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Thread: unbalancing due to 1 pipe

  1. #1
    Member
    Join Date
    Dec 2016
    Posts
    57

    unbalancing due to 1 pipe

    I am preparing a mode
    The model run ok, balances after 32 iteartions.
    When I add 1 pipe connected to one node with demand zero, then the model does not balance. I increase to 200 iteration but still not working. WHat copuld be the problem?

  2. #2
    Forum Moderator

    Innovyze Employee



    Innovyze Employee



    Join Date
    May 2015
    Posts
    417
    Vladimir,

    It appears, something is causing the flows in that pipe to have difficulty converging. EPANET starts every pipe at 1 ft/s velocity so even a pipe with no demands has a non zero flow in it initially.

    Try adjusting your simulation options as follows to get convergence.

    General Tab:
    Trials: 200
    Accuracy: 0.001
    Unbalanced: Continue
    Extended Run: 50
    (click if need larger image)
    Simulation Options - For Convergence.jpg

    Advanced Tab:
    Status Check Frequency: 2
    Max Status Check Iteration: 10
    Relaxation Factor: 0.6
    Damping: 0.01 (i.e. at 10X your accuracy on the general tab)
    (click if need larger image)
    Simulation Options - Advanced.jpg

    This should help it converge and resolve your issue.

    If it still fails to converge make sure to set your report options to show a full status report and warning messages as this will tell you more about why it is having issues:
    (click if need larger image)
    Full Report with Warning Messages.png

    If you still have difficulties please let us know.

    Patrick Moore

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