明渠渠底糙率突变对紊流边界层影响的试验研究

利用激光测速仪,对壁面糙率突变时的明渠紊流进行了试验研究,测量了糙率突变不同水深情况下明渠紊流的纵向时均流速和脉动流速。通过实测资料分析水深和糙率改变后内边界层发展变化规律、粗糙度和水深对内边界层的厚度的影响以及糙率突变后从一种均匀流到形成新的充分发展的紊流所需要的纵向长度。

Experimental Research on the Influence of the Mutation of the Roughness of the Bottom Wall of Open Channel on the Turbulence Boundary Layer

This paper makes experimental study on the turbulence under roughness coefficient mutation on bottom wall of open channel,measures the mean velocity and fluctuating velocity of turbulence at different water depth by using LDV,and based on a lot of experimental results,analyzes the evolving rules and thickness of boundary layer at different water depth and with different roughness coefficient,and studies on the necessary longitudinal length when flow changes from homogeneous flow to new turbulence.