Fig. 2.
Simulated dynamics of an E. coli-like force dipole swimmer near a wall. (A) Deterministic swimming trajectories towards a wall at y = 0, numerically simulated from Eqs. 2 and 3, where u, ω, and E are due to the hydrodynamic image system. Simulations used a time step Δt = 10-5 s and the experimentally determined parameters A = 31.8 μm3/s, V0 = 22 μm/s and Γ = 0.88 for the force dipole swimmer. The initial distance is chosen such that the swimmer would reach the wall after 1 s if hydrodynamic interactions were not present. (B) Incidence angle θ0 vs. collision angle θhit with the wall for the trajectories in A, using the same symbols and colors. The dotted line indicates θhit = θ0. Both panels illustrate that hydrodynamic long-range interactions can be regarded as small perturbations for typical wall scattering events of E. coli.