4∶1粘弹性收缩流动中纤维取向研究

摘要

利用纤维生成算法，研究了4∶1粘弹性收缩流动中的纤维取向。直接在流场中生成纤维，通过求解Jeffery方程，得到纤维在流场中的取向状态。结果表明在4∶1平板收缩流中，在靠近壁面且远离拐角的区域，流场中主要是剪切作用占主导地位，而纤维呈现周期性旋转状态；在接近中轴线的位置，流场中转变为拉伸作用占主导地位，纤维沿单轴拉伸；在在上游拐角区域和收缩入口处，流动相对复杂，纤维的取向也相对复杂，因为流动以旋转为主，所以纤维取向也随着出现不规则旋转。%The algorithm of fiber generation is used to study fiber orientation in 4∶1 viscoelastic planar contraction flow. The fibers are generated directly in the flow field,and the fiber orientation state in the flow field is obtained by solving Jeffery equation. The results in 4∶1 planar contraction of fibers orientation state show that the fibers rotate periodically in the zone where the shearing motion is dominant,and the fibers orientate along the single axis in the stretched zone. Meanwhile,the fiber orientation is more complex in the zone where the entrance of contraction and the upstream corner area have complicated flow,and the fiber orientation rotates irregularly due to the flow by the rotation.