Bhatnagar–Gross–Krook operator

The Bhatnagar–Gross–Krook operator (abbreviated BGK operator) 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: The Bhatnagar–Gross–Krook operator (abbreviated BGK operator) 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: where n i E Q {displaystyle n_{i}^{EQ}} is a local equilibrium value for the population of particles in the direction of link e i {displaystyle mathbf {e} _{i}} The term τ {displaystyle au } is a relaxation time, and related to the viscosity. The operator is named after Prabhu L. Bhatnagar, Eugene P. Gross, and Max Krook, the three scientists who introduced it in a paper in Physical Review in 1954.