Collision model for air

Microscopic collision model for nitrogen and oxygen molecules

The dataset contains:

1. CTC results

Files with the results of calculations are presented below as files with names "NNNN_md_distr_XX.csv", where NNNN corresponds to a pair of colliding molecules, XX corresponds to the following parameter P after collision:

List of fields inside a file:

Results of trajectory MD calculations

Post-collision value N2‒N2 O2‒O2 N2‒O2
γ_r Download DownloadDownload
γ_1 Download DownloadDownload
g_x Download DownloadDownload
g_y Download DownloadDownload
g_z Download DownloadDownload

2. Collision model code

The proposed collision model was implemented as a C++ class:

Before use, it is necessary to initialize once the model from the file:

        #include "collisionmodel.h"
        // Model class
	collisionmodel cm;

	// Init model from file

To calculate the post-collision parameters of the colliding molecules, you need to call the function ComputeCollision(...) with the the pre-collision parameters as arguments:

        // Pre-collision values
	double b = ...;
	double er_before = ...;
	double ein_before[2] = {...};

        // Post-collision values
	double er_after, ein_after[2], chi;

        // Compute post-collision parameters
	cm.ComputeCollision(b, er_before, ein_before, &er_after, ein_after, &chi);

Related Publication

Artem Yakunchikov, Vasily Kosyanchuk, Aliya Iuldasheva, Rotational relaxation model for nitrogen and its application in free jet expansion problem // Physics of Fluids 32, 102006 (2020) https://doi.org/10.1063/5.0021704


The research is carried out using the equipment of the shared research facilities of HPC computing resources at Lomonosov Moscow State University and Joint Supercomputer Center of the Russian Academy of Sciences. The research was supported by the Russian Foundation for Basic Research (project № 18-31-20025).