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  • 1.  modeling transient pressure pipe flow with a Priessmann slot

    Posted 10-25-2016 05:31 PM

    Folks:

     

    Has anyone modeled transient flow under pressure, using Priessmann theory, through a tunnel with an adverse bottom slope? Does the method have any known limitations for such an application?

     

    Thanks in advance.

     

    Mark M Wilsnack

    Mark M. Wilsnack, P.E.

    Principal Engineer

    Hydraulic Design Unit

    Hydrology & Hydraulics Bureau

    South Florida Water Management District

     



  • 2.  RE: modeling transient pressure pipe flow with a Priessmann slot

    Posted 10-26-2016 04:27 AM

    Hi Wilsnack,

    If the transient flow is always pressurized, the classic approach is Method of Characteristics (MOC). If you are trying to do mixed flows, i.e. free surface flow and pressurized flow, Preissmann slot method is one of the most popular methods for these flows. As far as I know, the limitations are as follows.

    1. It does not include air effects.

    2. There are no firm guidelines for determining the proper slot width, accounting for both wave speed and numerical stability.

    3. It cannot calculate those cases where sub-atmospheric pressure flow may exist.

    4. it cannot reflect the interface hydrodynamics.

    Hope this helps. Let me know if you are interested in further discussions.

    Biao

    ------------------------------
    Biao Huang S.M.ASCE
    Edmonton AB

    Original Message


  • 3.  RE: modeling transient pressure pipe flow with a Priessmann slot

    Posted 10-26-2016 04:28 AM

    Hi Mark,

    There is quite a bit of literature on Priessmann slot. In addition to issues related to mass conservation, wave celerity and subatmospheric pressure, the solution may become unstable if the solve does not have algorithm to handle sharp interfaces, for example a moving pressure wave. Not sure about your specific case, an adverse slope may contribute to the development of traveling hydraulic jump like features and make the solution unstable.

    ------------------------------
    Liaqat Khan P.E., D.WRE, M.ASCE
    Redmond, WA 90852


    Original Message


  • 4.  RE: modeling transient pressure pipe flow with a Priessmann slot

    Posted 10-26-2016 12:52 PM

    Re literature on Priesmann slot.   Can you recommend an article that would serve as a good introduction to it?

    ------------------------------
    Dennis Beckmann BCEE., P.E., M.ASCE
    Beckmann Environmental Consulting LLC
    Houston TX

    Original Message


  • 5.  RE: modeling transient pressure pipe flow with a Priessmann slot

    Posted 10-26-2016 04:29 AM

    Hi Wilsnack,

    If the transient flow is always pressurized, the classic approach is Method of Characteeristics (MOC). If you are trying to do mixed flows, i.e. free surface flow and pressurized flow, Preissmann slot method is one of the most popular methods for these flows. As far as I know, the limitations are as follows.

    1. It does not include air effects.

    2. There are no firm guidelines for determining the proper slot width, accounting for both wave speed and numerical stability.

    3. It cannot calculate those cases where subatmospheric pressure flow may exist.

    4. it cannot reflect the interface hydrodynamics.

    Hope this helps. Let me know if you are intrested infurther discussions. 

    Biao 

    ------------------------------
    Biao Huang S.M.ASCE
    Dept. of Civil and Environmental Engineering
    University of Alberta
    Edmonton AB, Canada


    Original Message


  • 6.  RE: modeling transient pressure pipe flow with a Priessmann slot

    Posted 10-26-2016 09:29 AM

    You might want to contact Karen Ridgeway at Applied Science, Inc. (ASI).  She helped to develop "TAP"...I believe it stands for Transient Analysis Program. 

    Applied Science Home

    Good luck! :)

    ------------------------------
    Jennifer Morreale P.E., CFM, M.ASCE
    Project Engineer
    Hubbell Roth & Clark
    Detroit MI
    (313) 463-4248

    Original Message


  • 7.  RE: modeling transient pressure pipe flow with a Priessmann slot

    Posted 02-07-2017 12:56 PM
    Hi Mark,

    Recently I published few papers related to transient flows from pressurized to free surface in a circular and rectangular ducts. I am sending you the links. 
    Please don't hesitate to contact me for further information.

    Regards,
    Hamid
    Email: h.bashiri.a@...

    http://ascelibrary.org/doi/abs/10.1061/(ASCE)HY.1943-7900.0000953
    http://ascelibrary.org/doi/abs/10.1061/(ASCE)HY.1943-7900.0001200
    http://iahr.tandfonline.com/doi/abs/10.1080/00221686.2015.1060272


    ------------------------------
    Hamid Bashiri Ph.D., A.M.ASCE
    Postdoctoral Researcher
    Houston TX
    324366 9267
    ------------------------------

    Original Message


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