3D Direct Simulation Monte Carlo Modelling of the Inner Gas Coma of Comet 67P/ Churyumov-Gerasimenko: A Parameter Study

Abstract

Direct Simulation Monte Carlo (DSMC) is a very powerful numerical method to study rarefied gas flows such as cometary comae and has been used by several authors over the past decade to study cometary outflow. The drawback with 3D DSMC is that it is computationally highly intensive. This implies that investigation of parameter space can be time consuming. For the target of ESA’s Rosetta mission, Comet 67P/Churyumov-Gerasimenko, we have identified to what extent modification of several parameters influence the 3D flow and gas temperature fields and established the reliability of inferences about the initial conditions from in situ and remote sensing measurements. A large number of DSMC runs have been completed with varying input parameters. In this work we present the models and simulation results and conclude on the sensitivity of solutions to certain inputs.