Turbulent flow field comparison and related suitability for fish passage of a standard and a simplified low‐gradient vertical slot fishway

Quaranta, Emanuele; Katopodis, C; Revelli, Roberto; Comoglio, Claudio

doi:10.1002/rra.3193

Cited by 57 publications

(41 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, to assess the effects of hydrodynamics on the fish behavior, numerical modelling (the 3D CFD model FLOW-3D ® ) was used in this study to characterize influential hydrodynamic variables, such as velocity magnitude, TKE, and water depths, present in each configuration tested, in order to identify areas of high velocity and turbulence gradients that might have affected the fish movements. Over the last few years, 3D CFD models have proved to be a practical and robust tool to characterize hydrodynamics on several hydraulic structures, being widely used for the assessment of fish passages (e.g., studies on functioning over a wide range of discharges, prediction of suitable conditions for fish), optimization of designs, and evaluation of different retrofitting solutions [52][53][54][58][59][60][61][62][63][64]. However, given that uncertainty in CFD modelling for environmental fluid mechanics in complex flow fields, like the flow field in the vicinity of a macro-scale roughness (e.g., wake region), can arise from a very wide range of sources, care should be taken when performing a numerical model study [65].…”

Section: Discussionmentioning

confidence: 99%

Assessment of Retrofitted Ramped Weirs to Improve Passage of Potamodromous Fish

Amaral

Quaresma

Branco

et al. 2019

Water

View full text Add to dashboard Cite

The addition of substrates to small instream obstacles, like low-head ramped weirs, has been considered a useful management solution to retrofit those structures and enhance fish passage. Substrate dimensions and spatial arrangement, together with discharge, and consequently water depths, appear as important factors for the creation of hydrodynamic conditions that may facilitate the successful passage of fish, though related studies are scarce to support decision-making. This study assessed the influence of discharge (Q) and different retrofitting designs (RD) on the upstream passage performance of a potamodromous cyprinid, the Iberian barbel (Luciobarbus bocagei). Different substrates (small boulders, large boulders, cobbles) and spatial arrangements (aligned, offset) were tested. Numerical modelling was performed to characterize the hydrodynamics. Results indicate that Q and RD influenced the upstream negotiation of ramped weirs. Cobbles randomly distributed along the ramp (Nature design) was the most successful configuration, recording the highest number of upstream passages. Low velocities along the ramp, and low turbulence downstream, were registered in this configuration, indicating that the use of natural substrate may help to increase the permeability of ramped weirs to fish movements. The outcomes from this work can help engineers and biologists to design more appropriate passage structures for low-head instream obstacles.2 of 18 after assessment, could not be removed, have undergone rehabilitation works to include ramps in their designs (e.g., [11,12]). This design reconfiguration enables water to pass over the ramp, not generating a waterfall [5,10], a condition that may afford a more holistic negotiation by fish [5,13]. Nevertheless, fish swimming abilities, which are closely related to fish guilds and body size [14][15][16][17], and hydrodynamic conditions, such as water depth, discharge, and turbulence present over the ramp and in the vicinity of the structure [5,[18][19][20], are key factors that influence the permeability of such structures to fish movements.The addition of substrates to instream obstacles and fish transposition devices, commonly referred to as retrofitting, has been considered a useful management solution to enhance upstream fish passage [5,[21][22][23][24][25][26][27][28]. The placement of substrates in culverts to mimic natural stream conditions and facilitate fish passage has been successfully implemented since the early 1970s [29]. In low-head ramped weirs, natural substrates like pebbles, cobbles, or boulders, are frequently used as retrofitting solutions to increase the bed roughness, and consequently promote energy dissipation, creating localized zones of low-velocity and turbulence [23][24][25]30] that may be used by fish as resting areas during the upstream negotiation of ramps [20,27,[31][32][33]. These low velocities may be especially important to species of weaker swimming capabilities, such as potamodromous cyprinids [5,21,22]. Substrate dimensions and spatial arrang...

show abstract

Section: Discussionmentioning

confidence: 99%

Assessment of Retrofitted Ramped Weirs to Improve Passage of Potamodromous Fish

Amaral

Quaresma

Branco

et al. 2019

Water

View full text Add to dashboard Cite

show abstract

“…Therefore, in this study, a computational fluid dynamic (CFD) RANS model was used. The CFD model was based on the commercial software Ansys Fluent, and it has been validated against experimental data (head discharge and flow field) in Quaranta et al (). Three momentum equations (one equation for each Cartesian coordinate) and the continuity equation were solved.…”

Section: Methodsmentioning

confidence: 99%

“…The volume of fluid method was used to determine the free surface position (Quaranta et al, ). The Reynolds shear stresses ( RS ) in the momentum equations τ i , j were modelled by means of the turbulent dynamic viscosity μ t :

τ_{i, j} = - ρ \overset{v_{i}^{'} v_{j}^{'}}{true} = μ_{t} ((), \frac{\partial V_{i}}{\partial x_{j}} + \frac{\partial V_{j}}{\partial x_{i}}) - \frac{2}{3} ρ k δ_{i j},

where μ t is the turbulent dynamic viscosity, ρ is water density, k is the turbulent kinetic energy (TKE), and δ ij is the Kronecker delta (Ansys Fluent, ).…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, the design of a fishway has to take into account the biological characteristics of the migrating fish, that is, their swimming capability, size, and fish reaction to external stimuli such as turbulence, flow acceleration, and velocity (Clay, 1995; Rodriguez, Agudo, Mosquera, & Gonzalez, ; Katopodis & Gervais, ; Katopodis & Williams, ; DWA‐German Association for Water, Wastewater and Waste, ). In Clay (1995), Katopodis and Gervais (), Katopodis and Williams (), Plaut (), Puertas et al (), Silva et al ( and ), Tuhtan et al (2018), Tritico and Cotel (), Quaranta, Katopodis, Revelli, and Comoglio (), the interaction between fish and flow field in fish passes has been investigated and discussed.…”

Section: Introductionmentioning

confidence: 99%

“…The formation of recirculation zones, which are too large and which drive the jet in the direction of the baffle, has to be avoided (Wang et al, ). Hence, 5% slope is considered appropriate for multispecies rivers to limit species selectivity and to ensure a predominant 2D flow field (Marriner, Baki, Zhu, Cooke, & Katopodis, ; Quaranta et al, ), whereas 10% is a value used to limit fishway construction costs, especially when passage of larger salmonids or other species of similar swimming ability and behaviour is expected.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of bed slope on the flow field of vertical slot fishways

Quaranta

Katopodis²,

Comoglio

2019

River Research & Apps

Self Cite

View full text Add to dashboard Cite

Vertical slot fishways (VSFs) are the most efficient and least selective typology of technical fish passage, due to their ability to remain effective even when significant upstream and/or downstream water level fluctuations occur. Fishway construction costs can be reduced by increasing its bed slope, but this affects the flow field inside the pools, with higher head drops between the basins, as well as turbulence levels and flow velocities, which may affect fish passage. In light of this, a VSF was investigated by 3D numerical simulations to identify the possible effects of the bed slope (using values from 1.67% to 10%) on the flow field and subsequent implications for fish passage. A particular focus was devoted to cyprinind species, but the results can be extended to other species of similar swimming abilities and, therefore, be applicable to multispecies rivers. Flow velocity and turbulence values such as turbulent kinetic energy and Reynolds stresses were analysed from a fish passage perspective in relation to threshold values derived from previous studies. Pool areas where turbulence values are compatible with fish ability and behaviour were quantified. Maps of the location of fish-friendly zones in the VSF pools were produced and can constitute a reference for practical applications in fishway design. The flow field generated with bed slopes lower than 6.67% is more compatible with fish swimming capabilities, because it exhibits a predominantly 2D behaviour and more suitable hydraulic conditions, whereas at higher slopes, turbulence levels in the pools increase.

show abstract

Advances in Alternative Sources of Energy

Tyagi

2021

Energy

View full text Add to dashboard Cite

Turbulent flow field comparison and related suitability for fish passage of a standard and a simplified low‐gradient vertical slot fishway

Cited by 57 publications

References 25 publications

Assessment of Retrofitted Ramped Weirs to Improve Passage of Potamodromous Fish

Assessment of Retrofitted Ramped Weirs to Improve Passage of Potamodromous Fish

Effects of bed slope on the flow field of vertical slot fishways

Advances in Alternative Sources of Energy

Contact Info

Product

Resources

About