TUFLOW 1D2D Boundary Configuration Guidance: Difference between revisions

Content deleted Content added
 
(One intermediate revision by the same user not shown)
Line 52:
 
 
The modelled flow rates are shown in the figure below. AsThe canfigure be seendemonstrates, comparable peak flow rates are obtained regardless of the cell size (i.e. cell size convergence is demonstrated). The stability in the 1m cell size case has been improved markedly, though there are still some oscillations at low flows. <br>
 
[[File:1D2D Model Stability 005.png|500px]]<br>
Line 92:
TUFLOW HPC inflow boundaries may experience recirculation when a uniform elevation is defined along the length of the boundary. This problem may also occur along HX boundaries in 1D-2D linked models that outflow from the 1D to the 2D domain. This is not a common configuration, though may occur when using a 1D channel to convey the flow from a dam break or similar along a defined channel onto floodplains in the 2D domain.
 
Consider setting up the 1D-2D linking shown in Figurethe 1.5figure Thebelow; the HX boundary “HXb1” shown in red is connected at each end to the same 1D node, whereas the remaining HX boundaries shown in purple are connected at each end to different 1D nodes. In the case that the flow is leaving the 2D domain to enter the 1D channel, the boundary is usually stable without energy correction, however for the reverse case, under high flow velocity conditions, the boundary may display instability or recirculation. If this does occur the problem may be remedied via an energy correction, using the command
<font color="blue"><tt>HPC Boundary Approach </font> <font color="red">==</font> Method B</tt>. Note that this will likely cause water level lines to display some discontinuity between the 1D and 2D domain across the boundary.