IMPLEMENTATION OF FINITE-DIFFERENCE LATTICE BOLTZMANN METHOD ON GENERAL BODY-FITTED CURVILINEAR COORDINATES

摘要

A finite-difference lattice Boltzmann (LB) algorithm is described on general body-fitted coordinate systems. An alternative treatment for the implicit collision term of the Boltzmann-Bhatnagar-Gross-Krook equation is used, which completely removes the implicitness of the numerical scheme through using the characteristic of collision invariants. LB simulations are carried out for a two-dimensional supersonic viscous flow past a circular cylinder and the natural convection heat transfer in a circular enclosure with an inner hexagonal cylinder for the first time. The pressure coefficient distribution along the surface of the circular cylinder and the Nusselt number in the natural convection obtained from the simulations agree well with previous experimental measurements and/or classical computational fluid dynamics simulations. Comparisons of detailed flow patterns with other studies are also satisfactory.