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Modeling a well in WaterCAD

Hello,

How to model a well in watercad having a known constant outflow? 

thank you

  • If there are only fixed demands downstream then a reservoir at the well location (with no negative demand anywhere) will produce a flow equal to the sum of the downstream demands. You would not be able to use a negative demand in this case without having another boundary condition (reservoir or tank) to either accept access flow or supply a deficit. 


    Regards,

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

    Answer Verified By: H 

  • Ohh that’s it!! 
    I am sorry to bother but shouldn’t an FCV do the job? 

  • An FCV will throttle to reduce the flow but that only works if a headloss causes a drop in flow. If you have a model with fixed demands, the flow from the source is essentially fixed and will always be equal to the sum of the downstream demands. Attempting to use an FCV in such a case would result in an ill-conditioned matrix. See more here: Using a Flow Control Valve (FCV)


    Regards,

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

  • Deal thank you so much fo your help!!
    So my only option is to get the pump info and work as Joeri Legierse mentioned

  • With only fixed demands downstream, a reservoir + pump will produce a flow equal to the sum of the demands (which I assume is 65 l/s) and will add head so that you can simulate pressures in the network. If you have an estimate of the amount of head the pump will add, you can use the "design point" pump type and enter that head with the corresponding 65 l/s flow point. It would be best to get information from the pump manufacturer. Plus you may need information about the well water level and drawdown effects. See the third link I had provided earlier: Accounting for well drawdown


    Regards,

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