Discussion on Flow Regime through Airfoil-shaped Measuring Flume

The aim of this research is to provide theoretical supports for deeply understanding flow regime of flow through airfoil-shaped measuring flume,which is classified into throatless type measuring flume,and to guide flume design and its application in irrigation districts.Based on experimental observations,energy and critical flow equations are introduced to deduce the location of critical flow in ideal condition,method of section specific energy is adopted to analyze relationship between energy and flow regimes.Flow regime of flow through flume is discussed and generalized qualitatively.The result shows that critical flow occurs in transverse cross section where lateral contraction gets minimal extremum(throat section) for airfoil-shaped measuring flume with horizontal bottom.Through analysis,it is got that three kinds of flow regimes(sub-,super-,critical flow) under five different conditions are in accordance with experimental observations.More good water measuring performances will be obtained if flow can be controlled by supercritical flow.