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You searched for +publisher:"Universiteit Utrecht" +contributor:("Cartigny, M.J.B."). Showing records 1 – 2 of 2 total matches.

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Universiteit Utrecht

1. Vellinga, A.J. Morphodynamics of bedforms in a supercritical-flow regime: a depth-resolved numerical modelling approach.

Degree: 2014, Universiteit Utrecht

Both open-channel flows and density currents are able to create supercritical-flow bedforms. The morphodynamics of these supercritical-flow bedforms are, however, still poorly understood. This is mainly due to a lack of measurements of flow processes occurring within these types of flows. Cyclic steps have successfully been simulated in open-channel flow using a depth-resolved numerical model. The equilibrium conditions at which certain supercritical-flow bedforms are stable are investigated. The temporal variation in Froude number is indicative of at which conditions cyclic steps are in a macroscopic equilibrium at a variability of grain sizes, discharges and sediment concentrations. The depth-resolved model provides insight into the dynamic interaction between velocity structure, shear stresses, and sediment concentrations within the flows and resulting erosion and deposition patterns, which, in their turn affect the flow-properties again. The velocity structure downstream of a hydraulic jump displays highest flow velocities near the bed, whilst lowest or even negative velocities are located at the top of the flow, causing the flow to remain exerting shear stresses on the bed even after the hydraulic jump. The sediment concentrations within the flow only decrease after a 30 second, or half a meter lag, causing most of the deposition to take place at the last two-thirds of subcritical region of the flow. The resulting depositional pattern consists of upstream-dipping backset laminations deposited on the stoss-side of the bedform, cross-cut by the erosive surface of the lee-side of the cyclic step, this interplay between erosion and deposition also causes an upstream migration of the cyclic steps. Advisors/Committee Members: Eggenhuisen, J.T., Cartigny, M.J.B..

Subjects/Keywords: morphodynamic; supercritical; flow; bedform; bedforms; cyclic step; cyclic steps; RANS; depth-resolved; numerical; model

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Vellinga, A. J. (2014). Morphodynamics of bedforms in a supercritical-flow regime: a depth-resolved numerical modelling approach. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/301315

Chicago Manual of Style (16th Edition):

Vellinga, A J. “Morphodynamics of bedforms in a supercritical-flow regime: a depth-resolved numerical modelling approach.” 2014. Masters Thesis, Universiteit Utrecht. Accessed April 18, 2021. http://dspace.library.uu.nl:8080/handle/1874/301315.

MLA Handbook (7th Edition):

Vellinga, A J. “Morphodynamics of bedforms in a supercritical-flow regime: a depth-resolved numerical modelling approach.” 2014. Web. 18 Apr 2021.

Vancouver:

Vellinga AJ. Morphodynamics of bedforms in a supercritical-flow regime: a depth-resolved numerical modelling approach. [Internet] [Masters thesis]. Universiteit Utrecht; 2014. [cited 2021 Apr 18]. Available from: http://dspace.library.uu.nl:8080/handle/1874/301315.

Council of Science Editors:

Vellinga AJ. Morphodynamics of bedforms in a supercritical-flow regime: a depth-resolved numerical modelling approach. [Masters Thesis]. Universiteit Utrecht; 2014. Available from: http://dspace.library.uu.nl:8080/handle/1874/301315


Universiteit Utrecht

2. Walet, J.J. Hydraulic jumps in turbidity currents - flume experiments.

Degree: 2012, Universiteit Utrecht

The focus of this innovative research is on the effects of grain size and various sediment concentrations on flow dynamics, hydraulic jump characteristics and sediment deposition of experimental turbidity currents. Of special interest is the origin of structureless graded sand beds (Bouma’s Ta), supposed to be the result of an internal hydraulic jump of the high density traction carpet in a 2-phase turbidity current. In this experimental study turbidity currents of different sediment concentration and sediment grain size are created and observed in a flume at the Eurotank laboratory facility at Utrecht University. A hydraulic jump is triggered and flow dynamics and resultant deposits are analyzed. Froude numbers are calculated for 1-phase flows and partial Froude numbers for the bottom layer of 2-phase flows, to determine whether a hydraulic jump occurred. Interpretation of flow dynamics suggested the occurrence of hydraulic jumps, however measurements appeared inadequate to produce reliable Fr’ numbers to support this observation. The supposed hydraulic jump did not produce structureless sand beds; deposits observed were plane bed lamination and low shear lamination (Bouma’s Tb and Td, respectively). Advisors/Committee Members: Postma, G., Cartigny, M.J.B..

Subjects/Keywords: Geowetenschappen; high density turbidity currents, 2-phase turbidity currents, hydraulic jump, hydraulic jump deposits, turbidites, structureless sand bed, Bouma Ta

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Walet, J. J. (2012). Hydraulic jumps in turbidity currents - flume experiments. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/253927

Chicago Manual of Style (16th Edition):

Walet, J J. “Hydraulic jumps in turbidity currents - flume experiments.” 2012. Masters Thesis, Universiteit Utrecht. Accessed April 18, 2021. http://dspace.library.uu.nl:8080/handle/1874/253927.

MLA Handbook (7th Edition):

Walet, J J. “Hydraulic jumps in turbidity currents - flume experiments.” 2012. Web. 18 Apr 2021.

Vancouver:

Walet JJ. Hydraulic jumps in turbidity currents - flume experiments. [Internet] [Masters thesis]. Universiteit Utrecht; 2012. [cited 2021 Apr 18]. Available from: http://dspace.library.uu.nl:8080/handle/1874/253927.

Council of Science Editors:

Walet JJ. Hydraulic jumps in turbidity currents - flume experiments. [Masters Thesis]. Universiteit Utrecht; 2012. Available from: http://dspace.library.uu.nl:8080/handle/1874/253927

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