Two-dimensional simulation of intermediate-sized bubbles in low viscous liquids using counter diffusion lattice Boltzmann method

•We directly simulate intermediate-sized bubbles in low viscous liquids.•The path instability and shape oscillation can be successfully simulated.•The motion of a pair bubble and bubble swarm is presented.•Bubbles with high-Reynolds-number can be simulated with under-resolved grids.•The counter diffusion multiphase method is feasible for the direct simulation of bubbly flows.