Construction of collision model of diatomic molecules (1st report, The MD simulation of molecular collision)

At present, the DSMC method is the best scheme to analyze rarefied gas flows. However, polyatomic inelastic collisions which have complicated energy transfer between translational and internal degree of freedom cannot be analyzed accurately. In this paper, a model for energy exchange between translational and rotational degrees of freedom is constructed using the results of MD simulation. In this 1st report, we describe how to simulate the collision of diatomic molecules by the MD method and the results of the simulation. We find that the energy transfer is distributed without a characteristic relation to the direction and orientation of the rotational vector, and that both the energy transfer and collisional cross section strongly depend on the initial translational and rotational energy.