CFD verification and validation of added resistance and motions of KVLCC2 with fixed and free surge in short and long head waves

► CFD motions and added resistance are conducted for wide range of wave length. ► The added resistance showed a correlation with bow relative motion. ► The decomposition of forces and moments works well for first harmonics. ► Maximum responses occur near resonance and maximum wave excitation force. ► Potential flow predictions are further from the data than CFD.