[TRNSYS-users] TRNFLOW convergence problems

[Marion Hiller]

Dear Francisco,
 
yes, if a window is closed the parameters "for closed opening"  do
apply. 
However, no flow occurs, when the window is horizontal and the zone has
one window only.
The reason for this is that all cracks are at the same height and a
crack has a one directional flow only.
 
For a vertical window the cracks are placed in different heights and a
flow may occur
 
Concerning the convergence problems. I assume a few not converged time
steps don't influence your results of yearly simulation significantly.
However, I would recommend to always check whether high flows are
realistic.
 
Best regards,
 
Marion
 
 
 
 
Dipl.-Ing. Marion Hiller 
TRANSSOLAR Energietechnik GmbH 
Munich - New York - Stuttgart + 49.711.67976.0 

KlimaEngineering- Technologien für energieeffizientes Bauen und
Nutzerkomfort in Gebäuden 
Transsolar Energietechnik GmbH, Curiestrasse 2, 70563 Stuttgart /
Amtsgericht Stuttgart - HRB 23347 / USt-IdNr.: 99073/00911 
Geschäftsführer: Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer,
Dipl.Phys. Stefan Holst 

 


  _____  

Von: frodriguezpc at labein.es [mailto:frodriguezpc at labein.es] 
Gesendet: Mittwoch, 22. September 2010 14:25
An: trnsys-users at cae.wisc.edu
Betreff: Re: [TRNSYS-users] TRNFLOW convergence problems




Dear Marion, 

many thanks for your answer. You are right, this morning I run a shorter
simulation and saw the problem was related to a sudden increase of
airflow caused by a window opening schedule. I run another simulation
with closed windows and it converged, but I realised I have no flow from
infiltration. I thought this was provided by the "for closed opening"
parameters in the Large Opening Type Manager. Any suggestion about that?


Also, I modified my window schedule by increasing by 0.02 the opening
factor each minute and using a short (0.0125) timestep. My simulation
does not stop, but I still get some convergence problems, probably due
to very large flows in the kitchen, which also has  stack ventilation...
Could some unrealistick stack parameter be the cause? 

Best regards, 

Francisco Rodríguez Pérez-Curiel

TECNALIA-Construcción
Parque Tecnológico, Edificio 700. E-48160 Derio (Bizkaia) (SPAIN)
Tel. +34 94 607 33 00,  Fax. +34 94 607 33 49
francisco.rodriguez at tecnalia.com,
www.tecnalia.com

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