Physical-scale model designs for engineered log jams in rivers

Gallisdorfer, Michael S.; Bennett, Sean J.; Atkinson, Joseph F.; Ghaneeizad, Seyed Mohammad; Brooks, Andrew Pattrick; Simon, Andrew; Langendoen, Eddy J.

doi:10.1016/j.jher.2013.10.002

Cited by 53 publications

(44 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following Gallisdorfer et al (2014), dimensional analysis indicates that the primary scaling relationship for the model is the Froude number Fr, where the ratio (subscript r) between the field prototype (subscript p) and physical model (subscript m) is set to unity,…”

Section: Methodsmentioning

confidence: 99%

“…Gallisdorfer et al (2014) reviewed the basis for scaled physical models of ELJs and presented the necessary relations for analyzing the introduction of ELJs into the Big Sioux River, SD, USA, as an example application. The Big Sioux River is a relatively low sinuosity river with a very fine sand bed flowing across glacial outwash and alluvial sediments where the primary land use in the watershed is agriculture (row crops and pasture).…”

Section: Introductionmentioning

confidence: 99%

“…The proposed installations of ELJs along this river are to reduce bank erosion and to decrease suspended sediment fluxes to downstream environments, which have adversely affected fish and aquatic life within the river (SDDENR, 2014). Using the 1.5-year recurrence interval flow rate, spatially averaged dimensions of the river channel, and characteristics for the available wood, Gallisdorfer et al (2014) provided the scaling relations required to construct fixed-and movablebed physical models and the design of two different ELJ structures. The focus of the current paper is to present experimental findings for the fixed-bed model where two types of ELJs were deployed alone and in groups of two or three of the same structure.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Flow, turbulence, and drag associated with engineered log jams in a fixed-bed experimental channel

et al. 2015

Self Cite

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Flow, turbulence, and drag associated with engineered log jams in a fixed-bed experimental channel

et al. 2015

Self Cite

View full text Add to dashboard Cite

“…In this study, the ELJ flume experiments in [10,30] were simulated and analyzed. The water depth was H = 114 mm, and the flume width was B = 1900 mm.…”

Section: Geometry Preparation and Mesh Generationmentioning

confidence: 99%

“…The three geometric representations include the fully-resolved model (no simplification in geometry), the porosity model and solid barrier (i.e., treating the ELJ as an impervious box). The simulation case was based on the flume experiments for ELJ in [10,30]. In the following, the computational models will be introduced first.…”

Section: Introductionmentioning

confidence: 99%

Effects of Different In-Stream Structure Representations in Computational Fluid Dynamics Models—Taking Engineered Log Jams (ELJ) as an Example

Liu

2017

Water

View full text Add to dashboard Cite

Abstract:In-stream structures contribute greatly to the biodiversity in streams and play an important role in restoring and protecting rivers. They usually have complex geometries. To evaluate their impact and effectiveness, computational models are increasingly used. However, how to faithfully represent them in computer models remains a challenge. Often, simplifications have to be made. This work evaluated the effects of geometric simplification of an example in-stream structure, an engineered log jam (ELJ), in computational models. Three different representations were considered, namely full resolution, the porous media model and the solid barrier model. The turbulent flow was resolved with large eddy simulation (LES). First, the simulations were validated with a physical experiment in a flume. Then, the results from the three models were compared and analyzed on various aspects related to the stability and functionalities of the structures. Unsurprisingly, it is found that the porous media model and the solid barrier model, which are computationally economic, can describe the flow dynamics only to some extent. From the calibration of drag force and wake length, we found that the equivalent grain size d 50 in the porosity model should scale as the key element diameter for the simulated ELJ. A wake length scale analysis was performed for the semi-bounded flow around this in-stream structure near the bank. The length estimator in the literature for unbounded vegetation patches can be used with modifications. The results also show that the flow passing through the porous in-stream structure has a significant impact on mean velocity, turbulence kinetic energy, sediment transport capacity and integral wake length. Since geometrically-fully-resolved simulations are not currently feasible for engineering practices, the following suggestions are made based on this study. If the near-field and wake are important for the purpose of the structure, the well-calibrated porosity model seems to perform better than the solid barrier model. However, care needs to be taken when interpreting the results because this work also identified substantial loss of physical information with the porosity model. When the emphasis is the far field away from the structure, both the porosity model and the solid barrier model give comparable results.

show abstract

Physical and Numerical Modelling of Large Wood and Vegetation in Rivers

Bertoldi¹,

Ruíz-Villanueva²

2017

Gravel‐Bed Rivers

View full text Add to dashboard Cite

Physical-scale model designs for engineered log jams in rivers

Cited by 53 publications

References 25 publications

Flow, turbulence, and drag associated with engineered log jams in a fixed-bed experimental channel

Flow, turbulence, and drag associated with engineered log jams in a fixed-bed experimental channel

Effects of Different In-Stream Structure Representations in Computational Fluid Dynamics Models—Taking Engineered Log Jams (ELJ) as an Example

Physical and Numerical Modelling of Large Wood and Vegetation in Rivers

Contact Info

Product

Resources

About