[TRNSYS-users] small time step problem

[thornton at iyonmail.com]

Quoting Piya Siangsukone <piya.siangsukone at anu.edu.au>:

> I have a problem when I run TRNSYS with type 16 radiation processor
> component using a very small time step (0.1 minute).
> Without type 16 I can run TRNSYS (based on 0.1 minute time interval) with
> no problem.
>
> Are there any hints?

Actually you can run into the problem in Version 16 as well (as I just found
out).  One thing to check is your definition of the time step.  If you are
using the Studio (iisibat) don't set your timestep by changing the units to
minutes and entering 0.1.  Instead use a string variable and define an equation
which is:

TIMESTEP=0.1/60

The unit conversions in the studio will introduce enough round off error to
cause the problems that you are seeing.

Jeff

Jeff Thornton
Thermal Energy System Specialists (TESS)