Experimental investigation on sail-winged flexible blade turbine

Turbine is the core component of power generation system extracting energy from tidal current.Sail-winged flexible blade turbine is a newly developed device generating power from water.Its blades are made of soft materials,which keep transforming continuously to adapt to the flowing liquid.In this way,the flexible blades can adjust attack angle automatically and make full use of lift and drag to extract energy.Focusing on the power efficiency coefficient(Cp) of the sail-winged flexible blade turbine,the factors that may affect Cp were analyzed with dimensional analysis method.Then the relationship between Cp and arc chord ratio(ACR),side chord ratio(SCR),and blade density(λ) was studied via model tests.The results show that the rotor possesses different optimal values of ACR depending on structures.Cp increases with the increase of SCR.In certain ranges,the starting ability,Cp and the fluctuating of rotor speed become higher with the decrease of λ.So the rotor with lower λ is applicable to low-flow conditions. Otherwise,the rotor with higher λ has lower starting ability,Cp and fluctuating of rotor speed,which is applicable to high-flow conditions to generate higher quality power.Finally,the optimum schemes are proposed,and the optimized turbine is proved to have higher Cp and power generation capacity through model tests.