You do need to be careful with the factors. For structural loads, more important buildings have larger multipliers. Energy models are nowhere the structural loads, so the basic shape coefficients should work.
Sent from my iPhone
Sent from my iPhone
On Sep 10, 2014, at 6:36 AM, "Jean Marais jeannieboef@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
Interesting...thanks.asce7-2002 p72
Wind forces shall be applied in the directions resulting in maximum member forces
and reactions. For towers with square cross-sections, wind forces shall be
multiplied by the following factor when the wind is directed along a tower
diagonal:
1 + 0.75 E, but not > 1.2
E : ratio of solid area to gross area of one tower face for the segment under
consideration.
2014-09-09 18:30 GMT+02:00 'Edward G. Lyon' eglyon@xxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx>:
ASCE 7 has structural wind coefficient data for other shapes. You can probably get some better values there.
Sent from my iPhone
On Sep 9, 2014, at 10:36 AM, "michele.rossi@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
I have already thought the algorithm that Airflow Network uses to calculate this was based on rectangular buildings with flat roofs. But, I want to check it.
I totally agree with you, CFD is the best tool to find the WPCs accurately for all geometries types. But, I will search another simple ones ou some databases to adjust these WPCs and consequently improve the simulation results.
Thank you very much for your help!
---In EnergyPlus_Support@xxxxxxxxxxxxxxx, <jeannieboef@...> wrote :
You can use it on a banana shaped building...the algorithm is based on corrilations from rectangular buildings with flat roofs and within certain aspect ratio limits, but it can be applied to anything, only that the accuracy is likely to diminish more the further away you are from the corrilation data set.
Use it and then adjust those surfaces where it would not apply well manually, such as inner courtyards.
Else, google some other tools that you can use to find the WPCs...CFD is the best and can handle all geometries accurately.
Mit freundlichen Grüßen- Sent from my iPhone (excuse the brevity)
i. A.Jean Maraisb.i.g. bechtoldTel. +49 30 6706662-23
On 05.09.2014, at 18:41, "michele.rossi@... [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
Hello everyone,
I have a doubt about the Wind pressure coefficients (WPC) in the
Airflow Network group in EnergyPlus (natural ventilation modeling).
Can I use the option Surface Average Calculation for the WPCs if the
building has a rectangular plan with pitched roof (see the attached file)?
The I/O Reference Manual does not explain anything about the roof. It
only mentions that the building must be rectangular.
Thank you very much,
Michele Rossi.
<geometry.png>
__._,_.___
Posted by: "Edward G. Lyon" <EGLyon@xxxxxxx>
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
__,_._,___