TUFLOW 2D Hydraulic Structures: Difference between revisions
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<li>Digitise <font color="blue">2d_lfcsh</font> or <font color="blue">2d_fcsh_</font> inputs using either a line or polygon feature. When applying form loss coefficients the best approach is to view the structure as a collection of 2D cells representing the whole structure, rather than being too specific about the representation of each individual cell:
* Line features will apply the form loss value to a single row of cells across the waterway. The TUFLOW form loss input should be entered representing the total value (eg. FC = 0.2).
* Polygon features will distribute the form loss between multiple cells across the width of the bridge and across the waterway. Due to this, the TUFLOW form loss input should be entered as the total value per unit width in the direction of flow (eg. FC = 0.2/20m = 0.01).</li>
<li> Flow widths (conversely, blockage factors) and flow height should be updated in the <font color="blue">2d_lfcsh</font> or <font color="blue">2d_fcsh_</font> inputs. This information is used to refine the structures flow area when the model grid resolution isn't fine enough to accurately do so already.
<li>The head loss across key structures should be reviewed, and if necessary, benchmarked against other methods (Recorded calibration data, HEC-RAS). Note that a well-designed 2D model will be more accurate than a 1D model, provided that any “micro” losses are incorporated.</li>
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