As CFD results are very dependent on generated grids, several tests are done on mesh generations to show the convergence of the results. In this study, CFD method was used to analyze the motion and the added resistance of a given ship with head sea conditions. Also, Yang and Kim (2017) predicted added resistance in short waves for the hull with several different bow shapes using CFD and showed promising results. (2015) applied Cartesian-grid-based method to the added resistance calculation.
(2015) estimated the added resistance of the KRISO Container Ship (KCS) by using full scale model with commercial code, Star-CCM+. (2013) compared the motion and added resistance of the KVLCC2 and Tezdogan et al. Many studies have been made using CFD methods. However, the computation time is still a major issue in CFD since most of the simulation still needs a lot of computation time compared to the potential based methods. Nonlinear effects are especially important for short wavelengths and the viscous effects are more realistic than the inviscid model. CFD has gained interests since it could consider nonlinear effects and viscous effects. Nowadays, development of computers gave rise to new field called Computational Fluid Dynamics (CFD).
Experiments are desirable and needed, but the expenses are rather expensive than the computational methods. However, potential based methods have limitations since it has difficulty in considering the nonlinear effects and the viscosity effects. (2016) investigated the added resistance by model tests. (2014) predicts the added resistance with potential based methods and Lee et al. Traditionally, potential based numerical methods and experimental studies are applied to predict the added resistance more correctly. As a results, predicting added resistance became one of the highly interested domain in seakeeping problems. Accurate prediction of the added resistance of the ship is needed since it could give variety of information about the efficient hull shapes. This regulation caused ship building companies to build more efficient ships and to achieve this goal, reducing added resistance became necessary. International Maritime Organizations (IMO) has released Energy Efficiency Design Index (EEDI) regulation recently. The calculated results were compared and validated with the experimental results. Several grid tests were conducted to achieve the converged motion and resistance values. The heave and pitch motions were calculated along with the added resistance and the wave contours were obtained. The wavelengths varied from half the ship length to twice the ship length and the design speed was selected for the velocity. Unsteady Reynolds Averaged Navier-Stokes equation (RANS) was numerically solved and the volume of fluid (VOF) approach was used to simulate the flows.
In this study the motion response and the added resistance of the LNG carrier in head waves were computed using the commercial computational fluid dynamics (CFD) code Star-CCM+. As a results ship added resistance is one of the key consideration in designing a highly efficient ship and many experiments and numerical methods are conducted to predict the added resistance. International Maritime Organization (IMO)'s recent Energy Efficiency Design Index (EEDI) regulation for new ships has increased interests in ship efficiency.