中文摘要：

通过自制模型对侧向水平孔口的立轴旋涡进行基础试验研究。使用有色颜料追踪旋涡表面的质点运动，观测到其轨迹线为多圈螺旋流，并根据这一特性采用摄像法和图形处理技术对时均速度进行测量，与理论结果对比证明这种简单经济的方法是可行的。通过改变试验装置分析来流方向对旋涡的影响，表明进口轴线与来流方向之间的夹角过大是形成立轴旋涡的诱因之一。根据试验结果得出不同来流方向的临界淹没水深计算公式，并对公式进行推广，可作为设计时的参考依据。

英文摘要：

The model investigations of the vertical vortex at a horizontal intake are performed by a self-made model. The particle movement at the surface of the vertical vortex is traced by a color pigment, which shows the moving trace is a mtdti-circle helical flow. According to the characteristics, the average tangential and axial velocities are obtained by the photography method and the image processing technique. By comparison with the theoretical results, the simple and economic means is proved to be feasible. The influence on the vertical vortex formation of different approaching directions is also analyzed, and the result shows the oversize angle between the intake axis and the approaching direction is a factor of the vertical vortex generation. The formulas of the critical depth of submergence of different approaching directions are obtained by the measured data, and the formula is extended for the reference of the design.