Discussion of "modeling and Prototype Testing of Flows over Flip-Bucket Aerators" by Penghua Teng and James Yang

The Authors propose an interesting comparison between physical scale modeling, CFD modeling and field observations related to a unique spillway with flip buckets and built-in aerators. Despite the field observations are mainly qualitative, the Discussers would like to thank the Authors for sharing with the scientific community these results. Indeed, such analysis are very valuable but are too rare. Physical models and CFD are both modeling tools. They both suffer limitations and, consequently, their results need to be carefully and objectively discussed and validated. Comparison to quantitative prototype data is the only way to proof the validity of a modeling technique for real projects. However, such validation data remain sparse and rare, in particular considering large hydraulic structures.
In the following, the Discussers aim to raise one issue in the Authors’ research and to highlight recent contributions and existing datasets, which are of direct relevance for the interpretation and discussion of the Authors’ results.