基于图像测速的薄壁堰流表面流场测量方法

发布时间：2018-06-16 08:06

本文选题：薄壁堰流 + 表面流场　；参考：《水科学进展》2017年04期

【摘要】：针对薄壁堰流水面落差大、流速沿程变化剧烈的特点,提出一种测量堰流表面三维流场的有效方法。该方法基于双相机共面法重构水面形态(无需对相机进行复杂的内外参数标定)和大尺度粒子图像测速技术(LSPIV)测量二维流场,通过相机像平面与水面之间的空间映射关系,将像平面的二维流场数据逆投影至世界坐标系下已知坐标点的切平面上,解算出三维表面流场。该方法应用于薄壁堰流试验,有效重构了堰流三维表面形态及流场,其初步结果表明,堰流的流向速度在自由泄流长度范围内先增加后减小,转折点大致在自由泄流长度中间位置;在该位置之后,垂向流速占主导;同时该方法可行,计算结果合理。
[Abstract]:In view of the characteristics that the water surface drop of thin-walled Weir is large and the velocity along the flow path is changing sharply, an effective method for measuring 3D flow field on Weir surface is proposed. This method is based on the dual camera coplanar method to reconstruct the water surface shape (without complicated internal and external parameters calibration) and the large scale particle image velocimetry technique (LSPIV) to measure the two-dimensional flow field. The spatial mapping relationship between the camera image plane and the water surface is obtained. The two-dimensional flow field data of the image plane are inversely projected onto the tangent plane of known coordinate points in the world coordinate system, and the three-dimensional surface flow field is solved. The method is applied to the thin-wall Weir flow test, and the 3D surface shape and flow field of Weir flow are reconstructed effectively. The preliminary results show that the flow velocity of Weir flow increases first and then decreases in the range of free discharge length. The turning point is approximately in the middle of the free discharge length, after which the vertical velocity dominates. Meanwhile, the method is feasible and the calculation results are reasonable.
【作者单位】：清华大学水沙科学与水利水电工程国家重点实验室;
【基金】：国家自然科学基金资助项目(51279081)~~
【分类号】：TV132.2

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