Bhatnagar-Gross-Krook

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The Bhatnagar-Gross-Krook (abbreviated BGK) term refers to a collision operator used in the Boltzmann Equation and in the Lattice Boltzmann method, a Computational fluid dynamics technique. It is given by the following formula:

$\Omega_i=-\tau^{-1}(n_i-n_i^{EQ})$

where $n_i^{EQ}$ is a local equilibrium value for the population of particles in the direction of link $\mathbf{e}_i$ The term $τ$ is a relaxation time, and related to the viscosity.

The operator is named after Prabhu Lal Bhatnagar, E. P. Gross, and Max Krook, the three scientists who introduced it in a paper in Physical Review in 1954.^[1]

[edit] References

^ P. L. Bhatnagar, E. P. Gross, and M. Krook, "A Model for Collision Processes in Gases. I. Small Amplitude Processes in Charged and Neutral One-Component Systems", Phys. Rev. 94, 511-525 (1954).

Sauro Succi, The Lattice Boltzmann Equation for Fluid Dynamics and Beyond, Oxford University Press, 2001