Hooked-head spur dikes are a specialized type of spur dike, where their geometry significantly influences flow diversion, sediment transport, and bank protection. This study establishes a three-dimensional numerical model utilizing the renormalization group (RNG) k-ε turbulence closure and the volume of fluid (VOF) method to explore the effects of hook angle (90°, 120°, and 150°) and hook-length ratio (L/D = 1/2, 1/3, and 1/4) on the flow structure surrounding a hooked-head spur dike. The study comprises nine simulation cases, and the distributions of mainstream velocity and turbulent kinetic energy (TKE) are analyzed. The results demonstrate that a hook angle of 120° yields the greatest increase in the mean dimensionless mainstream velocity (V*), corresponding to enhancements of 4.26% and 9.09% relative to the angles of 90° and 150°, respectively. When the hook angle is fixed at 120°, increasing the hook length enhances the mainstream velocity; specifically, at L/D = 1/2, the mean V* increases by 10.58% and 14.64% compared to at L/D = 1/3 and 1/4, respectively. Meanwhile, the TKE in the downstream recirculation zone decreases as either the hook angle or the hook length increases. At a hook angle of 90°, the mean dimensionless TKE (E*) is 8.80% and 10.65% higher than at 120° and 150°, respectively. For a fixed hook angle of 120°, the mean E* at L/D = 1/2 decreases by 3.46% and 9.35% compared to at L/D = 1/3 and 1/4, respectively. In summary, the appropriate selection of hook angle and hook length can effectively guide flow toward the channel center, increase conveyance capacity, and enhance hydraulic performance for river regulation.
Ning et al. (2026) studied this question.