New method for estimation of velocity distribution in the river based on single point of velocity measurement

Investigating the velocity distribution within open channels is crucial for both hydraulic engineering and research due to its extensive practical uses. This study introduces an improved two-dimensional flow velocity model based on the simplified Reynolds-averaged Navier-Stokes equations for predicting velocity distribution and estimating discharge in open channels. The finite volume method, integrated with an unstructured triangular mesh, is employed for the numerical solution of the equations. The approach to calculating turbulent viscosity significantly affects the model's precision. In this case, the turbulent eddy viscosity is determined using the mixing-length theory. The eddy viscosity in open channels is ascertained by measuring velocity at a central point in the river's cross-section, which then informs the computation of eddy viscosity and velocity distribution throughout the channel. Various experimental scenarios, including different channel cross-sections and roughness conditions, were examined to validate the model. The findings confirm that the model reliably predicts velocity distribution and river discharge.