恒定流中泥沙运动速度实验

泥沙颗粒运动速度与水流运动速度是不一致的,进而会对水流输沙和河床演变产生影响。通过采用粒子追踪测速方法(Particle Tracking Velocimetry-PTV)和粒子图像测速技术(Particle Image Velocimetry-PIV)测量了水槽中2种粒径的泥沙颗粒运动速度及相应的水流运动速度。实验结果表明,泥沙颗粒运动速度沿垂线分布与水流速度不一致,在对数区,泥沙颗粒的运动速度略小于水流的速度,泥沙运动滞后于水流运动;在近壁区,泥沙颗粒的运动速度大于水流速度,且在本实验的粒径范围内,随着泥沙颗粒粒径增大,泥沙颗粒的运动速度也随之增大。

Experiments on Velocity of Sediment Movement in Steady Flow

The velocity of sediment particles movement is not the same as the flow velocity,which can affect the sediment-carrying of flow and river channel process.In this study,the Particle Tracking Velocimetry(PTV) and Particle Image Velocimetry(PIV) methods are used to measure the velocities of two sediment particles and the corresponding flow velocities in a water tank.The results show that the vertical distributions of the sediment movement velocity and flow velocity are different.In the logarithmic region,the velocities of sediment particles movement are slightly lower than the flow velocities;whereas in the near-wall region,the velocities of sediment particles movement are higher than the flow velocities.For the sediment particles investigated in this study,the velocity of sediment particles movement increases with the increasing of the particle diameter.