Scaled modeling and simulation of ocean wave linear generator buoy systems

Graduation date: 2007Accurate scaled modeling and simulation are critical to advancing ocean wave linear generator buoys. A 100th scaled model of ocean wave generator buoy systems is analyzed by solving the Navier-Stokes equations. These equations are numerically solved using Computational Fluid Dynamics (CFD) by implementing the front capturing method. In this thesis, winter and summer wave profiles are considered and the heave velocity of an oscillating buoy is studied in order to predict and to understand the power generated by the buoy. The results from the CFD simulations need to be compared with experimental data, thus a wave flume design from a dimensions perspective is presented. In addition, a 100th scaled permanent magnet linear generator design for high efficiency is presented. \ud The ocean buoy design is presented by drawing the transfer function in the heave motion. The frequency domain analysis is overlapped on the wave energy spectra for summer climate condition. MATLAB program scripts are listed for buoy sizing and linear generator design. The linear generator design is verified using Maxwell-2D Finite Element Modeling (FEM) code.\ud From simulations, it was found that given the diameter of the ocean buoy of 4.5m, it can generate 24 kW rms power in winter, however the buoy can only generate 3.3kW rms power in summer considering a damping factor of 0.25.\ud The optimized design of the PM linear generator designed using a 1mm air gap, with an efficiency of 96.5%, produces 2.2 W with a peak thrust of 30 N.\ud The damped frequency of heave motion is plotted and it is found that a 4.5m diameter buoy produces heave motion in the frequency range of the high energy spectrum