Flow-stream-bed interaction has received substantial interest in the field of fluvial hydraulics since few decades and the present study aims to explore the influenece of weak bed-load transport on near-bed flow characteristics under dynamic equilibrium flow conditions. The experimental conditions were tackled in two folds: (1) flow over immobile bed without bed-load transport and (2) weak bed-load transport over the immobile bed. A layer of well-sorted sand grains was glued on the flume bottom to develop an immobile sand bed surface. Uniformly graded sediments were injected into the flows for sediment motion in the form of weak bed-load transport. Nineteen dynamic equilibrium flow conditions were established and an acoustic Doppler velocimeter was used to measure the instanteneous velocity. The weak bed-load transport induced massive damping in Reynolds shear stress distributions and enhanced streamwise velocity gradients. Most significantly, turbulent kinetic energy flux components showed positive streamwise and negative vertical fluxes in the near-bed flow region corroborating an accelerating effect on the inertia of flowing fluid. The results associated to turbulent parts of kinetic energy components are further illustrated in the light of turbulent kinetic energy budget concept to elucidate the influence of weak bed-load transport on mean flow characteristics.

几十年来，流-床-床层相互作用在河流水力学领域引起了极大的兴趣，本研究旨在探讨弱床-床输运对动态平衡流条件下近床层流特征的影响。通过两个方面解决了实验条件：（1）在没有床载运输的情况下流过固定床；（2）在固定床之上的弱床载运输。将一层分类良好的沙粒粘在水槽底部，以形成固定的沙床表面。将均匀分级的沉积物以弱床荷运输的形式注入流中，以使沉积物运动。建立了19个动态平衡流动条件，并使用声学多普勒测速仪测量瞬时速度。较弱的床荷输运引起了雷诺剪切应力分布中的大量阻尼，并增加了沿流速度梯度。最重要的是，湍流动能通量分量在近床流区域中显示出正向流动和负向垂直通量，从而证实了对流动流体惯性的加速作用。根据湍动能预算概念进一步阐明了与动能分量的湍流部分相关的结果，以阐明弱床层输运对平均流特征的影响。湍流动能通量分量在近床流动区显示出正向流动和负向垂直通量，从而证实了对流动流体惯性的加速作用。根据湍动能预算概念进一步阐明了与动能分量的湍流部分相关的结果，以阐明弱床层输运对平均流特征的影响。湍流动能通量分量在近床流动区显示出正向流动和负向垂直通量，从而证实了对流动流体惯性的加速作用。根据湍动能预算概念进一步阐明了与动能分量的湍流部分相关的结果，以阐明弱床层输运对平均流特征的影响。