Abstract: D2Q9 model of lattice Boltzmann equation method was used to simulate the
sedimentation of two circular particles in a bounded two dimension channel. The characteristics of the sedimentation shows some periodicity for the Reynolds number Re chosen, 0.1-20. The larger the Reynolds number, the stronger the interaction between the two particles and the larger the transversal displacements. For large Re the two particles leading alternately; for small Re the initially leading particle will keep its leading position and for moderate Re the initially upper particle will get leading position and keep it. The influence of the initially relative position of the two particles on sedimentation is small. The width of the channel won't change the characteristics of the sedimentation as a whole, but will change the period of the sedimentation. The wider the channel, the longer the period will be.

Key words: lattice-Boltzmann equation, sedimentation, collision, circular particle