Numerical processing of flow-visualization pictures – measurement of two-dimensional vortex flow
Numerical processing of flow-visualization pictures – measurement of two-dimensional vortex flow
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流动可视化图像的数值处理——二维涡流的测量
DOI：
10.1017/s0022112083000774
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发表时间：
1983
影响因子：
3.7
通讯作者：
K. Ohmi
中科院分区：
文献类型：
--
作者：
K. Imaichi;K. Ohmi
通过流动显示和图像处理技术，开发了一种新的系统，用于实验估计流体流动的一些主要物理量。用该系统计算了两个二维流的流函数、涡量和压力分布，计算结果具有较高的精度。这两个例子分别是脉冲加速到恒速的圆柱体后的非定常双涡流动和匀速运动的圆柱体后的Kármán涡。首先对图像处理技术和数值计算过程进行了详细的说明，然后对这两种流动的计算结果进行了讨论。比较表明，非定常双涡实验的某些结果与已发表的实验研究和理论计算结果吻合较好。对该系统每一阶段引入的误差进行了较为详细的估计。
A new system has been developed for estimating experimentally some of the principal physical variables of fluid flows, through flow-visualization and image-processing techniques. Distributions of stream function, vorticity and pressure are calculated by this system with reasonable accuracy for two examples of two-dimensional flow: namely unsteady twin-vortex flow behind a circular cylinder accelerated impulsively to constant speed, and Kármán vortices behind a circular cylinder moving at constant speed. A detailed explanation of the image-processing technique and the numerical calculation process is given first, and then some consideration is given to calculated results in these two types of flow. Comparison shows that some results of the unsteady twin-vortex experiment coincide well with those of previously published experimental investigations and theoretical calculations. Errors introduced at each stage of this system are estimated in some detail.