Improved One-Dimensional Velocity Deformation Model for Unsteady Flows
Authors :- M Dabhi, M Langhi
Publication :- Hydraulics and Fluid Mechanics, Volume 2: Select Proceedings of HYDRO 2023, Springer 2024.
The effect of unsteadiness during the flood events plays an important role, causing the flow characteristics vary during the rising and falling stages of the flood flow. It is crucial to examine the streamwise velocity distribution to comprehend the hydrodynamic properties of unsteady non-uniform flows. One-dimensional depth-averaged models conveniently resolve the problems in the rivers due to its small computational requirements. The underlying principle of such models is to consider a velocity distribution along the depth and determine the bed shear stress by applying the momentum equation. Using similar approach, in the present study, an improved velocity deformation model is proposed to study the characteristics of unsteady non-uniform flows in open channels. The proposed model is based on the idea that the vertical profile of the streamwise velocity can be expressed as a power series, with the coefficients of the series are determined by using the unsteady equation of motion. The accuracy of the one-dimensional improved velocity deformation model was verified by comparing the simulated results with the existing experimental data. The comparisons of numerical results showed that the model produced a reasonably good agreement with the observed data. The proposed model offers an efficient and accurate way to simulate the unsteady non-uniform flow behaviors in open channels.