## CONFIGURATION FACTORS FOR RADIATION TRANSFER BETWEEN DIFFUSE SURFACES

* Following from: *Properties of real surfaces

* Leading to: *Net radiation method in radiative transfer

### 1. INTRODUCTION

Configuration factors (also often called shape factors, form factors, view factors, or
angle factors) define the fraction of uniformly distributed radiative energy leaving
diffuse surface *j* that is incident on a second surface *k*. The configuration factor from
a differential area element d*A _{j}* to a second element d

*A*is denoted by d

_{k}*F*. In general, such a factor is given by

_{dj-dk}(1) |

where the quantities on the right-hand side are shown in Fig. 1.

**Figure 1. Defining geometry for configuration factor.**

The notation adopted here is that used in Siegel and Howell (2010). The
differential form d*F* for element-to-element configuration factors is used to maintain
the differential order of the equation to agree with the differential area on the
right-hand side.

Equation (1) can a ...