Open Access

ARTICLE

Six-Degree-of-Freedom Motion Analysis of High-Speed Craft Navigating through Variable Marine Environments

Xiaoyang Wu¹, Wenchao Han², Min Kuang^2,*, Xinqi Wang², Wenhao Xie²

1 China Coast Guard Academy, Ningbo, 315801, China
2 Ningbo Key Laboratory of Green Shipping Technology, Faculty of Maritime Transportation, Ningbo University, Ningbo, 315211, China

* Corresponding Author: Min Kuang. Email:

(This article belongs to the Special Issue: Recent Advancements in Wave Dynamics Models for Fluids: Analytical and Numerical Approaches)

Fluid Dynamics & Materials Processing 2025, 21(9), 2201-2223. https://doi.org/10.32604/fdmp.2025.067081

Received 24 April 2025; Accepted 13 August 2025; Issue published 30 September 2025

Abstract

The dynamic behavior of high-speed craft navigating through variable sea states plays a pivotal role in ensuring maritime safety. However, many existing simulation approaches rely on linear or overly simplified representations of the marine environment, thereby limiting the fidelity of motion predictions. This study explores the motion characteristics of a 4.5-t high-speed vessel by conducting fully coupled numerical simulations using the STAR-CCM+ software. The analysis considers both calm and varying sea conditions, incorporating fluctuations in wave height, wavelength, and wind speed to reflect more realistic operating scenarios. Simulation results reveal that the vessel’s hydrodynamic response is highly sensitive to changes in sea state. As conditions deteriorate, the free surface becomes increasingly complex, with higher wave amplitudes and more pronounced interactions between the waves generated by the vessel and those imposed by the external environment. These effects lead to significant increases in roll, pitch, heave, and sway motions, thereby imposing greater demands on the vessel’s dynamic stability and operational safety. Furthermore, both hydrodynamic resistance and propulsive thrust exhibit notable dependence on sea state and vessel speed. Total resistance generally increases with rougher sea conditions, while thrust tends to rise with increasing forward speed. Under calm or mildly disturbed waters, a Froude number (Fr) of 0.5 appears to offer an optimal balance for initiating and controlling primary motions such as roll, pitch, heave, and sway. Conversely, in more challenging conditions—such as those represented by a Sea State 3—effective motion control is better achieved at a higher Froude number of approximately 1.0.

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Keywords

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