Experimental Rotordynamic Coefficient Results for a Load-on-Pad Flexible-Pivot Tilting-Pad Bearing With Comparisons to Predictions From Bulk-Flow and Reynolds Equation Models
Experimental Rotordynamic Coefficient Results for a Load-on-Pad Flexible-Pivot Tilting-Pad Bearing With Comparisons to Predictions From Bulk-Flow and Reynolds Equation Models
复制标题
负载瓦块柔性枢轴可倾瓦轴承的实验转子动力系数结果与整体流动和雷诺方程模型的预测进行比较
DOI：
10.1115/trib2004-64042
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
D. Childs
中科院分区：
文献类型：
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作者：
L. E. Rodriguez;D. Childs
给出了高速、轻载、瓦上负载、柔性枢轴可倾瓦轴承的实验动态刚度系数结果。结果表明，直接动刚度系数的实部是激励频率的二次函数。这种频率依赖性可以通过附加质量系数很好地建模，并且所得的 [M]、[K] 和 [C] 矩阵模型与频率无关，而传统的 [K] 和 [C] 模型则与频率相关。由附加轴瓦自由度（包括轴瓦惯性和腹板力矩刚度）引入的动力学以及润滑油膜中流体惯性的影响部分解释了这种频率依赖性。将实验结果与基于以下模型的数值预测进行比较：(i) 雷诺方程，以及 (ii) 保留时间和对流流体惯性项的纳维-斯托克斯 (NS) 方程整体流动模型。 NS 整体流动模型结果与实验动态刚度结果（包括附加质量项）具有更好的相关性。两种模型都低估了整个激励范围内测量的附加质量系数；然而，它们对于高达同步频率的激励频率来说已经足够了。通过使用雷诺方程或整体流 NS 模型将质量矩阵添加到反作用力模型中，可以消除使用 [K] 和 [C] 模型预测的频率依赖性，从而大大加快转子轴承系统阻尼特征值的计算速度。版权所有 © 2004 ASME
Experimental dynamic-stiffness-coefficient results are presented for a high-speed, lightly loaded, load-on-pad, flexible-pivot tilting-pad bearing. Results show that the real part of the direct dynamic-stiffness coefficients are quadratic functions of the excitation frequency. This frequency dependency is modeled well by an added-mass coefficient, and the resultant [M], [K], and [C] matrix model is frequency-independent versus a conventional [K] and [C] model that is frequency dependent. The dynamics introduced by the additional pad degrees of freedom (including pad inertia and web moment stiffness) and the effects of fluid inertia in the lubricant film account for part of this frequency dependency. Experimental results are compared to numerical predictions from models based on: (i) the Reynolds equation, and (ii) a Navier-Stokes (NS) equations bulk-flow model that retains the temporal and convective fluid inertia terms. The NS bulk-flow model results correlate better with experimental dynamic stiffness results, including added-mass terms. Both models underestimate the measured added-mass coefficients for the full excitation range; however, they do an adequate job for excitation frequencies up to synchronous frequency. The frequency dependency predicted by using a [K] and [C] model can be removed by adding a mass matrix to the reaction-force model with either a Reynolds equation or a bulk-flow NS model, with a very considerable speed up in calculation of damped eigenvalues for rotor-bearing systems.Copyright © 2004 by ASME