Effects of Tensor Closure Models and 3-D Orientation on the Stability of Fiber Suspensions in a Channel Flow
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摘要: 应用3种不同的纤维方向张量封闭模型,数值模拟了纤维悬浮槽流的流动稳定性问题,从而研究封闭模型和纤维的三维取向分布对稳定性分析的影响.结果发现,采用3种不同封闭模型所得到的流动稳定特性与纤维参数之间的关系是相同的,但采用三维混合封闭模型时,由于纤维的取向与流向的偏差程度较大,所以纤维对流动的不稳定性具有最强的抑制作用.而采用二维混合封闭模型时,由于纤维在平面取向条件下,其轴线整体上趋于呈流向排列,使得对流体的作用削弱,导致纤维对流动不稳定性抑制的作用最弱.Abstract: Three different kinds of closure model of fiber orientation tensors were applied to simulate numerically the hydrodynamic stability of fiber suspensions in a channel flow. The effects of closure models and three-dimensional (3-D) orientation distribution of fibers on the results of stability analysis were examined. It is found that the relationship of the behavior in hydrodynamic stability and the parameter of the fiber given by all the three models are the same. However, the attenuation of flow instability is most distinct using 3-D hybrid model because the orientation of the fiber departures from the flow direction, and least apparent using its 2-D counterpart for that the fibers show a tendency towards alignment with the flow direction in this case.
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Key words:
- fiber suspension /
- hydrodynamic stability /
- channel flow /
- closure model /
- fiber orientation
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