Calibration of a dynamic Eulerian-lagrangian model for the computation of wood cylinders transport in shallow water flow

Abstract

A computational Eulerian–Lagrangian model (ORSA2D_WT) is used for modelling the movement of floating rigid bodies on the water surface. The two-dimensional transport is computed with a dynamic approach, modifying existing formulations for the transport of bodies within fluid flows for the case of floating bodies, by adopting suitable added mass, drag and side coefficients. An original formulation for planar rotation is proposed, which includes the effect of the hydrodynamic torque and a resistance term, named added inertia, based on the difference between the angular velocity of the flow and that of the body. The value of the added inertia coefficient is calibrated against experiments made on purpose, involving the transport of a cylinder in a flume with two side obstacles. The calibrated code is applied to a slightly larger set of experiments for its preliminary evaluation. The outcome of the simulations shows that the streamwise and transversal displacements are well modelled, while some inaccuracies arise when considering the cylinder orientation. The effects of the initial conditions on the cylinders' trajectory and rotation are discussed, showing their influence on the evolution of the rotation angles.

Modeling Large Wood Transport in Semi-Congested Regime with Multiple Entry Points

“…The model, applied both to flume and field experiments [23,24], implements a dynamic subroutine to compute wood transport in the hydrodynamic model ORSA2D, i.e., the same hydrodynamic module used as the basis for the Eulerian model presented in the previous paragraphs. The hydrodynamic forces are computed for each cylinder with proper hydrodynamic coefficients [42].…”

“…The coupling of a discrete element method with the 2D solution of the shallow water equation has proven to be a reliable tool to predict large wood transport both in flume and real-scale applications. Such models consider the transport of every single wooden element as a consequence of the velocity [21], or of the forces [22][23][24], exerted by the flow and can compute the displacement and rotation on the water surface of large wood, as well as the interaction and, in some cases, the accumulation at in-line structures and the consequent backwater effect [3].…”

From Grains to Plastics: Modeling Nourishment Patterns and Hydraulic Sorting of Fluvially Transported Materials in Deltas

“…Many studies have applied morphodynamic models to deltaic settings to quantify the partitioning of sediments in distributary networks (e.g., Edmonds & Slingerland, 2008; Hanegan & Georgiou, 2015; Olliver & Edmonds, 2021; Olliver et al., 2020). Other models have been developed to study the transport of drifters like wood (Persi et al., 2019; Mazzorana et al., 2011), oils (Dagestad et al., 2018; Röhrs et al., 2018), and plastics (Atwood et al., 2019), although very few of these models have been applied specifically to deltaic environments. However, none of these models are applicable to all fluvial materials, and comparing material transport between models is likely influenced by differences in modeling choices and assumptions (Baar et al., 2019).…”

A One-Way Coupled Hydrodynamic Advection-Diffusion Model to Simulate Congested Large Wood Transport

“…These models can be defined as Eulerian-Lagrangian models, since they couple the two-dimensional solution of the Shallow Water Equations (SWE, with Eulerian methods, e.g., Finite Volumes) with a Discrete Element approach, properly Lagrangian. Wood elements are entrained and transported according to the hydrodynamic forces [16][17][18][19], computed with appropriate hydrodynamic coefficients [20][21][22], or following a kinematic approach [23]. The three-dimensional effect of the flow can also be considered, especially when focusing on the accumulation of wood at in-line structures [24].…”