What does collision integral mean?

Collision integral is a physical quantity reflecting the interaction between molecules of matter, which is often used to calculate gas viscosity and gas diffusion coefficient, so it is of great significance to accurately estimate the collision integral value. Collision integral is a complex function of dimensionless temperature t * = t/(ε k- 1), and its calculation accuracy depends on the selected potential energy function model. Lennard-Jones( 12-6) model is the most commonly used potential energy function model, and Lennard-Jones( 12-6) potential energy function comprehensively considers intermolecular repulsion and gravity, which has a strict theoretical basis. Lennard-Jones( 12-6) model can get satisfactory results in solving gas viscosity and gas diffusion coefficient, and it has been widely used in the calculation of collision integral. The calculated value of collision integral has been listed in a table, from which the collision integral value can be found from the dimension-temperature t *.

[1] stone. Using Genetic Programming to Design Correlation Collision Integral [J]. Chemical Engineering, 2008,36 (12): 44-45.