A CFD simulation study of air-lift artificial upwelling based on Qiandao Lake experiment

- We have established a CFD model to analyze how upwelling device parameters influenced the efficiency.
- Qiandao Lake experiment proved the accuracy of the simulation model.
- The circular type nozzle performs better than the cross shape.
- The injection nozzle in deeper position performs better than in shallower one.

The application of artificial upwelling technology could increase the primary marine productivity by bringing nutrient-rich subsurface water to surface. Although the artificial upwelling has been extensively studied, few numerical simulation studies on artificial upwelling device parameters, such as nozzle type, injection depth and injection hole diameter, have been conducted. This paper establishes a computational fluid dynamics (CFD) model to theoretically analyze how the upwelling efficiency were influenced by injection nozzle type, diameter of injection hole and injection depth. The comparison between the simulation results and the corresponding experimental data obtained in Qiandao Lake experiments firstly proves the accuracy of the predictions of CFD model in terms of upwelling efficiency via changing the parameters of the artificial upwelling device; secondly, it also indicates that the circular type of an air injection nozzle installed in deeper water depth with larger injection holes brings more deep water to the surface. It is believed that this study may shed some light on the improved design of an artificial air-lift upwelling device.