Investigation of Thermal Conductivity in High-Temperature Nitrogen Using the DSMC Method

Abstract

The Direct Simulation Monte Carlo (DSMC) method is investigated with regard to its ability to represent transport processes in high temperature simple flows and in particular in an idealized Couette‐type flow. Nitrogen is the test gas, with heat transport coefficient to a temperature of 10,000 K being evaluated, assuming that the species may be represented in terms of either the variable hard sphere (VHS) or the variable soft sphere (VSS) molecular models. These DSMC coefficients are then compared to available analytical studies. It is found that for energy fluxes the accuracy derived from the current standard formulation of DSMC is limited to 3,000 K. This limit corresponds to the start of high chemical activity in the flow. Investigation of recombination processes within the framework of Bird’s DSMC formulation reveals that detailed balance is not maintained, and that this may be the cause of poor heat flux representation at high temperatures. It appears that a revised methodology is required to represe...