Course content

"Understanding and managing the forces of the sea for safe and resilient operations—TMR4215 prepares students to master sea loads and shape the future of marine and ocean engineering!"

This course focuses on the behavior of displacement ships and offshore structures in the marine environment, emphasizing both traditional methods and state-of-the-art tools to assess sea loads and responses. Students will explore key design and operational criteria to ensure safe, effective, and efficient marine activities. A central question frames the course: How can we ensure safe and successful marine operations under realistic environmental conditions?

We will address essential questions such as: Which sea conditions are relevant to specific marine structures? How can sea loads and motions be classified based on physical phenomena and nonlinearities? Which simplified prediction methods are useful for practical applications, and what are their reliability limits?The course covers several key topics:

• Marine Environment Characterization: Waves, wind, and currents are analyzed in relation to their impact on marine structures.
• Load and Motion Analysis: Linear and second-order wave effects, viscous forces, and steady currents are studied. Special focus is given to phenomena such as vortex-induced oscillations and galloping.
• Stationkeeping and Dynamic Positioning: Mean and slowly-varying motions are explored, with an emphasis on dynamic positioning systems for offshore platforms.
• Nonlinear Wave-Body Interactions: Issues like slamming, water entry/exit, and wave-induced motions are covered, using simplified approaches to gain practical insights.

The course also addresses how to reduce wave-induced motions through passive and active tools like anti-roll devices and dynamic positioning. While focusing on simplified methods for quick and practical calculations, the course highlights examples from modern marine applications, offering students the opportunity to engage with practical problems.

Learning outcome

General objectives of the course are to:

• Gain a clear understanding of critical issues at sea, including key response variables and the safety and operational criteria relevant to marine units.
• Develop a solid foundation in the orders of magnitude for environmental conditions, structural natural periods, and resonant/unstable motions.
• Acquire practical knowledge of fluid-structure interaction phenomena and apply simplified methods for design, operational planning, or quick verification of complex models.

Upon completing the course, students will be able to:

• Identify critical environmental and operational conditions for standard ships and offshore structures.
• Estimate response variables (motions, accelerations, relative motions) using simplified linear theory and assess operational limit criteria for marine units.
• Understand second-order and higher-order effects in wave-body interactions and estimate added resistance in short waves, knowing the limits of approximated methods.
• Evaluate relative importance of potential-flow and viscous-flow effects for mean and time-varying loads in waves, current and wind, using simplified models and practical techniques.
• Identify and assess vortex-induced vibrations (VIV) and vortex-induced motions (VIM), and distinguish between VIV and galloping phenomena.
• Understand the principles and challenges of stationkeeping and dynamic positioning and characterize related control forces, damping mechanisms and restoring effects.
• Roughly assess phenomena like slamming and water on deck using simplified prediction methods to evaluate operational criteria.

Learning methods and activities

Key course features are:

• Hands-on Learning with Simplified Methods. While incorporating examples from modern marine applications, the course emphasizes simplified tools for quick calculations relevant to ship and platform design.
• Practical Examples. Exercises and case studies focus on practical marine scenarios, allowing students to apply theoretical concepts to actual marine structures under simplified conditions.
• Continuous Learning Checks. Quizzes are integrated into the lectures to reinforce students' understanding and ensure alignment with course content.

Lectures: Students are encouraged to attend all theoretical and exercise sessions. Participation is essential for a deep understanding of the material, and exercises will offer hints and strategies for solving relevant marine engineering problems. Two to three student assistants and a PhD administrator will provide guidance and support during the exercise sessions.

Methods of Assessing Students Learning: Throughout the course, learning will be checked using integrated quizzes during lectures, ensuring continuous progress aligned with the theoretical and practical content. Additionally, a set of sample questions will be provided at the start of the course to guide learning and facilitate group discussions. Weekly exercises will provide an opportunity for students to apply theory to practical examples, with solutions available on the Online Learning Platform.

Compulsory assignments

• Exercises

Recommended previous knowledge

It is recommended that students have completed the courses:

• TMR4247 - Marine Technology - Hydrodynamics
• TMR4182 - Marine Dynamics

Students lacking this background are encouraged to review the relevant material before taking the course.

Required previous knowledge

Familiarity with mathematical symbols and to have basic knowledge of fluid mechanics, water waves, and hydrodynamics.

Course materials

Primary Text: O.M. Faltinsen, Sea Loads on Ships and Offshore Structures, Cambridge University Press, 1990 (also available in Chinese and in Korean).

Lecture Notes: M. Greco, TMR 4215: Sea Loads, NTNU. They can be downloaded from the Online Learning Platform of the course. There, the slides of the lectures are also available.

Credit reductions