[TRNSYS-users] whole number of simulation start time

David BRADLEY d.bradley at tess-inc.com
Mon Jun 25 13:14:08 PDT 2012


Simon,
   You can start a simulation at non whole numbers but in this case you 
have to be very careful about the difference in output devices between 
"relative time" and "absolute time" Many printing and integrating 
devices give you a choice. If you choose relative time and integrate 
hourly, you will get results that are in one hour intervals starting at 
whatever simulation start time you choose: time = 1.1, 2.1, 3.1, 4.1, 
... If, on the other hand, you choose absolute time and integrate hourly 
then the first integration period won't be a full hour. Your intervals 
will be time = 1.1, 2, 3, 4, ...

And of course your simulation start time must be an integer multiple of 
your timestep. You cannot, for example, have a timestep of 1 hour and a 
start time of 1.1.

Regards,
  David





On 6/25/2012 03:00, Simon Binnemans wrote:
>
> Dear Trnsys user,
>
> When I start a simulation and I do not set the simulation start time 
> to a whole number (not hour 1 but hour 1.1 for example) I get very 
> strange simulation results.
>
> Attached I did a basic simulation where you can see the problem by 
> comparing the simulation results with a start time of 0 hour and a 
> start time of 0.1 hour for example.
>
> Does anyone know if it is always necessary to set the simulation start 
> hour to a whole number?
>
> Thank you for your help,
>
> Simon Binnemans
>
>
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
> https://mailman.cae.wisc.edu/listinfo/trnsys-users

-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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