RANS Analysis of the Motions and Added Resistance for KVLCC2 in Head Regular Waves: Fid-Bau Portal

RANS Analysis of the Motions and Added Resistance for KVLCC2 in Head Regular Waves

Yao, Jianxi / Su, Yan / Song, Xuemin / Liu, Zuyuan / Cheng, Xide / Zhan, Chengsheng

Abstract The motions and added resistance for KVLCC2 models in head regular waves are predicted by using the expanded RANS solver on OpenFOAM platform. The computed added resistance consists of not only the added resistance due to pure hydrodynamic effect, that is obtained by integrating pressure and viscous stress over hull surface, but also the mean inertia forces due to the surge acceleration and the coupled motion of heave and pitch. Various conditions, i.e. ship speed, wave height, scale ratio, and spring stiffness are considered during the computations, and their influences on the components of added resistance and wave-induced motions are analyzed. The computed results show that spring stiffness, wave height, and scale effects have very little influences on heave and pitch for Froude number 0.142. However, the added resistance due to pure hydrodynamic effect and the total added resistance are affected considerably by wave height and scale ratio. The computed mean inertia force based on first-order heave and pitch is almost equal to the one based on the original result of heave and pitch, indicating the first-order heave and pitch play a major role in the contribution. The computed added resistances with the contribution of mean inertia forces and the first-order heave and pitch RAOs agree well with the available experimental data in general, demonstrating the present computations are effective and reliable. Moreover, this study supports the conclusion that the mean inertia forces, especially the one due to the coupled heave and pitch, should be accounted for when determining added resistance, for the purpose of comparing computed results with experimental data which usually does contain the inertia effects.