Abstract
A design method based on a lifting line model is developed to determine the optimum radial circulation distribution on a turbine blade, which will produce the maximum output power for a given tip speed ratio and a given number of blades. The resulting optimum circulation distribution is used in order to determine the preliminary shape of the turbine blade. The blade shape is then refined by using an analysis method, based on a vortex-lattice scheme, in combination with a nonlinear optimization method, which determines the blade geometry that will produce the highest output power. Finally, the effect of nonuniform current inflow on the performance of a turbine is also addressed by coupling the vortex-lattice method with a viscous flow solver.