Rain load = Rain*(R1 + R2*Wind velocity)

[james bertram]

Good morning - been searching for information on R1 and R2 to ensure I understand the best and worst-case boundary settings....
R1 seems clear: vertical (wall) = 0, horizontal (roof) = 1, but can't find a description for R2 or the units (s/m) used (is this something to do with how wdr distributes across the facade?)?

[Christian Bludau]

Hello James,

the R1 is used to include the rain without the influence of wind. We use that for roofs for example, as 100% of the rain will a inclinated surface. Thats the reason why with a inclination smaller than 90° R2 is set to zero ("wind off") and R1 is set to 1 ("all of normal rain on surface").

So R1 has no unit, just a factor
and R2 is in s/m, if you multiply it with the windspeed in m/s you again get the unitless factor.

PLease also see the online help of WUFI, topic 61, Dialog: Orientation / Inclination / Height

Christian

[james bertram]

Thank you Christian, I appreciate your support (bit lonely out here in the antipodes!).

[fostertom]

Bit academic - you don't get any rain there do you