Non-analog momentum deposition estimators for Monte Carlo radiative transfer

Joshua Hykes, North Carolina State University

Analog Monte Carlo momentum deposition estimators in radiative transfer tally the change in momentum at each particle interaction. The analog estimator often produces results with unacceptably high statistical errors. We propose three non-analog estimators that tally the non-zero terms in an integration of the equation of radiative transfer. These three estimators are the absorption, collision, and track-length tallies. One-dimensional numerical results demonstrate improvements of all three non-analog estimators over the analog estimator in nearly all test problems for a wide variety of material properties. The track-length estimator has the best performance, with figure of merit gains of up to 100 times.

Abstract Author(s): Joshua M. Hykes, mentored by Jeffery D. Densmore