横跨航槽水流结构变化规律试验研究

Experimental study of flow structure variation across dredged channel

为了研究横跨航槽水流结构的变化,分析流速垂向分布和沿程分布规律,进行了物理模型水槽试验,根据水槽试验结果对横跨航槽水流垂线平均流速的沿程折减变化做了定量的分析,并得出槽滩水深比和来水流速两个因素对跨越航槽水流结构变化的影响。试验结果表明,上边坡垂线平均流速相比于下边坡要稍小些;在边坡为1∶3,槽滩水深比为1.71~1.84,来水流速为0.034~0.202 m/s情况下,横跨航槽水流在上边坡中点附近到航槽内距上边坡坡脚一定距离这一区域,底部水流反向运动形成"回流"区域,来水流速越小,槽滩水深比越大,形成"回流"区域的范围就越大,流速发生的折减也就越大。

In order to study the structural changes with the flow across the dredged channel and analyze the regularity of vertical distribution and longitudinal distribution, we performed the physical model test. Based on the results of the physical model test, we made the quantitative analysis of depth-averaged velocity discount variation across the trench, and obtained the effects of trough-beach depth ratio and the flow velocity on the flow structure. The results showed that, the depth-averaged velocity of the upper slope is slightly smaller than that of the lower slope. When the slope is 1：3, trough-beach depth ratio is 1.71 to 1.84, and the flow velocity is 0.034 m/s to 0.202 m/s, the reverse flow at the bottom formed the ＂reture＂ area in this area, where the midpoint of the upper slope to the dredged channel a certain distance from the slope toe. The smaller the flow velocity and the greater trough-beach depth ratio, the ＂reture＂ area is greater, and the depth-averaged velocity discount is greater as well.