【作者】 刘鸿涛；

【导师】 吕宏兴；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2008， 硕士

【摘要】 机翼形量水槽是直接在原有或新建棱柱体渠道上,以渠道轴线为对称轴修建机翼柱形,促使水流在该处形成临界水流状态进行流量测量的量水设备,无需改变渠道断面结构,适合在对称的矩形、U形等断面渠道上安装使用。本文介绍了机翼形量水槽的测流原理和结构形式,通过量纲分析得到了具有量纲和谐形式的机翼形量水槽流量计算公式。分别在甘肃省引大入秦工程总干渠矩形渠道和内蒙古河套灌区沙壕渠试验站一斗渠U形渠道上修筑了机翼形量水槽,利用灌区冬灌的机会,进行机翼形量水槽的应用研究。在机翼形量水槽运行过程中,用超声波流速仪、电磁流速仪、旋桨流速仪、超声波流量计、压力传感器、超声波传感器、垂球、水准仪等采集应用实时数据,对机翼形量水槽应用测流性能和实际运行效果进行研究。同时,将修筑在引大入秦总干渠上的机翼形量水槽按1:7.5的比尺缩小,在西北农林科技大学水工试验大厅进行模型试验,对应用研究进行补充。结合应用研究实测数据与模型试验数据,发现机翼形量水槽实际应用时量水精度符合量水规范要求并且满足实际应用条件。进一步分析得到了机翼形量水槽应用时淹没度、上游佛汝德数、下游水跃形式、水头损失、壅水高度等性能参数。本文总结了应用中机翼形量水槽与水位自动监测系统配合使用情况,认为机翼形量水槽实时监控水量连续性好、灵敏度高,是一种适用于灌区现代化管理的新型量水槽。对机翼形量水槽在临界淹没情形下的试验数据进行分析,发现在流量一定的情况下,机翼形量水槽的收缩比与矩形渠道底坡存在线性关系,收缩比随底坡的增大而增大。按线性关系计算得到机翼形量水槽收缩比与矩形渠道底坡的关系表,归纳出矩形渠道机翼形量水槽初步设计方法步骤,并罗列了应用机翼形量水槽的矩形渠段条件和水流条件,以及机翼形量水槽安装和水位测量的要求。更多还原

【Abstract】 Airfoil-shaped measuring flume is a kind of equipment which can prompt a critical water-flow to measure of the flow of water. It can be directly built in the original or new prism channels, without changing section structure of channels, and it is particularly well adapted for use in symmetrical rectangular, U-shaped cross section. Airfoil-shaped measuring flume and the channel have the same symmetry axis.This article introduced the principles and structure of airfoil-shaped measuring flume, and obtained dimension harmonious flow calculating formula through the dimensional analysis. Applied research has been carried on the ailfoil-shaped measuring flumes which have been constructed Separately in the rectangle channel of Yinda project total main channel in the Gansu Province and U channel of Shahao canal in Inner Mongolian He Tao irrigation area.During the measuring flume running process, ultrasonic current meter, electromagnetism current meter, oar current meter, ultrasonic flowmeter, pressure transmitter, ultrasonic sensor, plumb, level gauge, and so on, was used to collect Real-time data, in order to research on the water measuring performance and the actual running effect.At the same time, airfoil-shaped flume was constructed in the hydraulic experiment hall in Northwest A&F University based on the Yinda project total main channel’s water measuring flume according to 1:7.5 ratio to carriy on the model experiment, which is the complementarity to the applied research.According to the applied research measured data and the model experiment data, we foune that the water measuring precision of airfoil-shaped measuring flume meets the requirement of water measuring standard, and satisfies the practical application condition.Through further analyzes, we obtained some performance parameters in the airfoil-shaped measuring flume application, such as submerged extent, Fr of upstream, form of hydraulic jump downstream, head loss, backwater hight, and so on.Summarizing the mating reaction of the airfoil-shaped measuring flume and the water level automatic monitoring system in the application, the thesis considers that with characteristics of good continuity during real-time monitoring and high sensitivity, airfoil-shaped measuring flume is a new water measuring flume which is surtable for modern management in irrigated areas. Through analyzing the test data in the critical circumstances, we found that there is a linear relation between contraction ratio of the airfoil-shaped measuring flume and the channel bottom slope under the constant flow circumstance, and the contraction ratio creases along with the slope increases.The contraction ratio and slope relation table of airfoil-shaped measuring flume was obtained, according to the linear relation computation. The paper induces preliminary design method step of airfoil-shaped measuring flume in the rectangular channel, and has displayed rectangular ditch section condition and the fluent condition in application to airfoil-shaped measuring flume, as well as the requirements of airfoil-shaped measuring flume installment and water level survey.更多还原