LAUSR

Artificial downwelling (AD) has emerged as a promising approach to mitigate hypoxia in coastal waters. While several AD systems have been implemented in Japan, Sweden, and China, limited studies have addressed how to optimize discharge parameters to ensure oxygen-rich plumes effectively reach target depths without resurfacing or disturbing bottom sediments. This study investigates the hydrodynamics of oxygen-enriched plumes under the influence of crossflow in stratified environments. A numerical model based on the standard k-ε turbulence closure is developed and applied to simulate AD jets in linearly stratified water with horizontal background velocity. The model is validated against existing laboratory data, showing good agreement. Simulation results are used to derive empirical coefficients describing plume trajectory and penetration depth. Parametric studies are conducted to evaluate the impact of discharge momentum, buoyancy flux, stratification strength, and ambient flow on plume behavior and system efficiency. The findings offer quantitative guidance for designing AD systems under various environmental conditions. Limitations include the use of linear stratification and the standard k-ε model, which may not capture complex turbulence and nonlinear stratification in natural waters. These factors should be considered in future work to enhance model accuracy and applicability.