Study And Experiment On Hydraulic Characteristics Of Parshall Flume

Water-gauging in canals is a basic foundation of the water management and a critical technique. It is of great significance for water saving and water utilization in irrigation districts efficiently and sustainable. For the purpose of using the water resources more effectively, people continuously explore a more accurate measure for water-gauging and scientific method for the manage of resources. The measuring flume is one of the water-gauging facilities, and Parshall flume is one of the most popular measuring flumes. Since the flume was developed, its use has expanded to industrial and municipal areas and has become one of the most widely used instruments for water measurement in the world(Genovez et al. 1993:1081). Lots of person carried on the subsequent research on the Parshall flume. This paper used the method of combination the theoretical research and model experiment, researched the hydraulic characteristics of Parshall flume, and summarized as follows:1,The paper summarized the research progress of Parshall flume, described the principal of Parshall flume and attentions on the installation and operation of Parshall flume. After analyzed data that obtained from the experiment, we achieved the discharge formula. The formulas are concise and practical, and have a good accuracy both under the free flow and submerged flow.2,The paper researched on the height of swell, the height of swell well increase with the discharge. There was a significant index relation between the upper water depth and the height of swell in the condition of free flow.3,The paper analyzed the principal of the head loss of the Parshall flume, we considered the head loss of the Parshall flume as local head loss. There was a linear relationship between the upper water depth and the head loss in the condition of free flow. The head loss in the condition of free flow is greater than it in the condition of submerged flow.4,The paper researched on the distribution of Froude number on the control section along the canal, then drawing out the curve of section specific energy. We also defined the section of critical water-depth through the trial calculation, it was located nearby the section which is 5cm in the front of the throat inlet. 5,This experiment measured the velocity along the longitudinal,lateral and vertical at the surface,middle and bottom of the water flow. Then we analyzed the distribution condition of the velocity along the canal.6,The paper researched on how dose the Parshall flume work in the condition of lots of sand. The result indicated that sand well not stay in the Parshall flume under the condition of free flow, this well assure the measuring accuracy of the Parshall flume in the canals with a lot of sand.