Graduation date: 2006Commonly proposed ocean wave energy converters (OWEC) use inefficient and maintenance demanding intermediate hydraulic and pneumatic systems. We propose a novel rotary direct-drive OWEC that eliminates these intermediate stages. The new device employs a contactless force transmission system (CFTS) comprising a “piston” and a “cylinder” and a ball screw to spin a conventional rotary generator. We present an analytical model of the OWEC and also propose a numerical technique that performs a coupled fluid-structure interaction simulation of the wave energy device in a 3-D numerical wave flume using a computational fluids dynamics (CFD) code. In previous investigations, the motion of floating bodies was prescribed rather than determined. The current method represents a significant advancement in that it determines the motion of the buoy from the dynamic solution of the fluid flow problem and the dynamic buoy motion problem. The technique was extended to assess the performance of two neighboring buoys and their interference effects.