Allocating Radiant Interchange Factors with Corner Node Modeling

Placing the thermal nodes at the corners of the radiation surfaces results in greater thermal-model accuracy for a given number of nodes, as compared to the more common practice of placing the thermal nodes at the center of the radiation surfaces. Placing the thermal nodes at the corners does, however, add complications in computing radiant interchange factors. In this paper the accuracy of subdividing elements into radiation sub-elements is compared to the accuracy of allocating elemental radiation couplings to the corner nodes. The comparison shows that, for a given number of nodes, the two methods have nearly the same accuracy, provided good modeling practice is followed in both cases.