An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks

Sylvain Raynal (1) , Dominique Courret (2, 3, 4) , Ludovic Chatellier (5) , Michel Larinier (2, 3, 4) , Laurent David (5)

1 PPrime [Poitiers] - Institut Pprime [UPR 3346]
2 IMFT - Institut de mécanique des fluides de Toulouse
3 ONEMA - Office national de l'eau et des milieux aquatiques
4 IRSTEA - Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture
5 HydEE - Hydrodynamique et écoulements environnementaux [Institut Pprime]

Experimental results are presented for trashracks placed in an open water channel with different bar shapes, spaces between bars and screen inclination angles. The numerous configurations provided results on head losses and on changes in velocity along the rack for a large range of situations, including fish-friendly trashracks. A new head-loss equation is proposed that takes into account the effect of the different tested parameters and demonstrates the need to separate the effect of the trashrack bars, which is directly related to the inclination of the trashrack, from the effect of the transversal elements such as spacer rows whose effect on the flow is not altered by rack inclination. Velocity measurements also adduce rules for efficient water intakes complying with fish-friendly criteria.

Mots clés: Downstream migration; Experimental hydraulics; Head loss; Inclined trashrack; Open channel

Domaines: Ecologie, Environnement; Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Sylvain Raynal, Dominique Courret, Ludovic Chatellier, Michel Larinier, Laurent David. An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 2013, vol. 51, pp. 56-66. ⟨10.1080/00221686.2012.753646⟩. ⟨hal-00967468⟩