Transient Condensation of Vapor Using a Direct Simulation Monte Carlo Method

Abstract

Vapor is produced from the ICF event as the x-ray energy is deposited at the first wall of the reactor. This vapor must condense back onto the first wall in a timely fashion (<< 1 s) to establish the necessary conditions for beam propagation and the next ICF event. Transient condensation of vapor is studied on the basis of the Boltzmann equation using a direct simulation Monte Carlo Method. The method describes the molecular behavior of continuum mechanics transition flows in a way consistent with the Boltzmann equation. The thermal resistance of the condensed film is included in the flow representation using a laminar Nusselt analysis to determine the interface temperature of the condensed film. The condensate mass flux in a quasi-steady state is computed and compared with a number of analytical models and experimental data. The results are consistent qualitatively with the experimental data of mercury condensation on a vertical plate.