[TRNSYS-users] Time Step

[Matt Duffy]

Dear Nicola,

I am not quite sure if I interpretted this correctly across our
Italian-English barrier; however, I will offer some tips about choosing an
appropriate time step. First, a good rule-of-thumb is to keep your
timestep in the units of hours. You can do this either by assigning an
appropriate decimal (i.e. 0.125 hr for 7.5 minutes) or by using a string
like the attached jpeg (i.e. 5/60 for a 5 minute timestep, 1/60 for a 1
minute timestep, 25/3600 for a 25 second timestep, etc.). In another note
about timesteps, please realize that controllers in your simulation will
make a control decision once per timestep. Thus, you would not want to
have a 1 hr timestep if you have a controller in your simulation. Last, if
you are concerned about how low you can bring your timestep, simply
decrease it until you notice the results are uneffected or do not change
much.

Best regards,

Matt Duffy


----- Original Message -----
From: "Nicola Sorbi Unipg" <nicolasorbi at mach.ing.unipg.it>
Sent: Wed, September 23, 2009 5:24
Subject:[TRNSYS-users] Time Step

Dear all,

I have a question: Who the Time Step influences the simulation results?

I have trouble in choosing the correct Time step!!!

Regards





                    Dott. Ing. Nicola Sorbi



          UNIVERSITA' DEGLI STUDI DI PERUGIA

           Dipartimento di Ingegneria Industriale

           Via G. Duranti 1A/4 - 06125 Perugia

           Tel. +39 075/5853930 - Fax. +39 075/5853736

           E-mail nicolasorbi at mach.ing.unipg.it









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