Accurate Determination of View Factors in Axisymmetric Enclosures with Shadowing Bodies Inside

A method is presented for calculating view factors accurately in a general enclosure with shadowing objects present inside, in which the surfaces are either axisymmetric bodies of revolution or planar, which has application in the thermal analysis of spacecraft systems. The view factor from an infinitesimally small ring element to a small band on the enclosure is evaluated by application of the contour integration method accounting for the shadowing effect, followed by numerical integration over finite lengths and decomposition rule. The solution of many practical thermal radiation problems in enclosures requires the knowledge of the view factors for a conical enclosure inside which a coaxial cylinder is present. An analytical expression for the view factor from an infinitesimally small ring element on the cone to the end disk is presented. The view factors from the lateral surface of the cone to the end disk are presented in graphical form for a representative case, which is not available in the literature. The preceding technique is applied to a sample enclosure to bring out the shadowing effect, and the results show an accuracy of up to six significant digits in the computed view factors