Hi,
I am trying to run a hydraulic model for 48 hrs. in EPS mode in WaterGEMS. I could able to run the model for 24 hrs. Now when I want to extend the run for 48 hrs. what is the best (efficient) method to do the same.
Thanks in Advance.
To change the calculation hours for the EPS run, please go to Analysis>calculation options>EPS solver>base>properties>calculation times>duration>change it to 48 hours.
Hope this helps to you.
Regards
Sushma.
Regards,
Sushma Choure
Bentley Technical Suppport
Hi, I tried this but this is not sufficient. Do we have to change valve controls, demand pattern , etc.?
Hello Dr. PK,
Let me guess a few things and see if I answered your question.
It sounds like the model is running well for 24 hours and now you like to run for longer duration like a 2 days or may be a week or may be a month+ if you are doing Water Quality.
To define patterns, you can enter patterns for certain hours, like 24, 48, then you can also define patterns for different weeks as well as as months. So, if you have historic data then you can create pattern for the duration that you need. Now, if you don't have the data for the entire simulation then it will start repeating. So, for a duration of 3 days, and a pattern of 24 hours, you will see the software will start repeating the same pattern on 24+ hours.
Now, if you want the values or pumps to change their status because of system hydraulics, such as tank is running low, then you want to add a logic to turn the pump on/off based on hydraulics like Tank Level. Same way if valve change their status based on hydraulics and/or time from the simulation has started, you can create such logic too. This can be done from Components > Controls. For more on controls please see:http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/2567.creating-controls-conditions-actions-and-control-sets-tn.aspx
Now, if above is not the answer you were looking for then could you please add details towards your expectation on "what is the best (efficient) method to do the same".
Thanks,
Hi Akshaya:
Thanks for your detailed answer. You have guessed correctly that I want to run the model for 2 days, however only for hydraulics and not for water quality. What I want to see is the percent full curve of the tanks for 48 hrs (which will be replication of curve for 24 hrs).
As I have mentioned in my query I have successfully applied all the controls for 24 hrs. Now, say if for one valve there is control for 16 hrs in 24 hrs run, should I have to repeat the same control once again with extended time as per 48 hrs. format for next 48 hrs run. OR is there any in built function in WaterGEMS by just selecting that model will take all the controls for 24 hrs (which are not going to change for any no. of days of runs) and show the results for 48 hrs.
About demand pattern you already replied in above email that if I don't have data for 48 hrs then model will by default repeat the 24 hrs pattern (in my case my demand pattern for 24 hrs is fixed and I just want to repeat it once again for 48 hrs run which model will do by default). Same thing should be possible for valve and pump controls. This is what I mean best (or efficient) way.
Thanks again.
Controls with conditions based on hydraulic parameters (e.g., tank level) do not need any alteration. Controls based on time depend on whether they are based on simulation time (time from start [of the analysis]) or clock time. Clock time controls have the advantage that they repeat, so this would be the type of control that you would use if you wanted it to apply at the same times every day for simulations longer than 24 hours.
Depending on your demand variation (and the variation of other patterns) in the second and subsequent days you may need to tweak your controls for the system to operate properly (some controls might not handle different hydraulic extremes as well as they appeared to in the first 24 hours, for example).
Using 24 hour patterns and clock based (and hydraulic condition based) controls is the most expedient way to running simulations that last longer than 24 hours.
Note that when running an EPS run the Simulation Start Date and Start Time are important settings in the calculation options. These settings control how clock time based controls work and also how the daily and monthly multipliers for patterns work.
Wayne Hartell
Answer Verified By: Dr. PK
Hi Dr. PK,
As Wayne suggested, you could use the Time based control to trigger the Control at a particular time. I, personally though, am less fan of Time Based control as no matter what goes in the system it will trigger. The only situation I use Time Based control is when Operators in the field have done manual override. Let's say your system works very well in general but because of some circumstance, operator will override the logic in the SCADA and will change the status of some element. Now, at whatever time this happened, I represent this by creating a Time based Control.
I like to model based on SCADA logic and most of the time SCADA logic are based on hydraulics and sometime they are tied with "Clock Time" also. Let's say you have a logic of "If Tank-1 Level <= 4 PMP -1 Status = ON". Now, Tank-1 Level reaches 4 or below, it will turn on the PMP-1. Such types of control are totally independent of simulation duration and will trigger as many times as needed.
So, depending on situations you may want to pick what type of control works the best.
To give an example of what Wayne and Akshaya mentioned, take a look at the Example1.wtg file included with the program. There are controls to turn a pump on and off based on the elevation of a tank. If you extend the duration, those controls continue to operate, as they are based on model conditions irrespective of time.
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Thanks to all for inputs. I have a other difficulty. The client I face here in India most of them do not understand EPS. They want to see results based on pumping schedule and valve setting. Hence, although your suggestion of giving settings to pumps based on Tank level is good but I fear my client will understand it. Since, in reality in India we run pump on continuous basis say for 16-20 hrs. Hence, it is expected to show pump is operating in actual time scale and tanks are giving exact mass curve as per the design.
Thanks once again.