Determination of view factors by contour integral technique

This paper presents the application of contour integral technique to derive the diffuse radiation view factor expressions (analytical) for elements of nuclear reactor fuel bundle. The cases considered are: (i) view factor between two cylindrical rods of equal diameter and finite length, (ii) view factor between two cylindrical rods with interference by another rod and (iii) view factor between a cylindrical rod and a non-concentric cylindrical enclosure. The contour integral method is significantly more accurate than the area-integration method. The view factor results based on the analytical expressions derived for these finite length geometries are compared with that of the exact expressions available in the literature for infinite length. It is observed that the use of infinite length approximations in finite length cases can lead to significant errors.