堆积体对上游附近河道三维流速分布影响的试验研究

发布时间：2018-03-21 03:39

本文选题：堆积体　切入点：三维流速　出处：《长江科学院院报》2017年08期 　论文类型：期刊论文

【摘要】：堆积体的存在易对河道的水流流速产生影响。通过水槽试验,采用ADV观测堆积体附近的三维流速。通过控制流量大小,研究堆积体作用下河道三维流速沿堆积体上游临近横断面的分布规律。试验结果表明:(1)流量相同时,流速受堆积体形态影响。离河床越近,三维流速沿横断面的分布曲线:顺水流方向流速u的趋势线越陡,指向右岸一侧流速v和垂直河床向下流速w的峰值越向堆积体在横断面的投影线靠近。v由天然情况下趋于0的直线变成离河床越近,流速峰值越大,两岸流速越小的下抛物线。w在河床附近,曲线呈"勺子"形态,远离河床,曲线失去"勺子"形态。(2)随着流量增加,同一流层上,u流速增大,流速沿横向的分布越不均匀,曲线越陡。u流速方向和v流速方向的夹角θ,在离左岸(堆积体一侧)大约1/2堆积体半径时取得最小值。离左岸越远θ值越大,直至离左岸45 cm后θ才恢复天然值90°。研究成果可为河流防护和治理工作提供技术支撑。
[Abstract]:The existence of accumulation body is easy to influence the flow velocity of river channel. Through the flume test, ADV is used to observe the three dimensional velocity near the accumulation body. The distribution of 3-D velocity along the cross section near the upper reaches of the accumulation body under the action of the accumulation body is studied. The experimental results show that the velocity of the river is affected by the shape of the accumulation body when the flow rate is the same. The closer the channel is to the river bed, the closer it is to the river bed. The distribution curve of three dimensional velocity along the cross section: the steeper the trend line of flow velocity u in the direction of water flow, The peak value of velocity v pointing to the right bank and the downward velocity w of vertical riverbed moves closer to the projection line of cross section. V changes from the line that tends to 0 in natural condition to the closer to the riverbed, and the more the peak velocity is, the greater the peak velocity is. The lower parabola (w) with a smaller current velocity on both sides is in the shape of a "spoon" near the riverbed, and far away from the river bed, the curve loses the "spoon" shape. (2) with the increase of the flow rate, the velocity of flow on the same top layer increases, and the distribution of the velocity along the transverse direction is more uneven. The steeper the curve, the steeper the angle 胃 between the direction of flow velocity and the direction of v velocity, the minimum value is obtained when the radius of the deposit body is about 1/2 from the left bank (the side of the accumulation body). The farther away from the left bank, the greater the 胃 value. The natural value of 胃 is not restored to 90 掳until 45 cm from the left bank. The research results can provide technical support for river protection and control.
【作者单位】：西华大学能源与动力工程学院;西安科技大学通信与信息工程学院;
【基金】：国家自然科学基金项目(51409224) 研究生创新基金项目(ycjj2016094)
【分类号】：TV147

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