PIV Experimental Study on Flow Velocity Structure in Open Channel with Non-uniform Granular Rough Bed
The non-uniform particle roughness on the bed surface directly affects the velocity structure of open chan-nel flow.Based on the PIV flume test,the flow velocity structure in open channel with non-uniform granular rough bed is investigated.The distribution rules of the time-averaged flow velocity along the flow direction and along the vertical line are discussed,and the quadrant distribution characteristics of the pulsating flow velocity are analyzed.The results show that the large-scale non-uniform scattering roughness arranged in plum blossom shape significantly affects the flow struc-ture below the top of the particles,and the time-averaged flow structure is similar around the large and small particles,and the size of the particles significantly affects the shape scale of the flow separation zone and the location of the bounda-ry point of the inner and outer layers of the fluid.Quadrant analysis reveals that the large particles in the outer layer of the fluid decrease the probability of the Q2 and Q4 events in the area above them;The Q1 and Q3 events of the inner fluid dominate,and strong turbulence events are more likely to occur upstream and near large particles compared to down-stream and near small particles.
NETL
NSTL
万方数据
