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Air Valve Ingress/Egress Flowrates

I have a question regarding the TechNote on Air Valve elements. (https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/3400/modeling-reference---air-valves)  

Specifically the section on Reporting and the Transient Analysis Output Log.  I see this provides results for the CURR. FLW# which is defined in the note as the flow through the end point at the end of the transient simulation (last time step, current flow).  Is this information available somewhere for different time steps in the calculation?  Interested in learning the maximum flowrate of air into and out of an ARV during the simulation.  Is this information available in the reporting somewhere?  I assume this is the information provided in the Transient Analysis Output Log?  But this information is air flow in the pipeline and not free-air at the valve opening?

I also found a previous discussion on this topic that is now locked (https://communities.bentley.com/products/hydraulics___hydrology/f/haestad-hydraulics-and-hydrology-forum/145265/follow-up-to-service-request-7000721384-pertaining-to-air-ingress-velocity/441438#441438) which mentions potential future enhancements to directly report free-air flowrate and velocities.  Has there been any updates to address this enhancement?

Thanks,

Brian

  • Brian,

    The answer to your question is in the third paragraph under the "Reporting" section of the air valve modeling reference article. First, enter a number for the "report period" property of the air valve (for example "10" means at every 10 timesteps) and ensure that the transient detailed report option is enabled in the transient calculation options. Re-compute the transient simulation and open the Transient Analysis Detailed Report (from the Report > Transient Reports menu). Scroll to the very bottom (you may need to page up a bit from there) and you should see a table of various extended results for the air valve(s) including "air-flow". A positive value for "air-flow" indicates outflow and a negative value indicates inflow.

    We are still looking into exposing these results in the "Extended node data" tab of the Transient Results Viewer (instead of having to use the text report. Also, the air flow rate in the text report is still at pipeline pressure (see the diagram I put in the article to explain this)


    Regards,

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