fine wire bristles that are angled in the direction of rotation and flex to accommodate rotor excursions. A large-scale brush seal was constructed to study the leakage characteristics indirect relationto the pressure field within and surrounding the bristle pack for multiple clearance conditions, therefore developing the understanding of brush seal fluid dynamic behavior. The governing parameter controlling leakage behavior transitioned from pressure ratio for a large clearance, to pressure load for a line-on-line configuration. In all cases, leakage flow converged to an asymptotic value once maximum levels of bristle blow-down and pack compaction were attained. For both clearance configurations, this occurred at a pressure ratio corresponding to that at which axial distributions of pressure converged; equivalent behavior was noted for the line-on-line configuration with pressure drop. Comparatively small changes were experienced in leakage behavior and in the interbristle pressure field with increasing pressure drop for the line-on-line brush seal. This indicated that brush seal performance is more influenced by changes in bristle blow-down than bristle pack compaction.