【摘要】 针对现有掺气水流速度实测资料较少,且测量结果存在较大差异,采用针式掺气浓度仪对自掺气水流的流速进行了实验研究,结果表明:明渠自掺气水流的速度存在一个自底面向水面方向不断增大,然后再逐渐减小的过程;依据测量所得的掺气浓度与流速资料,采用分段求和的方法得到的断面统计流量与实际流量的误差很小,表明测量结果是可靠的。将试验结果与前人的研究成果进行分析比较发现:掺气水流的速度分布与水流是属于部分掺气、完全掺气还是强烈掺气等有关。前人在研究掺气水流的速度分布规律时,之所以得出了不同的掺气水流速度分布规律,是由于掺气强度不同所致。更多还原

【Abstract】 A set of needle-type air concentration and velocity instrument was used to investigate the velocity distribution of self-aerated flows. The results show that the velocity of self-aerated flows increases along the vertical line from the bottom and then decreases toward the water surface. On the basis of experimental data of air concentration and velocity, the discharge of each transverse section is got by means of stereometry. The calculated and experimental discharge are compared and are in good agreement, which proves that the measured velocity distribution is reliable. The comparison between the experimental data and the former researcher’s data shows that the velocity profile of self-aerated flows depends on the style of self-aerated flows, i.e. partial aeration, full aeration or strong aeration. The difference among former researcher’s results is due to the aeration strength.更多还原