Dynamic Lift on an Artificial Static Armor Layer During Highly Unsteady Open Channel Flow

Spiller, Stephan Mark; Rüther, Nils; Friedrich, Heide

doi:10.3390/w7094951

Cited by 10 publications

(8 citation statements)

References 29 publications

(42 reference statements)

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“…The casting technique has been employed recently to investigate the significance of interfacial hydraulics on the flow field over water worked gravel beds or the near bed turbulent flow field over complex (partly artificial) rough beds [e.g., [9][10][11][12][13][14][15]. The studies focusing on the significance of the interfacial hydraulics on the flow field made use of the fact that the surface layer of water worked beds can be reproduced with a high level of accuracy and that, at the same time, the porosity of the cast equals zero below the roughness troughs ( Fig.…”

Section: Casting Techniquesmentioning

confidence: 99%

Hydraulic physical model production with Computer Numerically Controlled (CNC) manufacturing techniques

et al. 2018

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Physical models are a well-accepted tool in hydraulic engineering, allowing for the detailed characterisation of flow processes and the validation of structure designs with complex boundary conditions. The methods used to construct physical models typically produce a surface roughness which does not necessarily scale with the surface roughness of the prototype. In this context, this paper discusses novel construction methods allowing a detailed reproduction of roughness elements in scaled models, such as Computer Numerically Controlled (CNC) manufacturing techniques and bed casting techniques. In particular, the present paper details the protocols developed to mill out a correct representation of the complex rock-fractured geometry of a closed channel which was obtained from Terrestrial Laser Scanners. The novelty of this scaled model production is the implementation of optical accesses in a closed (pressurized) hydraulic model, to allow for Particle Image Velocimetry measurements with a minimum impact on the reproduced roughness elements. The effectiveness of this production protocol is discussed in the context of modelling the roughness effects on the flow regime.

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Section: Casting Techniquesmentioning

confidence: 99%

Hydraulic physical model production with Computer Numerically Controlled (CNC) manufacturing techniques

et al. 2018

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“…Casting methods represent a rather classical technique for reproducing surface features by filling a mould with liquified material which is then allowed to harden. Casting has been used, for example, to reproduce gravel bed surfaces and to investigate the influence of bed porosity on flow characteristics [12][13][14][15][16][17][18]. Despite the high accuracy that may be achieved by this technique, it has shortcomings, as the original surface may be destroyed or altered when creating the mould, and because the mould cannot be easily scaled down.…”

Section: Introductionmentioning

confidence: 99%

Technical Note: On the Production and Accuracy of CNC-Manufactured Hydraulic Scale Models

Aberle

Eikenberg

Branß

et al. 2021

Water

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This Technical Note addresses the workflow for the production of hydraulic scale models using a Computer Numerically Controlled (CNC) production technique and investigates the possibilities to accurately reproduce topographical roughness features. Focusing on the construction of three scale models of unlined rock blasted tunnels, their accuracy is evaluated based on the comparison of differences between scaled prototype point clouds obtained by terrestrial laser scanning, spatially filtered meshes that served as input for the milling of the models, and digital twins of the constructed models that were created by Structure from Motion photogrammetry. The direct comparison between the point clouds and meshes as well as the comparison of derived statistical parameters show that the models could be reproduced with a high degree of accuracy. Observed deviations between the point clouds of the milled models and the milling meshes, as well as the scaled original point cloud, are identified and discussed in light of the production technique and the accuracy of the applied methods for the comparison.

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“…Available literature on armoring also indicates that lift is as important as shear stress when estimating a particle's threshold condition. Key factors in dynamic lift include the ramping duration and the ramping rate, as well as the total increase in discharge [25].…”

Section: Discussionmentioning

confidence: 99%

Bed-Sediment Transport Conditions along the Sagavanirktok River in Northern Alaska, USA

Toniolo

2020

Water

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This manuscript presents a study in predicting bed-sediment transport rates along the Sagavanirktok River in Alaska. Extensive field activities took place to accomplish this goal: four hydro-meteorological stations were installed in a 150 km reach along the river in summer 2015. During the same year, pits were excavated near the stations, and in subsequent summers, the pits were surveyed multiple times in conjunction with taking discharge measurements. Water slope was measured and bed sediment was characterized. Site-specific relationships between water levels and cross-section water depths were developed. Volume change between consecutive surveys was calculated, and main flood events between surveys were identified. Finally, the first bed-sediment transport equations valid for the Sagavanirktok River were developed. Considering the intrinsic error in sediment transport predictions, the agreement between predicted and measured sediment transport values is good. These equations could be used by resource managers when predicting the expected time for an excavated material site in the Sagavanirktok River to refill.

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Dynamic Lift on an Artificial Static Armor Layer During Highly Unsteady Open Channel Flow

Cited by 10 publications

References 29 publications

Hydraulic physical model production with Computer Numerically Controlled (CNC) manufacturing techniques

Hydraulic physical model production with Computer Numerically Controlled (CNC) manufacturing techniques

Technical Note: On the Production and Accuracy of CNC-Manufactured Hydraulic Scale Models

Bed-Sediment Transport Conditions along the Sagavanirktok River in Northern Alaska, USA

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