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| A novel free-surface vortex identification method |
| JIANG Jun,TANG Ren-zhong,LI Pei-yu |
| Department of Mechanical Engineering, Zhejiang University, Hangzhou 310027, China |
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Abstract In order to solve the existing problems within identification of free-surface vortex, such as low accuracy, large computation and poor availability, a novel free-surface vortex identification method was proposed. This method established a real-time free-surface vortex identification system which based on image recognition technology, and realized image acquisition, sampling, processing and vortex identification. To address the difficulties of vortex identification in this system, a proper vortex identification and location within two-dimensional image approach was put forward. This approach using the local symmetry of the vortex image, analyzed the direction of streamlines around vortex field in image, calculated the corresponding angle value by improved winding angle method, and ultimately achieved to recognize free-surface vortex and find vortex core. Experiments show that this method has not only a high recognition speed and accuracy, but also well-behaved stability and effectiveness.
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Published: 01 May 2012
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自由表面旋涡的识别方法
针对目前自由表面旋涡识别所存在的精确性低、计算量大、实用性差的问题,提出一种新的自由表面旋涡识别方法.该方法建立基于图像识别的自由表面旋涡识别系统,实现图像获取、采集、处理及旋涡识别的功能.为了解决系统中旋涡识别的难点问题,提出一种二维图像中旋涡的识别及定位方法.该方法利用旋涡图像的局部对称性,通过分析图像中旋涡周围流线的方向场,使用改进后的缠绕角度法计算相应的缠绕角度值,最终实现自由表面旋涡的识别及涡核中心的定位.实验表明,该方法识别速度快且具有较高的准确,稳定及有效性.
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