Rotor Structural Design of A Hydrokinetic Turbine

摘要

The blade element method (BEM) was used for the hydrodynamic design of the rotor of a horizontal axis hydrokinetic turbine of 1 Hp (746 W). A water velocity of 1.5m/s with a tip speed ratio of 6.325; an angle of attack and pitch angle of 5 and 0 degrees, respectively; a power coefficient of 0.4382; a drive train efficiency of 70% and a S822 airfoil profile were used for the design. The finite element model (FEM) was successfully used for stress and displacement calculation on the turbine blade under the influence of the gravitational, centrifugal and hydrodynamic loading. The influence of the material and the blade structure shape on its structural behavior were presented and discussed. Safe working stresses and strains were identified and checked. It was found that the stresses produced in all of the analyzed models do not exceed the safe working stresses. Based on these results, the blade models with balsa wood core and layups of glass fiber (type E), stainless steel or aluminum can be selected for manufacturing the blade due to their high stiffness, hydrodynamic loading resistance and low weight compared with the other analyzed models.