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RE: [EnergyPlus_Support] Re: AFN How to Simulate Hung-Windows?
Tobias:
I noticed you inputs have two triangle openings. If the detailed opening
object is applied to both openings, the AirflowNetwork model will assume
rectangular openings. In other words, the detailed opening object works in a
rectangular shape.
Bidirectional flows only occur in an opening using the detailed opening
object. Two opening objects may not have one opening with flow-in and the
other with flow-out, since both openings have the same boundary condition. I
don't have a good suggestion to have cross ventilation. As I mentioned in my
previous mail, the model does not support single side ventilation. If you
don't have a small crack on the other side, the program should fail.
Hope this helps.
Lixing
-----Original Message-----
From: EnergyPlus_Support@xxxxxxxxxxxxxxx
[mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of tobiasschulzeoooitu
Sent: Wednesday, October 05, 2011 12:31 PM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Re: AFN How to Simulate Hung-Windows?
Dear Lixing,
if a hung-window is opened, the resulting effective opening area is one
rectangular area and two triangles on the side - so i think for
cross-ventilation (wind-driven) I might use the total area depending on the
angle for the "effective area" model or, if the wind-pressure is strong
enough not to generate any bidirectional flow, also the "detailed opening"
model (Best may be to use a long vertical opening). May be the discharge
coefficient has to be adopted. I am right?
The difficulty with the single sided bidirectional ventilation in
combination with for example a bottom hung-window is that because of the
resulting opening geometry (e.g. small triangular areas at the bottom and
the bigger rectangular area at the top) the neutral pressure plane of that
opening is more at the top and may be only 1/3 of the effective area is used
for inflow (at the triangular areas).
So - to overcome this difficulty may be this neutral plane has to be shifted
according to the geometry and opening angle. But may be there is some way
around - like to use two openings which represent the hung-window. One for
inflow - one for outflow. But this might be difficult to control. I thought
may be you or somebody else in the support group has ideas how to model or
read something about AFN and hung-windows...
Best,
Tobias
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Lixing Gu <gu@...> wrote:
>
> Tobias:
>
> Glad to know you made it work using a small crack at the other side and
> verify results. I think you may use the detailed opening object to
represent
> big windows, if you think the detailed opening model can meet your
> requirements.
>
> What is your definition of cross-ventilation?
>
> Lixing
>
> -----Original Message-----
> From: EnergyPlus_Support@xxxxxxxxxxxxxxx
> [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of
tobiasschulzeoooitu
> Sent: Wednesday, October 05, 2011 11:54 AM
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> Subject: [EnergyPlus_Support] Re: AFN How to Simulate Hung-Windows?
>
> Dear Lixing,
>
> it does, if you chose a "detailed opening" for the bidirectional flow and
as
> a second pseudo opening a very small crack on some other construction than
> the window (only to have two openings - which is necessary). I checked it
> against some simple analytical solutions and it worked out fine.
>
> Any ideas for hung-windows and cross-ventilation?
>
> Tobias
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Lixing Gu <gu@> wrote:
> >
> > Tobias:
> >
> > The AirflowNetwork model does not support single side ventilation.
Please
> > let us know if you find a good network model to simulate two-way flows
at
> a
> > single opening.
> >
> > Hope this helps.
> >
> > Lixing Gu
> >
> > -----Original Message-----
> > From: EnergyPlus_Support@xxxxxxxxxxxxxxx
> > [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of
> tobiasschulzeoooitu
> > Sent: Wednesday, October 05, 2011 11:01 AM
> > To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> > Subject: [EnergyPlus_Support] AFN How to Simulate Hung-Windows?
> >
> > Hello,
> >
> > I couldn't find how to describe Hung-Windows (top/bottom/side) in the
AFN
> -
> > Model. May be the effective Area would be a way for cross ventilation,
but
> > how to deal with bidirectional single sided ventilation? I plan to
> simulate
> > the ventilation rates according to an opening angle of hung windows.
> > Variables i could use (probably together with EMS) are the discharge
> > coefficient, the window hight, the window width and the opening factor.
I
> > think for a controlled, bidirectional flow the detailed opening model
> should
> > be best. Do you have any recommendations how to model or some literature
> > describing the problem?
> >
> > Thank you,
> > Tobias
> >
> >
> >
> >
> >
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>
>
>
> ------------------------------------
>
> Primary EnergyPlus support is found at:
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Attachments are currently allowed but be mindful that not everyone has a
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Yahoo! Groups Links
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Primary EnergyPlus support is found at:
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