Numerical Determination of Radiative View Factors Using Ray Tracing

A ray-tracing method is presented for numerically determining radiative view factors in complex three-dimensional geometries. This method uses a set of “primitive” shapes to approximate the required geometry together with a Monte Carlo simulation to track the fate of randomized rays leaving each surface. View factors were calculated for an operational fiber drawing furnace using both numerical integration and ray-tracing methods. Calculated view factor profiles were essentially identical above a ray density of 105 per unit area. Run times for the ray-tracing method were considerable longer, although the setup time to describe a new geometry is very short and essentially independent of system complexity.