Ultra large vessels such as recently engineered FPSOs and FLNG terminals require careful consideration of the effect of water depth in determining their motion characteristics. An efficient numerical implementation of the finite depth Green function, utilizing a series and integral form, has been developed. This is then incorporated in a three dimensional frequency domain panel method program capable of considering forward speed effects. The effect of water depth on the first and second order wave exciting forces and induced motions are studied.
An optimization framework is then developed combining an automated parametric FLNG hull form, the aforementioned in-house developed hydrodynamic analysis tool and an evolutionary optimization solver. In this paper, the principal methodologies used in the development of the finite depth Green function, solving the boundary value problem and key learning from the FLNG optimizations will be discussed.