[Radiance-general] Approximating the gross daylight flux through venetian blinds.

[Santiago Torres]

Hello,
There`s a new paper that is related, but can be accessed online only (as far
as I know):

M. Andersen, M. Rubin, R. Powles, J.-L. Scartezzini, Bi-directional
transmission properties of venetian blinds: experimental assessment compared
to ray-tracing simulations, Solar Energy, In Press.

It discuses mainly the method to measure BRTDs, but not much about the
application to simulations. If somebody has more information about this
research, I would also be interested to know.
On the other hand, to simulate blinds, would it be possible to combine a
BRTD with a linear function that accounts for the slats? I mean, can the
BRTDfunc be dependent on the object coordinates? just an idea, I don`t know
if it makes much sense.

Regards,
Santiago


> -----Original Message-----
> From: radiance-general-bounces at radiance-online.org
> [mailto:radiance-general-bounces at radiance-online.org]On Behalf Of
> Reinhart, Christoph
> Sent: Saturday, October 30, 2004 1:10 AM
> To: 'Radiance general discussion'
> Subject: RE: [Radiance-general] Approximating the gross daylight flux
> through venetian blinds.
>
>
> Greg, I think that it would be REALLY useful for
> daylight-coefficient-based
> daylight simulations if someone (meaning you:)) came up with a
> BRTDFunc for
> blinds. This way one could simulate interior annual illuminance profiles
> with the blinds opened and closed. This is already possible if
> one simulates
> the blinds geometrically in gory detail (genblind), but the
> simulation times
> are horrendous. I assume the calculation time penalty would be less severe
> if one used "BRTDFunc" instead? To my knowledge, mkillum cannot  be used
> with a daylight coefficient approach since mkillum is tied to a
> specific sky
> condition?
>
> Christoph
>