[TRNSYS-users] TRNBuild Error

[Dimitris Anastaselos]

Hi all!!
I would like to model very thick walls. In the case I am working I have 
walls around 6m! For this case, TRNSYS (i.e. TRNBuild) cannot calculate 
the transfer coefficients. I have created new walls with 40cm thickness 
and keeping the U-value constant by changing the thermal conductivity.

When I save the project, the following message is shown:

Error creating the wall transfer function coefficient:

Stability criteria not fullfield

Check layer definition (thickness, ratio of conductivity/density)

Please check the INF-file for further information

 

When I check the INF-file the same message is shown: Stability criteria 
not fullfield

 

I have changed the TIMEBASE from 1 to 2 but the problem still remained.

The same was when I set TIMEBASE=3 or 4 or 5 or 6. Only when the 
TIMEBASE is 7 the problem is solved but then the following message is shown:

* *

Error creating the wall transfet function coefficients:

Unable to find a root after indication that a root exists.

Maybe the timebase is too small.

Please, check the INF-file for further information

* *

If I set the TIMEBASE around 100 the above message still remain.

 

What can I do to work around this problem?

-- 
Anastaselos Dimitris
Dipl. Mechanical Engineer
Laboratory of Heat Transfer and
Environmental Engineering
Aristotle University Thessaloniki
Box 483 54124 Thessaloniki, GREECE
Tel: + 30 2310 996048
Fax: + 30 2310 996012
e-mail: jimanas at aix.meng.auth.gr
URL: http://aix.meng.auth.gr