How to set up a demand pattern when flow of once in "x" days is required?

Question

Hi, 
 The water is need to be supplied to the consumers every once in "x" days. Say, here it is considered as once in 5 days. 
 If one has to run the simulation for one week (168 hours), how shall the patterns be setup for the above problem statement? 
 I have tried using "Daily Factors" option in hydraulic pattern by putting multiplier as 1 for Thursday and 0 for all other days. The hourly demand pattern has been set as 1 for 24 hours with time step of 1 hour. But this will enable supply only on Thursday, which becomes once in 7 days!! 
 One thing that was observed after computing the model was that the flow was getting supplied from Friday onwards, that is at the end of Thursday. This does not seem to be correct. 
 Kindly help with this problem of modelling the intermittent supply.

Sushma Choure · Answer

Hello Chetan, 
 The key element while setting yo daily pattern and hourly pattern is setting up correct start time and correct simulation start date in the calculation options. 
 The reason why you see different pattern followed than what mentioned is if you have starting date set to some other day than Monday. 
 E.g. in below screenshots, start day is Saturday, so software will pickup patterns from Saturday from daily pattern. As Saturday has zero daily pattern so for first 24 hours zero demand supplied and as Sunday and Monday have demand multiplier 1.0 so full demand is supplied as per hydraulic pattern supplied in hourly pattern. 
 
 The below wiki explains how to set up hourly, daily patterns correctly, please go through it. 
 How to set separate weekday and weekend patterns

Yashodhan Joshi · Answer

Hello Chetan, You can setup a simple "hourly" pattern in terms of "days". See the snapshot below; Here I have set the multiplier as 1 for Thursday (which would actually be the fourth day starting with Monday). The total duration I have set is for 33 days (792 hours), because at the 32nd day the factor of 1 is again set to Thursday. This way you can achieve the flow at every fourth day. You can also try using controls to set this up but I found you would have to set composite conditions like; IF Time From Start >= 4 days AND Time From Start < 8 days THEN Pipe Status = "Open" ELSE Pipe Status = "Closed" OR IF Time From Start >= 8 days AND Time From Start < 12 days THEN Pipe Status = "Open" ELSE Pipe Status = "Closed" OR IF Time From Start >= 12 days AND Time From Start < 16 days THEN Pipe Status = "Open" ELSE Pipe Status = "Closed" OR .... and so on till the end of simulation. For more details refer the below article on this; Using "Clock Time" and "Time From Start" Controls The easiest way would be to setup the pattern as seen in the snapshot. However, if you do have hourly patterns and not just fixed demands at your nodes then you would have to use controls. Let me know if this helps.