Numerical Prediction of Added Power in Seaway

The paper describes a numerical approach to predict required added power for propulsion in waves. Such predictions are important to address fuel consumption in seaway and define suitable operating point and sea margin, as well as for routing optimization and hull performance monitoring. Added resistance and, in general, drift forces and moments due to waves are key input parameters for added power requirements. The three-dimensional Rankine source-patch method was used to compute them. The method solves the problem in the frequency domain, linearizing wave-induced motions around the fully nonlinear steady flow. The added power software combines added resistance and drift forces and moments in irregular waves with wind forces and moments, calm-water maneuvering forces and moments, rudder and propeller forces, and propulsion and engine model and provides associated resistance and power as well as changes in ship propulsion in waves. The approach is demonstrated for a container ship to compare predictions with full-scale data.