Temporal evolution of scour depth and hydrodynamics around T-shaped spur dikes

This study investigates the temporal evolution of scour depth and hydrodynamics around T-shaped spur dikes. The study includes 12 physical experiments with four different T-shaped spur dike sizes and three distinct velocities of 0.23, 0.28, and 0.34 m/s. Additionally, numerical modeling is performed with four different T-shaped spur dike sizes at velocity of 0.34 m/s. The effects of the densimetric Froude number, dimensionless time, and spur dike length on the scouring process are analyzed using the experimental data. Furthermore, a relationship is proposed to estimate the development of scour depth, and statistical sensitivity analyses are performed to assess the consistency of the proposed relationship with the observed data and identify the most influential parameters in the scouring process. The result of numerical modeling is validated against experimental results with an error margin of less than 7%. The simulated results provide insights into the evolution of local scour and flow field evolution, such as velocity vector fields, streamline patterns, turbulent kinetic energy, turbulence intensity, and Q-criterion. The scour evolution is analyzed for all the cases at 25%, 50%, 75%, and 100% of equilibrium conditions, which reveal the essential features of the scouring dynamics. The study provides insights into the hydrodynamics and scour process and will be useful in the design of T-shaped spur dikes for riverbank protection.