view factors

["Joachim Klinner" <joachim.klinner@xxxxxx>]

Hi everyone,

I've got a question regarding 'view factors' used in TYPE19-DETAILED
ZONE (trnsys 14.2). In 'geometry mode 2' view factors from surface i to
surface i+1,..., N are to be entered. What is the mathematical
description of this view factor? Is it the same as following?:

F_ij= Integral_above_A_i   Integral_above_A_j cos(alpha_i)*
cos(alpha_j)*1/r² *dA_i*dA_j

i, j = surface number
A_i, A_j =Area of surface i, j
F_ij = view factor from surface i to surface j
N =  number of surfaces comprising zone
r =  distance between dA_i and dA_j
alpha_i = angle between surface normal of dA_i and vector r
alpha_j=  angle between surface normal of dA_j and vector r

Can anybody help?

Thanks and regards,

******************************************************
Joachim Klinner, Engineer <joachimk@mail.fo.fh-koeln.de>
ILB at  University of Applied  Sciences Cologne
adr.:   Institut für Licht- und Bautechnik an der FH-Köln
        Lustheide 85
        D-51427 Bergisch Gladbach
phone:  0049-(0)2204-204-313
fax:    0049-(0)2204-204-363
******************************************************