Applies To Product(s): Bentley WaterCAD, Bentely WaterGEMS Version(s): 08.11.xx.xx Environment: N/A Area: Modeling Subarea: Original Author: Scott Kampa, Bentley Technical Support Group Error or Warning Message When computing a model, the following user notification is generated: "Disconnected demand nodes detected; hydraulic results are likely to be compromised." How to Avoid This user notification means that there are junctions in the model that have a demand applied to them but are disconnected from a source, such as a tank or reservoir. The cause of this can be from any number of settings in the model. For instance, a pump or valve that is closed will stop flow coming from upstream. If there is no other potential source of flow in the system, the demands will not be satisfied. Other areas that can be checked include tank settings. If a tank is empty, it will not be able to supply flow. You can read more about what happens when a tank becomes empty or full here . Make sure that the orientation of your pumps and/or valves is correct. If you have the incorrect downstream link selected (particularly for a pumps) this will inhibit flow from the element. If you have a hydropneumatic tank in the model, make sure the property field "Treat as Junction" is set to False. If it is set to True, the hydropneumatic tank will act like a junction instead of a potential source of flow. Another item to check is the status and connectivity of pipes in the system. If a pipe is set to be closed, it will cut off flow from upstream. It is also possible that a pipe is not connected to the rest of the system. For instance, a pipe may be overlaying another pipe rather than be connected to it. These types of connectivity issues can be difficult to spot visually, but there is a tool called Network Navigator that can be used to find disconnected segments of a model. See the TechNote on Using Network Navigator for more information.
↧