An Aerator Impeller Inspired by Eagle Leaf Tips for Improved Energy Efficiency

Aerators are extensively utilized in wastewater treatment applications; however, they encounter challenges, such as high energy consumption, which has a direct impact on their environmental and economic benefits. Among these challenges, the leakage occurring at the top gap of the aerator impeller is a significant factor leading to impeller loss. Installing leaf tip winglet on the impeller can partially inhibit the flow through the top gap and enhance the performance of the impeller. This research focuses on optimizing the meridian and rotary surface parameters of the impeller using the Taguchi design methodology. The optimized model is then chosen, and CFD software is employed to simulate the impact of various leaf tip winglet widths on the internal flow and performance of the aerator impeller at the suction surface. The findings reveal that increasing the width of the leaf tip winglet can diminish the flow through the top gap and delay the formation and shedding of the leakage vortex at the top. Furthermore, it alters the location of the vortex, shifting it away from the suction surface and reducing separation loss. At the highest efficiency point, a 15 mm leaf tip winglet width results in a 0.61% increase in full-pressure efficiency. This study offers valuable insights for the development of energy-efficient aerators.