Numerical study on static and dynamic characteristics of an integral floating ring seal with shallow groove dynamic pressure
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摘要:
建立了浅槽动压整体式浮环密封静力与动力特性多频椭圆涡动求解模型,在验证数值计算方法准确性的基础上,分析了无槽、矩形槽、螺旋槽及T型槽4种结构整体式浮环密封的静力与动力特性,研究了不同结构与工况参数下的整体式浮环密封泄漏量、浮升力以及动力特性的变化规律,分析了槽型对整体式浮环密封转子稳定性的影响,揭示了动压槽型对整体式浮环密封动力特性的影响机理。研究结果表明:泄漏量与浮升力随着偏心率的增加而增大,相较于无槽浮环密封,矩形槽泄漏量最大,T型槽的浮升力最大,为无槽浮升力的434.7%;在同一涡动频率下,矩形槽的有效阻尼最大且为正值,切向气流力与转子涡动方向相反,从而抑制转子的涡动,提高转子稳定。
Abstract:A multi-frequency elliptic vortex solution model for static and dynamic characteristics of the monolithic floating ring seal with shallow groove dynamic pressure was established. On the basis of verifying the accuracy of the numerical calculation method, the static and dynamic characteristics of the integral floating ring seal with no groove, rectangular groove, spiral groove and T-groove were analyzed. The changes of leakage, buoyancy and dynamic characteristics of the integral floating ring seal under different structures and working condition parameters were studied. The influence of groove type on the stability of the integral floating ring seal rotor was analyzed, and the influence mechanism of dynamic pressure groove type on the dynamic characteristics of the integral floating ring seal was revealed. The results showed that the leakage and the lift force increased with the increase of eccentricity. Compared with the non-slotted floating ring seal, the rectangular groove had the largest leakage, and the T-shaped groove had the largest buoyancy, which was 434.7% of that without groove. Under the same vortex frequency, the effective damping of the rectangular groove was maximum and positive, and the tangential flow force was opposite to the rotor vortex direction, which can restrain the rotor vortex and improve the rotor stability.
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表 1 密封模型几何尺寸
Table 1. Dimension of seal model
参数 数值 转子直径ϕr/mm 53.0 浮环内表面直径ϕf/mm 53.2 密封间隙h/mm 0.10 密封环长度L/mm 8.0 密封环高度E/mm 4.5 槽种类数 3 槽个数 16 槽深τ/mm 0.10 槽长l/mm 5.50 表 2 边界条件
Table 2. Boundary conditions
参数 数值及说明 转速/(r/min) 0~ 40000 壁面属性 无滑移绝热 工质 理想空气 湍流模型 标准k-ε 涡动模型 多频椭圆涡动 进口压力/MPa 0.3~0.7 出口压力/MPa 0.1 总温/K 298 偏心率 0~0.7 涡动频率/Hz 40~320 -
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