Study on energy absorption performance of airfoils with traveling wave motion in different school configurations

The airfoil with traveling wave motion can obtain energy from fluid under certain motion parameters, and the school configurations definitely affect the energy absorption efficiency. In this study, we set three NACA0012 airfoil sections as two-dimensional simplified models of the fishlike body. Based on numerical simulation, the energy absorption efficiency of the airfoils in different school configurations is studied. The results show as follows: when only longitudinal interference (tandem configuration) works, the efficiency of the first airfoil fluctuates slightly with the increase of the longitudinal distance, while the efficiency of the second and third airfoils present a simple and harmonic trend. When only lateral interference (parallel configuration) works, the efficiency of both ends of the airfoils gradually decreases with the increase of the lateral distance, while the efficiency of the middle airfoil increases first and then decreases, having a maximum value. When longitudinal and lateral interferences exist simultaneously (triangular configuration), there are optimal longitudinal and lateral distances so that the efficiency of the three airfoils is the highest. Among these three school configurations, the parallel one is the most advantageous for gaining energy from the flow, followed by the triangular one, then the tandem one. This is a completely new energy harness methodology which could be an innovative approach in the future to provide power source energy for the robotic fish for long-endurance missions. Therefore, this study has important research values and application prospects.