DESIGN OF BLADES FOR MARINE CURRENT TURBINES DAVID H. MENÉNDEZ ARÁN, YE TIAN AND SPYROS A. KINNAS OCEAN ENGINEERING GROUP, DEPARTMENT OF CIVIL, ARCHITECTURAL AND ENVIRONMENTAL ENGINEERING, THE UNIVERSITY OF TEXAS AT AUSTIN, TEXAS ABSTRACT This paper describes the design of marine current turbine blades based on the results of a fully-aligned lifting line optimization model. The geometry is generated by assuming chord and camber distributions in order to reproduce a given loading on the turbine blade. This geometry is then analyzed with two three-dimensional potential flow solvers: a low-order panel code and a vortex lattice model. Accuracy and stability for different discretization schemes is studied, as well as the effect of different wake alignment strategies. Keywords: Marine turbine; blade design; potential flow NOMENCLATURE Flow parameters:  Current speed  ݎRotational speed  Tip Speed Ratio;  ൌ ሺሻ  ⁄  ∗ Total inflow relative to the blade sections ݑ ௔ ∗ Induced axial velocity ݑ ௧ ∗ Induced tangential velocity ߚPitch angle of the undisturbed flow, relative to the blade sections ߚ ௜ Pitch angle of the total inflow  ∗ relative to the blade sections ܦDrag on a blade section ܮLift on a blade section Ȟ Circulation around a blade section ߶ Perturbation velocity ݖ ,ݕ ,ݔCartesian coordinates ߴ ,ݎ ,ݔCylindrical coordinates Turbine characteristics:  Number of blades  Radius of the turbine ݎ ௛ Hub radius  Chord length ܥ ௅ Sectional lift coefficient  ௠௔௫ Maximum camber ߠBlade pitch angle ߙAngle of attack 403