Numerical Analysis and Experimental Validation of Added Resistance on Ship in Waves

In this study, the added resistance of a liquefied natural gas carrier (LNGC) in the presence of waves is studied experimentally and numerically. The ship model is an LNGC designed by Samsung Heavy Industries (SHI). Experiments on ship motion responses and added resistance under head sea conditions were conducted at the Seoul National University and SHI. The influences of the experimental methods (captive and self-propulsion methods), incident wave amplitude, and regular and irregular wave conditions on the added resistance are evaluated using the same model ship set at different scales. In the numerical studies, the motion responses and added resistance are obtained using three methods—the strip method by adopting momentum conservation; Rankine panel method using pressure integration; and computational fluid dynamics method, using the difference in the resistances in waves and calm water. The experimental and numerical results under various conditions are compared, and the characteristics of the experimental and numerical results are discussed. Unlike the resistance in calm water, additional resistance occurs because of winds, waves, current, and for other reasons in a seaway. This aforementioned resistance, caused by environmental conditions, is called an added resistance. Among the various types, the added resistance caused by water waves is investigated in this study.