Re: [EnergyPlus_Support] AirflowNetwork - "too many iterations" error message

[Lixing Gu <gu@xxxxxxxxxxxx>]

Marzia:

The choice of SURFACE AVERAGE CALCULATION for wind pressure coefficient type 
is only applied to a rectangular building: four orientations only for 
vertical walls. EnergyPlus only provides four boundary conditions and 
associated wind pressure coefficients. Your building has 12 orientations. 
This choice can not be used. You have to use the choice of INPUT, then input 
wind pressure coefficients.

Lixing

----- Original Message ----- 
From: "marziasedino" <marziasedino@xxxxxxxx>
To: <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Wednesday, September 03, 2008 2:45 PM
Subject: [EnergyPlus_Support] AirflowNetwork - "too many iterations" error 
message


>
> Hi all,
>
> I am simulating the airflow in a supertall building with simple
> openings at the bottom and at the top.
> I am using the SURFACE AVERAGE CALCULATION wind pressure coefficient
> type even if the building hasn't got a rectangular shape (but a
> cylinder one) beacuse I do not dispose of the wind specifications
> required for the INPUT option.
>
> I am running an hourly simulation all the year long, but after
> February it crashes showing the following message:
>
>
>
> Severe  ** Too many iterations (SOLVZP) in AirflowNetwork simulation
>   ** Warning ** AirflowNetwork: SOLVER, Changing values for
> initialization flag, Relative airflow convergence, Absolute airflow
> convergence, Convergence acceleration limit or Maximum Iteration
> Number may solve the problem.
>   **   ~~~   **  Occurrence info=INCH'ON - KOR IWEC Data
> WMO#=471120, 04/27 12:20 - 12:30
>   **   ~~~   ** ..Iterations=30000, Max allowed=30000
>   **  Fatal  ** AirflowNetwork: SOLVER, The previous error causes
> termination.
>
>
> I know someone had the same problem with the 1.4 version but I
> couldn' find the solution on the forum (message 7445 "Airflow Network
> through multizones").
>
> can you help me please?
> I submitted the file in the Problem_Submittals folder, its name
> is "airflow supertall"
>
> thanks a lot in advance!
>
> Marzia
>
>
> ------------------------------------
>
> The primary EnergyPlus web site is found at:
> http://www.energyplus.gov
>
> The group web site is:
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>
> Attachments are not allowed -- please post any files to the appropriate 
> folder in the Files area of the Support Web Site.
>
> EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the 
> Documentation link and press the "search" button.
> Yahoo! Groups Links
>
>
>
> 


------------------------------------

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