坡面薄层水流流速测量的比较研究

在室内模拟水槽中分别用质心运动学原理、电解质脉冲法和流量法3种方法测量不同坡度、不同泥沙含量条件下的薄层水流流速。比较以上3种测量结果发现在下垫面无渗透时，即加入的盐液没有损失时，电解质脉冲法测量坡面薄层水流流速与质心运动速度及流量法测量结果基本是一致的。在泥沙含量较大时，电解质脉冲法测量结果的误差较大，流量对测量结果影响不显著；随着测量距离的延长，测量误差变小，这可能是随着测量距离的增加，加入电解质的时间与测量时间之比减小，从而使假设加入的电解质为电解质脉冲更加合理。总的来说，电解质脉冲法在实验条件下测量坡面薄层水流流速是可行的。

Comparative analysis of measurement of velocity of slope laminar flow

The velocity of sheet flow in simulating trough, which is at different slopes and discharges and sediment concentration, is measured with three methods, e.i., centroid-velocity calculating method, electrolyte-pulse method and flow-rate method. Comparing results measured by these three methods showed that velocity of flow measured by electrolyte pulse method agree with those of other two methods while no permeating in the bottom or no losing of salt solute in the experimental process. When the sediment concentration is too much, the error of velocity measured by electrolyte pulse method argument, but the discharge of flow affect the measuring results little. Prolonging the measuring distance can make the error of velocity measured by electrolyte pulse method decrease, which supposing the inputting electrolyte as a pulse become more in reason when the ratio between inputting time and measure interval decrease along the measuring distance increases. In a word, the electrolyte pulse method is feasible for measuring the velocity of sheet flow in the experimental condition.