A Comparative Study of Control Algorithms on Wind-Powered Cargo Vessel Performance

Wind propulsion for commercial cargo ships is rapidly emerging as a viable technology to reduce greenhouse gas emissions. Naval architects frequently adapt methods and tools originally designed for sailing yachts to create these modern "sailing" vessels. Typically, steady-state Performance Prediction Programs (PPPs) are used to estimate vessel speed, leeway, heel, and other factors under various wind conditions. However, these tools do not account for dynamic factors such as unsteady sail forces due to ship motions in waves, gusty winds, or the vessel's control system dynamics. This paper presents a comparative analysis of control algorithms and their impact on the performance of a wind-powered cargo vessel. We utilize a Dynamic Performance Prediction Program (DPPP) that integrates an unsteady 3D fully nonlinear potential flow hydrodynamic solver with an efficient lifting-line aerodynamic model. This approach allows us to assess the performance implications of different control strategies. The findings reveal how various control strategies influence sailing performance, highlighting the potential benefits and trade-offs in unsteady, real world environmental conditions.