A new model for virtual radiometers

There exists a general need to compare radiative fluxes from experimental radiometers with fluxes computed in Thermal/Fluid simulations. Unfortunately, typical numerical simulation suites lack the ability to predict fluxes to objects with small view angles thus preventing validation of simulation results. A new model has been developed that allows users to specify arbitrary view angles, orientations, and locations of multiple radiometers, and receive as the output, high-accuracy radiative fluxes to these radiometers. This virtual radiometer model incorporates a reverse monte-carlo ray tracing algorithm adapted to meet these user specifications and runs on both unstructured and structured meshes. Verification testing of the model demonstrated the expected order of convergence. Validation testing showed good agreement between calculated fluxes from the model and measured fluxes from radiometers used in propellant fires. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract.