Dieter A. Wolf-Gladrow Alfred Wegener Institute for Polar and Marine Research, Postfach 12 01 61 D-27515 Bremerhaven Germany e-mail:
[email protected] Version 1.05 Lattice-Gas Cellular Automata and Lattice Boltzmann Models - An Introduction June 26, 2005 Springer Berlin Heidelberg NewYork Hong Kong London Milan Paris Tokyo Contents 1 Introduction ............................................... -1 1.1 Preface ................................................ 0 1.2 Overview............................................... 2 1.3 The basic idea of lattice-gas cellular automata and lattice Boltzmannmodels ...................................... 5 1.3.1 TheNavier-Stokesequation......................... 5 1.3.2 Thebasicidea.................................... 7 1.3.3 Top-downversusbottom-up........................ 9 1.3.4 LGCAversusmoleculardynamics................... 9 2 Cellular Automata ......................................... 13 2.1 What are cellular automata? . 13 2.2 A short history of cellular automata . 14 2.3 One-dimensional cellular automata . 15 2.3.1 Qualitative characterization of one-dimensional cellular automata . 22 2.4 Two-dimensional cellular automata . 28 2.4.1 Neighborhoodsin2D.............................. 28 2.4.2 Fredkin’s game . 29 2.4.3 ‘Life’ ............................................ 30 2.4.4 CA: what else? Further reading . 34 2.4.5 FromCAtoLGCA................................ 35 VI Contents 3 Lattice-gas cellular automata .............................. 37 3.1 The HPP lattice-gas cellular automata . 37 3.1.1 Modeldescription................................. 37 3.1.2 Implementation of the HPP model: How to code lattice-gas cellular automata? . 42 3.1.3 Initialization...................................... 46 3.1.4 Coarse graining . 48 3.2 The FHP lattice-gas cellular automata . 51 3.2.1 The lattice and the collision rules . 51 3.2.2 MicrodynamicsoftheFHPmodel .................. 57 3.2.3 The Liouville equation . 62 3.2.4 Massandmomentumdensity......................