Seakeeping Performance of Warship Catamaran under Varied Hull Separation and Wave Heading Conditions: An Integrated Numerical and Experimental Studies

Seakeeping criteria significantly impact ship aspects like speed loss, operational optimization, and structural integrity. This study integrated experimental and numerical methods to evaluate the seakeeping performance of an asymmetrical hull with varying hull separations and wave headings. Experimental Fluid Dynamics (EFD) tests were conducted in a towing tank with irregular waves and a Pierson-Moskowitz spectrum. Concurrently, numerical simulations using the Boundary Element Method (BEM) computed Response Amplitude Operators (RAO) for heave, pitch, and roll motions. The numerical mesh demonstrated a high degree of agreement between RAO peak values from BEM simulations and experimental tests, with discrepancies between 1% and 5%, indicating BEM’s precision in predicting ship responses to wave conditions. The analysis demonstrates that wave heading significantly influences the heave, pitch, and roll motions of the catamaran, with beam seas (90°) presenting the most severe conditions for heave and roll, while head seas (180°) lead to the largest pitch motions. Optimal performance is observed at a separation-to-length (S/L) ratio of 0.4, which minimizes excessive motion across various wave headings. The analysis indicates that while both S/L and wave heading influence vessel motions, the impact of wave heading is more pronounced, with optimal S/L values varying based on specific wave angles. Overall, the findings underscore the critical relationship between hull separation and wave direction, indicating that larger S/L ratios contribute to improved seakeeping performance.