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Extended period simulation In watergems

I want to understand how extended period simulation works in watergems, not how it is done but how to interpret the results out of that analysis. Why multiplier is used and waht role they have in EPS.

Parents
  • Hi Jay,

    Extended Period Simulation (EPS) type analysis is used when you want to understand the hydraulics of a system over a specified period of time. EPS is basically a series of Steady State runs performed for multiple time steps. When you analyze a model for steady state analysis the hydraulic results obtained are for that particular instance. EPS does this analysis over a period of time.

    When you are viewing the results for an EPS run, you are basically seeing the hydraulics of the system over time.

    In the above image you can see a graph of a junction vs. demand varying over a day (24 hrs). You can see that the time is seen as "4 hrs" and corresponding to that is a demand of 18 L/s. This way you can view the results for all your elements and how are the hydraulics for them over time.

    The multiplier is a factor used to multiply your demand. Typically in water supply system, the demand is not constant for the entire day. The multipliers are specified against each time step so that the proper demand is analyzed for that time step. For example my average demand is 10 L/s but at 6:00 hrs, I require 15 L/s, then we simply specify a factor of 1.5 against 6:00 hrs. Hence the demand at the same junction for 6:00 hrs is 1.5 X 10 = 15 L/s.

    If you are a new user of WaterGEMS, I suggest you go through the Quick Start Lessons available in the Help Section of the software. There are various examples on different features of WaterGEMS which will help you understand its functionality.

    Here are a few articles which are helpful in this regard;

    Run an Extended Period Simulation (EPS)

    Learning Resource Guide for new users of Bentley WaterGEMS and WaterCAD

    WaterGEMS and WaterCAD TechNotes and FAQs

    Hope this helps.


    Regards,

    Yashodhan Joshi

Reply
  • Hi Jay,

    Extended Period Simulation (EPS) type analysis is used when you want to understand the hydraulics of a system over a specified period of time. EPS is basically a series of Steady State runs performed for multiple time steps. When you analyze a model for steady state analysis the hydraulic results obtained are for that particular instance. EPS does this analysis over a period of time.

    When you are viewing the results for an EPS run, you are basically seeing the hydraulics of the system over time.

    In the above image you can see a graph of a junction vs. demand varying over a day (24 hrs). You can see that the time is seen as "4 hrs" and corresponding to that is a demand of 18 L/s. This way you can view the results for all your elements and how are the hydraulics for them over time.

    The multiplier is a factor used to multiply your demand. Typically in water supply system, the demand is not constant for the entire day. The multipliers are specified against each time step so that the proper demand is analyzed for that time step. For example my average demand is 10 L/s but at 6:00 hrs, I require 15 L/s, then we simply specify a factor of 1.5 against 6:00 hrs. Hence the demand at the same junction for 6:00 hrs is 1.5 X 10 = 15 L/s.

    If you are a new user of WaterGEMS, I suggest you go through the Quick Start Lessons available in the Help Section of the software. There are various examples on different features of WaterGEMS which will help you understand its functionality.

    Here are a few articles which are helpful in this regard;

    Run an Extended Period Simulation (EPS)

    Learning Resource Guide for new users of Bentley WaterGEMS and WaterCAD

    WaterGEMS and WaterCAD TechNotes and FAQs

    Hope this helps.


    Regards,

    Yashodhan Joshi

Children
  • Dear Jay,

    The role of the multiplier is very important while running an Extended Period Simulation. Your entire demand of the day is distributed for some hours of time in the entire day (say 24 hours for 24 hours of supply)

    As the supply for each hour varies based on the demand, the demand is multiplied by the respective peak factor.

    For example, you have to eat a single apple in one day every hour. You are much hungry in the morning so your multiplier will be more and you will get a large piece of cut from the apple. You are less hungry during the evening time so the multiplier will be less and you will get a small piece cut from the apple. Likewise, you will finish the entire apple in 24 hours of time.

    Your single apple is the total demand, and your each piece of cut is the supply you are getting as per your demand when multiplied with the peak factor.

    Note:- Just make sure that the sum of your multiplier matches the no, of hours of supply and the average for the same is unity.

  • Please note that a subsequent reply to this thread has been split to a separate thread here: Problems were found during validation


    Regards,

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