The Experimental And Applied Research Of Standardized Airfoil-shaped Measuring Flume In Channels At Final Stage

With development of market economy and stress of water resources measuring as a method of optimal allocation of water resources and irrigation district management has been playing a significant role day by day. Thus, to research and develop a new water measuring facility which is suited to current development and meet to specifical demand in irrigation district is the springboard of the research,especially for a large number of irrigation channels at final stage.The Airfoil-shaped measuring flume, which is characterized by its simple structure,smooth flow and low head loss, can be studied for popularization and application at irrigation district. According to the synthetic analysis of indoor and outdoor experiments, with the combination of standardization theory and experimental study, this paper studies airfoil-shaped measuring flume on irrigation channels at final stage by standardized method and puts research results in practice. The main research results and conclusions are as follows:1,Through the analysis of standardization theory, according to characteristics of channels at final stage, structure form and principle of measuring runoff of airfoil-shaped measuring flume, the paper puts forward the opinion on standardization, burdening mode and standard form by index of contraction ratio which can form specification.2,Experiment chooses standard models of airfoil-shaped measuring flume basing on different contraction ratio. The results show that measuring flume has high-flow measurement precision. The formula is brief and concise which established by dimensional analysis. With comparison of calculated flow rate and actual measured flow, error is small, and the accuracy comforts code requirement. Through further analysising, it was obtained that the critical submergence in airfoil-shaped measuring flume is higher and in the range of experiment contraction ratio which is 0.79-0.90.The head loss of flume is less.3,Study on the experiment of the airfoil-shaped measuring flume in Inner Mongolia Hetao irrigation district and the south bank of Yellow river irrigation district in Oerhtossu, shows that the accuracy of flow measurement can meet the requirement which require the error less than 5%. Experimental study suggested that that airfoil-shaped measuring flume is a new type water measuring device, which suited to irrigation channels at final stage with simple structure and good results. The paper summarizes the steps of design and construction with formwork,which designs the measuring flume as unified standard sand meets the requirement of accuracy.4,Airfoil-shaped measuring flume combined with ultrasonic sensor and secondary instrument not only can accurately measure but also transfer data by in real time by wireless transmission system. This mode provides reliable evidence for scientific operation and optimal water allocation which improves modern management level of irrigation district.