Abstract
Large scale coherent motions around marine and hydrokinetic (MHK) machines can significantly increase the structural loading and affect the overall performance of the machines. Characterization of the approach turbulence and their impact on the instantaneous response of MHK devices is essential for improving their design and performance. This preliminary study investigates the effect of turbulence and dominant energetic coherent structures induced by a vertical cylinder on the structural load and energy production in a model MHK turbine. Results show that the power generated by the turbine is significantly reduced by the presence of the cylinder. This reduction depends on the distance from the cylinder and the level of turbulence around the rotor area.