Engineering Commons^™

Large-Eddy Simulations Of T-Shaped Open-Channel Confluences With Different Downstream Channel Widths, Pedro Xavier Ramos, Laurent Schindfessel, João Pedro Pêgo, Tom De Mulder

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Confluences of open-channel flows are common in nature as well as in urban drainage networks and in hydraulic structures. The complex hydrodynamics is often studied in schematized, right-angled confluences. In this paper, the influence of the downstream channel width onto time-averaged and turbulent flow features will be investigated numerically, based on Large-Eddy Simulations. For one flow situation, i.e. flow ratio and downstream Froude number, two geometries will be compared: a discordant width case, which was studied experimentally by Yuan et al. (2016) in a flume with a wider downstream channel than the upstream mean and tributary channels, and the corresponding …

Composite Experimental And Numerical Modeling Of Arced Labyrinth Weirs, Seth Thompson, Blake Tullis

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Arced labyrinth weirs are a viable option for existing spillway retrofit due to their increased flow capacity. This study supplies additional arced labyrinth weir hydraulic design empirical data and uses this data to validate a numerical model (utilized Flow-3D) of the same experimental setup. The dimensionless discharge coefficient relationship is presented for the physical model, potential errors due to physical model crest referencing are discussed, and the relative and absolute errors along with a grid convergence study are given for the numerical model.

Comparison Of Modelling Approaches For Development Of Discharge Rating Curves For Spillway/Bridge Combinations, Nathan Young

International Junior Researcher and Engineer Workshop on Hydraulic Structures

When estimating spillway discharge rating curves, engineers can use a variety of methods such as empirical equations, one- (1D) or two-dimensional (2D) hydraulic computer models, or a combination thereof; however, conservative assumptions are often applied to such methods. The use of three-dimensional (3D) computational fluid dynamics (CFD) models is an alternative modelling approach that can often better estimate spillway discharge rating curves, especially for complex flow situations. In this study, the results of 3D CFD models are compared to estimates of spillway discharge rating curves developed with a combination of empirical equations and other hydraulic computer models for spillway/bridge combinations. …

A Numerical Study Of The Lateral Hyporheic Flow About A Channels Confluence, C. Gualtieri

International Congress on Environmental Modelling and Software

Stream and pore waters continuously interact and mix within streambeds due to spatial and temporal variations in channel characteristics. This mixing is termed as hyporheic exchange and the zone where groundwater and stream water are mixing is called hyporheic zone, which can greatly affect water quality is both surface and subsurface water systems. Typical examples of hyporheic fluxes are those under bedforms, intra-meander or across point bar deposits, while the lateral and vertical hyporheic exchanges about a riverine confluence was almost never investigated.

The paper presents some results of a numerical study carried out to investigate the basic features of …