Abstract: Small river channels have poor water circulation and low self-purification capacity, while the traditional pumping station suffers from the problem of vibration, cavitation and low efficiency at ultra-low lift operating conditions. To enhance the hydrodynamic force of such rivers, we developed a swing hydrofoil and its calculation model, and studied its water propulsion performance of three swing modes. Numerical calculations were made by using the combination of the realizable k-ε turbulence model and the dynamic grid technology, and the swing mode with better water propulsion effect was tested experimentally. For this hydrofoil, results showed that Mode 3 produced only thrust, while Mode 1 and Mode 2 produced both thrust and resistance. The formation and evolution of vortices are the key factors affecting the performance in water body propulsion. Both propulsion efficiency and pump efficiency are significantly higher in Mode 3 than in those of the other two modes. At a specific frequency with a flow rate of 490 L?s-1 and a lift head of 0.0281 m, Mode 3 has its maximum efficiency of 34.1%, significantly higher than 8.6% of Mode 1 or 9.4% of Mode 2. Swing hydrofoils for water propulsion have the advantages of low lift and large flow, manifesting unique advantages in application to small river basins.

Key words: swing hydrofoil, swing mode, water propulsion, numerical simulation, experimental verification