U形渠道便携式板柱结合型量水槽水力性能研究

Hydraulic Performance of Plate-column Portable Flume in U-shaped Channel

摘要:

针对灌区小型渠道数目多、需测控的断面多、而宜采用的移动式量水设备仍不够完善的问题，借鉴移动式薄板量水槽和圆柱量水槽的优点，设计了一种便携式板柱结合型量水槽，在分析量水槽测流机理的基础上，开展原型试验和数值模拟研究，并应用量纲分析法建立测流公式。结果表明，量水槽具有较好的水位-流量关系，上游壅水高度在1.85～13.69cm之间，临界淹没度在0.70～0.91之间，槽前弗汝徳数均小于0.5；板柱结合型量水槽比现有的圆柱量水槽和带尾翼的圆头量水槽体型小，便携度高，流线分布稍差，上游壅水高度稍大，临界淹没度稍低，但能满足灌区测流要求；量水槽测流精度高，平均测流相对误差为2.07%。

Abstract:

Flow measurement facilities in channels are the basis for charging agricultural water according to water consumption. Because the number of small channels in irrigation districts is large, there are many sections to be measured. Therefore, mobile flow measurement facilities are recommended to measure the discharge. However, the existing mobile water measuring facilities are still not suitable enough. Combining the advantages of mobile thin plate flumes and cylindrical flumes, a plate-column portable flume was developed. Based on the analysis of the mechanism of flow measurement for the flume, prototype tests and numerical simulations of the plate-column portable flume were carried out. And the flow measurement formula was established by using the dimensional analysis method. The results showed a good relationship between water depth and flow rates in plate-column portable flumes. The upstream backwater height was between 13.69cm and 1.85cm, the critical submergence was between 0.91 and 0.70, and the Froude number Fr at the upstream of the plate-column portable flume was less than 0.5. The plate-column portable flume had a smaller shape than the existing circular flume and the flume with a round head and a empennage, and had a higher portability and a slightly worse streamline distribution;its upstream backwater height was slightly larger and its critical submergence was slightly lower, but that still can meet the requirements of the flow measurement in the irrigation area. The plate-column portable flume had a high accuracy that the average relative error of which was only 2.07%, and had the prospect of generalization and application.