[TRNSYS-users] Problem with View-Factor Matrix and detailed radiation mode

Marion Hiller hiller at transsolar.com
Tue Nov 22 00:48:37 PST 2011


Dear Damien,

 

I don’t know what you did, but the geometric part of you’re the surface
wasn’t there anymore.

This happens when you set the geomode to manual.

Well, I recreated the data and placed it into your B17 file and the
amtrices are created as expected. 

 

However, have in mind that turning on the detailed radiation mode for
longwave radiation slows down your simulation significantly.

I recommend to setup everything and make test runs with the standard
mode for longwave radiation. 

When everything works fine then turn it on.

 

Marion

 

Dipl.-Ing. Marion Hiller 
TRANSSOLAR: KlimaEngineering - Technologien für energieeffizientes Bauen
und Nutzerkomfort in Gebäude 
Munich - New York - Stuttgart + 49.711.67976.0 

Transsolar Energietechnik GmbH, Curiestrasse 2, 70563 Stuttgart 
Amtsgericht Stuttgart - HRB 23347, Steuernummer 99073/00911, USt-IdNr.:
DE152272639

Geschäftsführer: Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer,
Dipl.Phys. Stefan Holst, Prof. Dipl.-Ing. Bleicher 

 

 

  _____  

Von: Damien Gondre [mailto:damien.gondre at insa-lyon.fr] 
Gesendet: Montag, 21. November 2011 11:35
An: trnsys-users at cae.wisc.edu
Betreff: [TRNSYS-users] Problem with View-Factor Matrix and detailed
radiation mode

 

 

Dear Trnsys-Users,

 

I try to model a double-skin facade on Trnsys, using Trnsys3d, the
multiple nodes feature and Contam.

 

The double-skin facade is a 1.2-meter wide and 2.8-meter high zone that
is split vertically in four 0.7-meter high zones separated by virtual
surfaces that are not imported in TRNBuild. I have imported the SketchUp
model into Trnbuild. I have moved the nodes of the double-skin façade
into one single zone. 

 

I have set the radiation modes to “detailed model” (for beam, diffuse
and longwave radiation) only in zones where I want to perform detailed
radiation calculation. So I think I’m all set to generate the
view-factor matrix file but TRNBuild doesn’t calculate it: I don’t get
any error when I click on Generate < Generate View-Factor Matrix but
there is no matrices in the *.vfm file that is generated (only zones ID
numbers and names, and a 0 below each line – see attached file: it looks
like detailed radiation mode is not selected in any zone).

 

I use Trnsys 17.00.0019, Trnsys3d version 1.0.5.2 and TRNBuild 2.0.167.

 

I’m sure I’ve done something wrong but I can’t find my mistake in the
user-guide or in the trnsys-users archives. 

Does someone know how I could generate proper view-factor matrices?

 
I’m also facing the same problem with the shading matrix. I defined a
shading group in Trnsys3d but it seems like TRNBuild ignore it when
calculating the *.shm file: “No window is shaded. Therefore no shading
matrix file *.SHM is written!” (even if I’m pretty sure several windows
are shaded).
 
 
I tried to compare my *.bui file to the *.bui file in the 3D_Building
example folder. I noticed that there is a missing part in my *.b17 file
in the section _EXTENSION_BuildingGeometry _. Indeed the
_EXTENSION_BuildingGeometry_END_ statement comes right after the
description of the vertices. There is no part with description of
vertices used by each wall of each zone like in the example file:
zone EG_GB
wall 1 1 2 3 4
wall 2 5 6 7 8
[…]
 
I also noticed that when I try to update the Trnsys3d file to go back in
SketchUp, description of surfaces comes with description of zones only
for virtual surfaces so that when I open the updated Trnsys3d file in
SketchUp, only virtual surfaces are drawn. 
I think these two comments might help solving the problem. 

 

 

Any idea would help,

Thank you,

 

Damien.

 

 

Attached: *.idf, *_b17.idf, *.b17, *.vfm, *_shd.log, *_updated.idf


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