Hydrodynamic interaction between two nearby swimming micromachines

Numerical results for two nearby swimming micromachines, obtained by the boundary element method (BEM), are reported in this paper. Two neighbouring configurations, side by side and in tandem, are considered and the translational and rotational velocities together with the force exerted on the micromachines are given. It is demonstrated that, for both configurations, the approximate reflection method gives comparable results to the full solutions. In the side by side configuration, hydrodynamic interaction is significant when the separation distance is less than about 1.5 of the total length of the machine. A propulsion advantage in the tandem configuration is found, where the leading machine acquires a higher velocity and the results obtained by the reflection method agree well with the full BEM solution.