Aerodynamic coeficient of vents

[iker23]

Hi group!

As evrybody knows when you choose a natural vent to desing a smoke
control instalation for a building, the manufacturer gives us the data
of "aerodynamic coefficient" which represents how much area of the
vent is effective to extract the smoke. My question is:

How can I input this data in FDS? & How can I calculate the
"aerodynamic coefficient that FDS uses?

When I calculate the necessary area for my model I use the EN 12101
standar.

Regards & Thanks!!

[rmcdermo]

Just change the inlet area of your vent to represent the vena
contracta. FDS does not use an "aerodynamic" dynamic coefficient.
Why would it? This is the kind of thing you would use if you did not
have FDS. If the vent is completely submerged in a grid cell, then
you must manually adjust your mass flow or velocity to account for
this.

This question sort of falls in the same category as the friction
factor and drag coefficient question. We are working diligently to
improve FDS models in this area.

Cheers,
R

[Kevin]

As a follow-up to rmcdermo's comment -- you might want to investigate
how the aerodynamic coefficient is determined. If it is based on a
standard test configuration, you might want to model that in FDS with
the same grid resolution you plan to use for your application. This
will tell you how well you are capturing the flow behavior and
potentially what adjustments you might need to make because of limited
grid resolution.

> > Regards & Thanks!!- Hide quoted text -
>
> - Show quoted text -