Optimization Study of Wave Energy Device Parameters Base on Multivariate Objective Optimization

This paper proposes a mathematical model based on an oscillating body-type dual-floater wave energy converter. The purpose of it is to find a group of damping coefficients to achieve maximal output power. In the model construction, the converter's dynamics in experimental ocean conditions are simplified to 2 dimensions: heaving and pitching. A system of ordinary differential equations (ODEs) is built up to describe the system's dynamics and direct numerical simulation (DNS) is used to get a solution. Considering the simplicity of these equations, inertial and noninertial coordinate systems are chosen to analyze the whole device and the vibrator only, respectively. Based on the related parameters of the converter, a possible range of [100000], [100000] for damping coefficients is presumed. With the help of ODEs, a maximal output power of P = 197. 607W is achieved under optimal damping coefficients of C
r
= 100000, C
r
= 87000. It is noteworthy that the mathematical model mentioned in this article compromises precision under large wave amplitude for a more accurate solution under small wave amplitude with an acceptable computational complexity. During the process of finding optimal parameters, the adaptive step size is used to reduce computational costs with a given precision. In the next stage, an analytical expression of the ODEs is expected to be found, which will overcome the computational complexity problem of the DNS method.