Water hammer flow oscillations not stopping even after 10000s

Question

In my model a pump discharging to a elevated reservoir and stop within 10 s but the oscillations due to the water hammer remain even after 10000 s and not damped much.

Scott Kampa · Answer

Hello subhan, 
 
This can happen in models with no demand and no secondary source for demands to be satisfied. HAMMER assumes that demands are pressure dependent, so if the pump shuts down and there is no other source for demands to be satisfied, the pressure way will not dissipate or will dissipate slowly. This is because there is basically no flow in the system, just a pressure wave bouncing from one end of the system to the other. The following link has some additional information on this: communities.bentley.com/.../20218.pressure-wave-not-dampening-with-no-demand-applied-at-junction-solution-500000085346 . 
 
Additional information about your system may be needed in order to go further into this. There are two options for sharing your model files on Communities. If you would like the files to be visible to other members, compress the files into a zip file and upload them as an attachment using the ‘Advanced Reply editor’ before posting. If your data is confidential, you can follow the instructions in the link below to send it to us via Bentley Sharefile. Files uploaded to Sharefile can only be viewed by Bentley. 
 
 communities.bentley.com/.../7079.be-communities-secure-file-upload 
 
If you upload the model to Sharefile, please post here with the name of the file so that we know it is available. 
 
Regards, 
Scott Kampa 
Bentley Technical Support