TUFLOW 2D Hydraulic Structures: Difference between revisions

The TUFLOW 2D solution automatically predicts the majority of “macro” losses due to the expansion and contraction of water through a constriction, or around a bend, provided the resolution of the grid is sufficiently fine ([http://www.tuflow.com/Download/Publications/Flow%20Through%20an%20Abrupt%20Constriction%20-%202D%20Hydrodynamic%20Performance%20and%20Influence%20of%20Spatial%20Resolution,%20Barton,%202001.pdf Barton, 2001]; [http://www.tuflow.com/Download/Publications/Modelling%20of%20Bends%20and%20Hydraulic%20Structures%20in%20a%202D%20Scheme,%20Syme,%202001.pdf Syme, 2001]; [http://www.tuflow.com/Download/Technical_Memos/Modelling%20Bridge%20Piers%20in%202D%20using%20TUFLOW.pdf Ryan, 2013]). Where the 2D model is not of fine enough resolution to simulate the “micro” losses (e.g. from bridge piers, vena contracta, losses in the vertical (3rd) dimension), additional form loss coefficients and/or modifications to the cells widths and flow height need to be added. This can be done by using flow constrictions listed above.

The TUFLOW form loss coefficients can be derived from information in publications such as ''Hydraulics of Bridge Waterways'' ([http://www.ciccp.es/ImgWeb/Castilla%20y%20Leon/Documentaci%C3%B3n%20T%C3%A9cnica/Hydraulics%20of%20Bridge%20Waterways%20(1978).pdf FHA, 1973]). For example, backwater caused by introduction of piers in a bridge constriction is dependent on the ratio that the area of the piers relative to the gross area of the bridge opening, the type of piers (or piling in the case of pile bents) and the angularity of the piers with the direction of flood flow.