Application of CFD Simulations to Marine Hydrodynamic Problems

Growing global energy demand and the increasing exploration of the ocean have brought about significant challenges and opportunities in the field of marine engineering and fluid mechanics [1]. This Special Issue features nine cutting-edge research articles that focus on key areas such as submarine flow fields, ship navigation characteristics, wave energy utilization, artificial reefs, the dynamic stability of pontoons, and fish-shaped oscillating wings. Our aim is to provide a platform for researchers, engineers, and academics to exchange ideas and gain new insights, thereby advancing research and technological progress in this field. The topics of the articles featured in this Special Issue can be classified into three categories: underwater structures, surface structures, and surface waves.

The hydrodynamics of underwater structures, including submarines, hydrofoil, reefs, and other simplified structures, have been investigated in several studies. In [2], an investigation into the flow field characteristics of a new submarine model under both 0 and 10° yaw conditions was carried out. By employing Large Eddy Simulation (LES) technology, complex flow phenomena were accurately captured, and the interaction laws between different appendages and the evolution of the wake were revealed. This research offers crucial theoretical support for enhancing the hydrodynamic design of submarines. The hydrodynamic behavior of cylinders under the action of internal solitary waves is analyzed in [3]. Through numerical simulations, the flow field distribution characteristics and force characteristics of the cylinders are determined, offering critical data support for the design of safe marine structures situated in complex ocean environments. The authors of [4] conduct research on the added mass of underwater objects in variable-speed motion using a numerical simulation approach combined with regression analysis and parameter separation analysis. The study investigates the sources and variation patterns of added-mass forces for irregularly shaped small objects, providing new insights to inform the mechanical analysis and design optimization of underwater vehicles. The flow field effects of trapezoidal artificial reefs are evaluated in a study that combines numerical simulations with field surveys [5]. The study comprehensively assesses the flow field effects, stability, and ecological benefits of different reef layouts under various flow velocities, serving as a valuable reference for the rational design and deployment of artificial reefs. The authors of [6], in a study on fish-like oscillating hydrofoils, investigate the effects of hydrofoil geometric parameters and kinematic parameters on propulsive performance. By analyzing the near-wake structure, the study establishes a correlation between engineering parameters and flow separation, providing key insights for the development of biomimetic propulsion technologies.

The hydrodynamics of surface structures, including ships and wave energy converter, have been investigated in several studies. Ship drift trials were conducted in [7], and the Orthogonal Experiment Method (OEM) was used to analyze the effects of mesh size, turbulence models, and time steps. The reliability of the simulation results was verified, and the Detached Eddy Simulation (DES) method successfully captured the vortex structures around the ship’s hull, highlighting the potential of numerical simulation in ship design. In the field of ship design, a study on the hydrodynamics of bulbous bows for fishing vessels presents a novel numerical reverse design approach [8]. Based on the prototype of an Argentine trawler, this research utilizes the OpenFOAM platform for numerical simulations and combines towing tank experiments for validation. It systematically evaluates the resistance performance of vessels with and without bulbous bows, offering a fresh perspective for the design optimization of small-scale fishing vessels. Research on wave energy utilization is gaining prominence due to the increasing focus on clean and abundant ocean energy resources. The authors of [9] explore parameterized design and employ numerical wave tank technology to analyze the motion response and power output characteristics of a new pontoon-type wave energy converter in regular-wave environments. This work lays a foundation for the engineering application of wave energy conversion technologies.

In the field of wave simulation technology, ref. [10] proposes a high-order spectral method for irregular-wave generation and calibration. By integrating physical wave tank experiments with numerical simulations, this method enhances the accuracy of wave simulations and provides an efficient and reliable tool for research on wave–structure interaction.

The nine studies featured in this Special Issue showcase innovative research from diverse perspectives in the field of marine engineering and fluid mechanics. They not only advance the development of theories and technologies in this field, but also offer valuable guidance for practical engineering applications. We hope that these research findings will inspire readers, promote collaboration between academia and industry, and foster the exchange of ideas to address the complex challenges in marine engineering and contribute to sustainable development.