Revision as of 15:56, 21 November 2022 view source ShuangGao (talk \| contribs) Bureaucrats, Administrators 1,093 edits →Deck Losses and Pressure Flow ← Older edit		Revision as of 17:02, 7 December 2022 view source Pavlina Monhartova (talk \| contribs) Bureaucrats, Administrators 5,395 edits →Deck Losses and Pressure Flow Newer edit →
Line 60: <br> Once water commences to surcharge the bridge deck, TUFLOW BB bridge tests for pressure flow or drowned flow every timestep by choosing the flow regime that gives the lower flow: The pressure flow equation is based on the Section 8.3 "All Girders in Contact with Flow (Case II)" of the Hydraulics of Bridge Waterways (Bradley, 1978), with a default deck discharge coefficient of 0.8. This value can be modified using the 1d_nwk HConF_or_WC attribute. Note that the original hydraulic experiment conducted by Liu (1967) used a flume with a pair of bridge abutments and a deck. This means the impact of both abutments and deck are considered in this approach. ~~Therefore, the~~The entry/exit losses are switched off during the pressure flow calculation to ~~avid~~avoid the overestimation of the contraction/expansion losses. For the drowned flow condition, the BB bridge considers extra energy loss caused by the bridge deck/rails using a deck loss coefficient (default = 0.5) in addition to the entry/exit losses. The deck loss coefficient can be adjusted using the WConF_or_WEx attribute or by specifying the LC (energy loss versus height) table. When pressure flow occurs a flow regime of "P" is reported in the _TSF layer.

1D Bridges: Difference between revisions