ABSTRACT
This chapter examines a number of problems and calculate energy-transfer rates. The view factor is a geometry term for a system in which two surfaces exchange energy by radiation. The crossed-string method is a useful alternative method for determining the view factor for two-dimensional systems. The chapter considers an enclosure consisting of surfaces that behave ideally. Each surface is maintained at a constant temperature. If the isothermal condition cannot be met by a surface, then that surface can be subdivided into a number of smaller surfaces, each at a different but constant temperature. For a gray surface that is diffuse, emissivity and absorptivity are independent of viewing angle and of wavelength. In an effort to ease the task of generating equations for the problem of heat transfer in an enclosure, an electrical analogy has been formulated.
