Solid Particle Settlement in Open-Channel Flow

A random walk is formulated to describe the settlement of solid particles in open-channel flows. Both uniform and mixed-size sediment particles are tested. Results from simulations indicate that the probability density function of the settling length can be a lognormal distribution. The mean settling length can be estimated by the ratio of the unit-width discharge to the fall velocity of particles. The coefficient of variation is determined to be a power function of the ratio between flow shear velocity and fall velocity of solid particles. The simulation results are generally in agreement with measured data. The procedure for the design of settling basins is presented.