Simulation of Control Process of Fluid Boundary Layer on Deposition of Travertine Particles in Huanglong Landscape Water Based on Computational Fluid Dynamics Software (CFD)

This research explores the distribution, transport, and deposition of calcium carbonate particles in the colorful pools of the Huanglong area under varying hydrodynamic conditions. The study employs Particle Image Velocimetry (PIV) for real-time measurements of flow field velocity and computational fluid dynamics (CFD) simulations to analyze particle behavior. The findings reveal that under horizontal flow conditions, the peak concentration of calcium carbonate escalated to 1.06%, representing a 6% surge compared to the inlet concentration. Significantly, particle aggregation and settling were predominantly noted at the bottom right of the flow channel, where the flow boundary layer is most pronounced. In the context of inclined surfaces equipped with a baffle, a substantial rise in calcium carbonate concentrations was detected at the channel's bottom right and behind the baffle, particularly in regions characterized by reduced flow velocities. These low-velocity areas, along with the interaction of the boundary layer and low-speed vortices, led to a decrease in particle velocities, thereby enhancing deposition. The highest concentrations of calcium carbonate particles were found in regions characterized by thicker boundary layers, particularly in locations before and after the baffle. Using the Discrete Phase Model (DPM 22), the study tracked the trajectories of 2424 particles, of which 2415 exited the computational channel and nine underwent deposition. The overall deposition rate was measured at 0.371%, with calcium carbonate deposition rates ranging from 4.06 mm/a to 81.7 mm/a, closely matching field observations. These findings provide valuable insights into the dynamics of particle transport in aquatic environments and elucidate the factors influencing sedimentation processes.