in water hammer for pump start-up case,

in water hammer for pump start-up case, I am encountering following error " steady state flow must be zero while running pump start-up case" please advise how to resolve this, I don't find any flowrate I keyin for SS case

  • Hello Tausif,

    I have moved your post to the OpenFlows Forum.

    Do you intend to model a pump start up case where the pump is initially off, then turns on during the transient simulation? If so, then when the transient pump type is selected, the initial flow through the pump must be zero. First, ensure that the pump's "initial status" field is set to off, and that the flow through the pump (as seen in the Results section of the pump properties) is zero. If the pump is set to be off and the flow is not, zero, check for unbalanced network conditions. (such as flow being forced through the turned-off pump in order to satisfied assumed demands, in which case you may need to model a shut down followed by start up)

    If the pumps' initial conditions flow is zero and you still get this message, check the transient calculation options and make sure "specify initial conditions" is set to "false" (so that it uses the steady state initial conditions, instead of user-entered initial conditions).

    There are some additional considerations when modeling a pump startup transient event, which you can read more about here: Modeling a Pump Start-Up Transient Event in HAMMER

    If the above does not help and you need further assistance, please provide a copy of the model for review: Sharing Hydraulic Model Files on the OpenFlows Forum


    Jesse Dringoli
    Technical Support Manager, OpenFlows Products
    Bentley Communities Site Administrator
    Bentley Systems, Inc.