smoothed particle hydrodynamics method for three-dimensional open channel flow simulations

To date, the smoothed particle hydrodynamics (sph) method has been successfully applied to reproduce the hydrodynamics behind three-dimensional flow-structure interactions. however, as soon as the effect of flow resistance becomes significant, the results obtained are not consistent with observations. this is the case for open channel flows (ocf), in which the water surface is largely influenced by the boundary friction. the roughness generated by the current boundary condition methodologies is solely numerical and cannot be associated to physical values of friction. in light of this challenge, the authors present a novel formulation for the friction boundary condition. the new implementation includes an additional shear stress at the boundaries to reproduce roughness effects, allowing for the adequate three-dimensional simulation of open channel flows using the sph method. finally, in order to reduce the high computational cost, typical of the lagrangian models, without interfering in the representativeness of the sph simulations, a criterion to define the adequate fluid particle size is proposed.