TUFLOW Message 1991: Difference between revisions
Content deleted Content added
Created page with '{{TUFLOW_Message |tuflow_message=WARNING 1991 - ",a,": Negative depth at Node ",a,": "," y =",f7.2," Bed =",f7.2," Iter = |alt_msg=WARNING 1991 - ",a,": Negative depth at Node ...' |
No edit summary |
||
Line 3:
|alt_msg=WARNING 1991 - ",a,": Negative depth at Node ",a,": "," y =",f7.2," Bed =",f7.2," dh =
|type=[[WARNING]]
|message_desc=Numerical solution has resulted in a negative depth at 1D node. This indicates that the model is unstable in this area. There are a number of possible reason for this to occur, the most common are:<br>
Incorrect bed levels upstream or downstream;<br>
A large change in cross-sectional area;<br>
Very steep channel entering a gently or advers grade channel;<br>
Sudden change in flow area (for example a culvert width entered in mm not m, 1200 not 1.2);
Issues with 1D/2D linking (incorrect use of Z flag on culvert inlet / outlet);
To high a timestep; and<br>
Low nodal area.<br><br>
For a more detalied description on identify the start of instability please see Section 8.1.3 Tips for an Unhealthy 1D Domain and Section 8.1.4 Tips for Unhealthy 1D/2D Links of the TUFLOW manual (reference for 2010 version).
|suggestions=Identify start of instability and cause of instability and fix! See references above for guidance.
|discussion_page=* [[Talk:TUFLOW Message 1991|Discuss Message 1991]]
|link3=''
| |||