Author Contributions
Conceptualization, F.L., L.C., D.C., and L.D.; methodology, F.L. and L.D.; software, F.L.; validation, F.L. and L.D.; formal analysis, F.L.; investigation, F.L.; resources, F.L.; data curation, F.L.; writing—original draft preparation, F.L..; writing—review and editing, F.L., L.C., D.C. and L.D.; visualization, F.L.; supervision, L.C. and L.D.; project administration, L.C., D.C. and L.D.; funding acquisition, L.C. and L.D. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Open flow channel at the Pprime Institute.
Figure 1.
Open flow channel at the Pprime Institute.
Figure 2.
Trash rack components (bars, spacers, transversal supports, and longitudinal supports) and tested bar shapes.
Figure 2.
Trash rack components (bars, spacers, transversal supports, and longitudinal supports) and tested bar shapes.
Figure 3.
Bar shapes dimensions: thickness (b) and depth (p).
Figure 3.
Bar shapes dimensions: thickness (b) and depth (p).
Figure 4.
Transversal support dimensions: U-shaped on the left and profiled shapes on the right, placed in front of the spacers.
Figure 4.
Transversal support dimensions: U-shaped on the left and profiled shapes on the right, placed in front of the spacers.
Figure 5.
Location of the measurement points in the channel.
Figure 5.
Location of the measurement points in the channel.
Figure 6.
Vertical projection of the support to estimate the frontal blockage.
Figure 6.
Vertical projection of the support to estimate the frontal blockage.
Figure 7.
Comparison of measured head loss coefficients for the four bar shapes ((a) for Droplet, (b) for Plétina, (c) for Tadpole 8, (d) for Tadpole 10) and the two bar spacings for each one, as a function of the angle of inclination .
Figure 7.
Comparison of measured head loss coefficients for the four bar shapes ((a) for Droplet, (b) for Plétina, (c) for Tadpole 8, (d) for Tadpole 10) and the two bar spacings for each one, as a function of the angle of inclination .
Figure 8.
Linear regression of the for the four bar shapes ((a) for Droplet, (b) for Plétina, (c) for Tadpole 8, (d) for Tadpole 10) as a function of the .
Figure 8.
Linear regression of the for the four bar shapes ((a) for Droplet, (b) for Plétina, (c) for Tadpole 8, (d) for Tadpole 10) as a function of the .
Figure 9.
Comparison of measured head loss coefficients without, with one or two U-shaped supports (US) for (a) PR for a bar spacing of 10, (b) PR for a bar spacing of 15, (c) PH for a bar spacing of 10, and (d) PH for a bar spacing of 15, as a function of the angle of inclination .
Figure 9.
Comparison of measured head loss coefficients without, with one or two U-shaped supports (US) for (a) PR for a bar spacing of 10, (b) PR for a bar spacing of 15, (c) PH for a bar spacing of 10, and (d) PH for a bar spacing of 15, as a function of the angle of inclination .
Figure 10.
Comparison of measured head loss coefficients with one and without the profiled shape (PS) support for (a) PR for a bar spacing of 10, (b) PR for a bar spacing of 15, (c) PH for a bar spacing of 10, and (d) PH for a bar spacing of 15, as a function of the angle of inclination .
Figure 10.
Comparison of measured head loss coefficients with one and without the profiled shape (PS) support for (a) PR for a bar spacing of 10, (b) PR for a bar spacing of 15, (c) PH for a bar spacing of 10, and (d) PH for a bar spacing of 15, as a function of the angle of inclination .
Figure 11.
Linear regression between the measured and modeled head loss coefficients for (a) the U-shaped support and (b) the profiled shape support.
Figure 11.
Linear regression between the measured and modeled head loss coefficients for (a) the U-shaped support and (b) the profiled shape support.
Table 1.
Hydraulic (Q, , , Re, Fr) and trash rack (e, ) parameters.
Table 1.
Hydraulic (Q, , , Re, Fr) and trash rack (e, ) parameters.
Parameters | Values | Units |
---|
Bar spacing e | 17.2/18.2/20.2/27.8/28.8/30.8 | (mm) |
Angle of inclination | 15/25/35/45/60/90 | () |
Discharge Q | 0.29/0.48/0.5 | (ms) |
Upstream water depth | 0.42/0.67/0.7 | (m) |
Approach velocity | 0.72 | (ms) |
Reynolds number | 720,000 | (-) |
Bar-Reynolds number | 3600/5760/7200/8640 | (-) |
Froude number | 0.27/0.28/0.35 | (-) |
Table 2.
Bar parameters (b,p) for the different bar shapes (Droplet, Plétina, Tadpole 8, Tadpole 10, hydrodynamic, rectangular).
Table 2.
Bar parameters (b,p) for the different bar shapes (Droplet, Plétina, Tadpole 8, Tadpole 10, hydrodynamic, rectangular).
Bar Shape | Maximum Thickness b (mm) | Depth p (mm) | e/b (-) |
---|
Droplet | 10 | 80 | 2/3.1 |
Plétina | 12 | 60 | 1.4/2.3 |
Tadpole 8 | 8 | 60 | 2.3/3.6 |
Tadpole 10 | 10 | 80 | 1.8/2.9 |
Hydrodynamic | 5 | 40 | 1/2/3/4 |
Rectangular | 5 | 40 | 1/2/3/4 |
Table 3.
Bar shape coefficients of the tested profiles.
Table 3.
Bar shape coefficients of the tested profiles.
Bar Shape | Droplet | Plétina | Tadpole 8 | Tadpole 10 | Hydrodynamic | Rectangular |
---|
Bar coefficient | 2.47 | 1.75 | 1.27 | 1.79 | 2.10 | 3.85 |
ratio (%) | 64.2 | 45.5 | 33 | 46.5 | 54.5 | 100 |