We present guidelines to estimate the effect of electrostatic repulsion in sedimenting dilute particle suspensions. Our results are based on combined Langevin dynamics and lattice Boltzmann simulations for a range of particle radii, Debye lengths and particle concentrations. They show a simple relationship between the slope of the concentration-dependent sedimentation velocity and the range of the electrostatic repulsion normalized by the average particle-particle distance. When → 0, the particles are too far away from each other to interact electrostatically and = 6.55 as predicted by the theory of Batchelor. As increases, likewise increases as if the particle radius increased in proportion to up to a maximum around = 0.4. Over the range = 0.4-1, relaxes exponentially to a concentration-dependent constant consistent with known results for ordered particle distributions. Meanwhile the radial distribution function transitions from a disordered gas-like to a liquid-like form. Power law fits to the concentration-dependent sedimentation velocity similarly yield a simple master curve for the exponent as a function of , with a step-like transition from 1 to 1/3 centered around = 0.6.
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