Swirling Flow of a Viscoelastic Fluid With Free Surface—Part I: Experimental Analysis of Vortex Motion by PIV
Swirling Flow of a Viscoelastic Fluid With Free Surface—Part I: Experimental Analysis of Vortex Motion by PIV
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DOI：
10.1115/1.2136928
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发表时间：
2006
影响因子：
2
通讯作者：
Jinjia Wei;Feng-chen Li;Bo Yu;Y. Kawaguchi
中科院分区：
文献类型：
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作者：
Jinjia Wei;Feng-chen Li;Bo Yu;Y. Kawaguchi
用双脉冲PIV(粒子图像测速)系统对水和CTAC(十六烷基三甲基氯化铵)表面活性剂溶液(50-1000ppm)在底部有旋转圆盘的开口圆柱形容器内的旋转流动进行了实验研究。当雷诺数为4.3×104时，水在子午面内的流动形态与低雷诺数时有很大不同，旋涡破裂产生的反向旋涡将惯性驱动的旋涡推向自由面与圆柱壁之间的拐角处。对于1000ppm的表面活性剂溶液流动，惯性驱动涡位于底部和圆柱壁之间的拐角处，而弹性驱动的逆涡则主导了大部分流场。流体的旋转引起自由表面的变形，中心有一个倾角。在水的情况下，倾角最大，并且随着表面活性剂浓度的增加而减小。倾角的大小与确定减阻开始时的溶液粘弹性有关。
The swirling flows of water and CTAC (cetyltrimethyl ammonium chloride) surfactant solutions (50-1000 ppm) in an open cylindrical container with a rotating disc at the bottom were experimentally investigated by use of a double-pulsed PIV (particle image velocimetry) system. The flow pattern in the meridional plane for water at the present high Reynolds number of 4.3 X 10 4 differed greatly from that at low Reynolds numbers, and an inertia-driven vortex was pushed to the corner between the free surface and the cylindrical wall by a counter-rotating vortex caused by vortex breakdown. For the 1000 ppm surfactant solution flow, the inertia-driven vortex located at the corner between the bottom and the cylindrical wall whereas an elasticity-driven reverse vortex governed the majority of the flow field. The rotation of the fluid caused a deformation of the free surface with a dip at the center. The dip was largest for the water case and decreased with increasing surfactant concentration. The value of the dip was related to determining the solution viscoelasticity for the onset of drag reduction.