Innocenti, Lorenzo
[Verfasser:in]
;
Aberle, Jochen
[Mitwirkende:r];
Solari, Luca
[Mitwirkende:r]
Large Wood Dynamics in Sharp River Bends: Experimental and Numerical Investigations ; Schwemmholzdynamik in stark gekrümmten Fließgewässerabschnitten - experimentelle und numerische Untersuchungen
Titel:
Large Wood Dynamics in Sharp River Bends: Experimental and Numerical Investigations ; Schwemmholzdynamik in stark gekrümmten Fließgewässerabschnitten - experimentelle und numerische Untersuchungen
Beteiligte:
Innocenti, Lorenzo
[Verfasser:in]
Erschienen:
TU Braunschweig: LeoPARD - Publications And Research Data, 2022-10-26
Anmerkungen:
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Beschreibung:
In last decades, the role of large wood (LW) in rivers was largely investigated due to the ecological importance for river habitats, and due to the associated potential hazards to humans and infrastructures, resulting an additional component of fluvial hydraulics. Despite recent research, knowledge of the dynamics of transported wood elements is still incomplete, particularly in modelling the effect of secondary currents on the LW dynamics. The present PhD research aims to enhance the knowledge on the transport of LW in sharp river bends by finding answers to the two main research questions: the identification of the main variables that influence the phenomenon, and assessing the capability of 2D depth-averaged models in reproducing effects of secondary currents on wood trajectories. A combined physical and numerical approach is used for this purpose. Physical model tests were performed in order to investigate the influence of (i) LW element dimensions, (ii) the approaching position of LW to the curve, and (iii) the initial orientation of LW, on the wood trajectories in a sharp bend. The analysis of experiments was conducted by considering the trajectories of wood pieces along the bend and providing statistical results. Moreover, experiments were analyzed by applying a mathematical model in order to provide the drag coefficient for floating LW subjected to a helical flow. For the simulation of secondary current effects, the 2D depth-averaged model “Iber-Wood” was enhanced and tested by simulating two experimental setups and a river-scale case study. The main results of the present work include the individuation of the main variables that influenced the LW trajectories in sharp river bends, the calculation of drag coefficients for a floating LW, and the improvement of the Iber-Wood model in simulating secondary current effects. In addition, two nondimensional coefficients are provided: the coefficient of variation for expressing the trajectory deviation along a bend, and the coefficient of similarity for ...