http://www.lbmethod.org/ 2010-09-05T00:37:04+02:00 http://www.lbmethod.org/ http://www.lbmethod.org/lib/images/favicon.ico text/html 2008-02-20T10:31:21+02:00 http://www.lbmethod.org/models:bc?rev=1203499881&do=diff Boundary conditions (BC) are a quite complex problem in lattice Boltzmann (LB) methods. The difficulties arise from the fact that there exists no physical intuition on the behaviour of the velocities distribution function on boundaries. Usually we only have macroscopic information (e.g. no slip BC on walls for fluid flows). We therefore have to translate this macroscopic information on the microscopic distribution functions. There is no unique way of doing this translation and many authors propo… text/html 2008-02-14T23:03:41+02:00 http://www.lbmethod.org/models:lbmodels?rev=1203026621&do=diff Lattice Boltzmann models The most commonly used lattice Boltzmann models are summarized on this page. Be aware though that opinions sometimes differ on how certain models should be classified. The following is a rough guideline which must be taken with a certain flexibility. text/html 2008-03-14T13:24:35+02:00 http://www.lbmethod.org/models:tricks?rev=1205497475&do=diff There are some numerical or algorithmic tricks that one can apply to the LB models in order to improve the accuracy and the performance. We list here some of them that are also used in OpenLB. Equilibrium computation When you compute the BGK equilibrium distribution function, you have to evaluate a function of the form . If ε is too small (when Mach number is too small) then when you numerically evaluate the equilibrium, you will get as a result something of the form ... (for example). Since t…