Numerical simulation of pollution transport and hydrodynamic characteristics through the river confluence using FLOW 3D

Abstract The current study tried to investigate the hydrodynamic characteristics and pollution mixing dispersion from sub-branch through river confluence using numerical model of Flow3D. A was used with length, width, height (7 × 1 1) m. Also, nested mesh in junction refine modeling result depiction. It observed that if there is a water level difference on both sides junction, will occur much faster, only longitudinal prevail downstream junction. Therefore, it concluded reduce contamination effect networks, main channel should be higher than sub-branch. In flow separation zone, several clockwise vortices were observed, which become weaker by moving towards outer wall channel. most significant velocity vectors also highest contaminant concentration this region. Moreover, vertical distribution showed would at large distances above bed. values turbulent intensity kinetic energy recirculation zone. increase gradient shear layers, required length for complete transverse decreased.