A parallel molecular dynamics simulation of flow around two micro circular cylinders in series

Based on spatial decomposition algorithm, a parallel molecular dynamics simulation was carried out to investigate the behaviors of flow around two microscale circular cylinders in series. The results indicate that there are three basic flow patterns at different cylinder spacings. When L^*=D^* < 1:1, the flow behavior is similar to the features of flow around a circular cylinder. When 1:1 < L^*=D^* < 3:5, the periodic shedding vortices are captured in the wake of downstream cylinder. Simultaneously, two vortices alternately adhere to the downstream cylinder, the size of which increases with the cylinder spacings. When L^*=D^* > 3:5, the shedding vortices are observed in the wakes of two cylinders. The simulation results demonstrate that the critical cylinder spacing is smaller in microscale as compared with that in macroscale. Also, Strouhal numbers at different cylinder spacings were numerically investigated.