This paper presents an experimental study of angled fish-friendly bar racks with horizontal bars, using a physical model in an open channel. Head losses are investigated for two bar shapes, three ratios between bar spacing and bar thickness and four angles of orientation of the racks. The Froude and bar-Reynolds numbers were respectively 0.275 and 3600. The head loss coefficients decrease as the blockage ratio and the angle of orientation of the rack decrease. They are well predicted by a formula produced previously for an inclined rack, with some adaptations. Velocity fields are characterized upstream and downstream of the racks, showing no effect of the angle of orientation and no heterogeneity over channel width. Consequently, the normal and tangential components of the velocity along the rack are in agreement with the theoretical values given by angular decomposition. These results serve to assess the compliance with biological criteria to avoid impingement risks and guide fish towards a bypass.

本文介绍了使用明渠中的物理模型对带水平杆的有角度的鱼友好型酒吧架的实验研究。研究了两种棒材形状、三种棒材间距和棒材厚度之间的比率以及机架的四个定向角度的压头损失。Froude 和 bar-Reynolds 数分别为 0.275 和 3600。水头损失系数随着阻塞率和齿条定向角的减小而减小。之前为倾斜机架生成的公式很好地预测了它们，并进行了一些调整。速度场的特征在于机架的上游和下游，显示没有方向角度的影响，并且在通道宽度上没有异质性。所以，沿齿条的速度的法向分量和切向分量与角分解给出的理论值一致。这些结果有助于评估生物标准的遵守情况，以避免撞击风险并引导鱼类绕过。