摘要
该文利用粒子图像测速方法(PIV)对光滑床面条件下水深为3~7mm的坡面流流场进行了详细测量,并将分析结果与普通明渠流进行了系统对比。尽管坡面流的水深已达到毫米量级,但仍可以将其流态区分为层流、过渡流和紊流。坡面流条件下的流速呈抛物线或对数分布,当处于过渡区时,流速分布仍符合对数律,但其积分常数随雷诺数的增大而减小。与普通明渠流相比,坡面流的紊流内区范围偏大,当雷诺数较低时,水流黏性的影响可扩大至整个水层。受极浅水深的影响,坡面流的紊动强度在垂向上偏小,而在纵向上则明显偏大。
Detailed measurements of the flow velocity of overland flow with a depth of 3~7 mm under smooth bed conditions are conducted using particle image velocimetry(PIV).The results are systematically compared with those of ordinary open channel flows.Although the flow depth of the overland flow has reached the millimeter scale,it is still possible to distinguish the flow patterns into laminar,transitional,and turbulent stages.The flow velocity follows a parabolic or logarithmic distribution.It generally agrees with the logarithmic law in the transition,but the integration constant decrease with increasing Reynolds number.Compared to ordinary open channel flows,the inner region of the turbulent boundary layer in an overland flow has a larger range.At low Reynolds numbers,the effect of flow viscosity can be extended to the entire flow layer.Due to the shallow flow depth of overland flow,the turbulent intensity is weakened in the vertical direction but strengthened in the longitudinal direction.
作者
季铭昱
程年生
李奇骏
Ji Mingyu;Cheng Niansheng;Li Qijun(Ocean College,Zhejiang University,Zhoushan 316021,China)
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2023年第4期655-661,共7页
Chinese Journal of Hydrodynamics
关键词
坡面流
流速分布
紊动特性
流态
Overland flow
Velocity distribution
Turbulence characteristics
Flow patterns
