Application of Monte Carlo techniques to transient thermal modeling of cavity radiometers having diffusespecular surfaces
Abstract
A viable alternative to the net exchange method of radiative analysis which is equally applicable to diffuse and diffusespecular enclosures is presented. It is particularly more advantageous to use than the net exchange method in the case of a transient thermal analysis involving conduction and storage of energy as well as radiative exchange. A new quantity, called the distribution factor is defined which replaces the angle factor and the configuration factor. Once obtained, the array of distribution factors for an ensemble of surface elements which define an enclosure permits the instantaneous net radiative heat fluxes to all of the surfaces to be computed directly in terms of the known surface temperatures at that instant. The formulation of the thermal model is described, as is the determination of distribution factors by application of a Monte Carlo analysis. The results show that when fewer than 10,000 packets are emitted, an unsatisfactory approximation for the distribution factors is obtained, but that 10,000 packets is sufficient.
 Publication:

4th Conference on Atmospheric Radiation
 Pub Date:
 1981
 Bibcode:
 1981atra.conf..181M
 Keywords:

 Diffuse Radiation;
 Monte Carlo Method;
 Radiometers;
 Specular Reflection;
 Surface Temperature;
 Temperature Distribution;
 Cavities;
 Earth Radiation Budget Experiment;
 Spacecraft Instruments;
 Transient Response;
 Spacecraft Instrumentation