Three-dimensional numerical study of continuous gravity current in a curved channel

Understanding the dynamics of gravity currents in curved channels is essential for evaluating and mitigating environmental impacts, designing efficient coastal protection measures and predicting sediment transport patterns. This study focuses on the three-dimensional numerical study of continuous gravity current in a curved channel using the Unsteady Reynolds Averaged Navier–Stokes (URANS) equations by the OpenFOAM code. The numerical model was validated against various experimental data from the literature. Multiple simulations were conducted to investigate the effect of the bend radius on the flow structure. The findings revealed that the advance velocity of gravity current exhibits a consistent slope when the radius of curvature is altered. The flow concentration is equal at the initial section of the channel on the inner and outer banks until the middle of the curve. Then the outer bank concentration increased due to the centrifugal force at the flow front. At the end of the bend, as the radius decreases, the front height rises and the flow tends to the outer bank. Maximum velocities in the flow body and head occur on the outer bank. Smaller radii produce higher longitudinal and transverse velocities, strengthening secondary flow.