MECH0066 Ship Dynamics

Module Overview

This module is an advanced course in ship dynamics covering the analysis methods available for ship stability and trim, the response of ships and offshore structures to waves (seakeeping), describing waves as both regular and irregular processes and methods to analyse the structural dynamics of marine vehicles.

The aim of the module is to give students an advanced theoretical grounding in one of the fundamental analytical discipline fields of Naval Architecture and Ocean Engineering.

Topics Covered

• Hydrostatics and Stability
• Ocean Waves and Random Processes
• Seakeeping
• Ship Vibrations (Theory)
• Ship Vibrations (Practice)

Learning Outcomes

Upon completion of this module students will be able to:

Hydrostatics & Stability:

• Calculate hydrostatic data for any floating structure and predict the influence of geometric parameters on a vessel’s stability characteristics.
• Interpret a vessel’s response to any loading condition from lever and moment curves.
• Calculate and assess a vessel’s damage stability response.
• Undertake an inclining experiment according to industry best practice.

Ocean Waves & Random Processes:

• Describe the fundamental principles of ocean wave theories and random processes relating to waves and vessel motions.
• Calculate the characteristics and behaviour of regular ocean waves and apply techniques to predict and characterise the ocean irregular wave environment.
• Use probabilistic techniques to determine the probability of occurrence of wave and ship motion events.
• Describe the concepts and processes of seakeeping analysis in the design process, ship motion model experiments and ship hydroelasticity.

 Seakeeping:

• Apply techniques to predict the roll, pitch and heave motion of a vessel travelling in regular waves and irregular waves and understand the physical mechanism of various design/operational options for motion control and reduction.
• Understand the concepts of dynamic stability, motion characters including linear response for resonance, parametric rolling, drift/sum frequency/difference frequency motions.

Ship Vibrations (Theory & Practice):

• Calculate the dynamic response of vibrating single-degree-of-freedom (SDOF) systems and multi-degree-of-freedom (MDOF) systems.
• Calculate the natural frequency of continuous systems using Rayleigh’s method.
• Calculate the natural frequencies and mode shapes of continuous systems using simple beam theory and calculate the forced vibration response of these systems.
• Describe the limitations of vibration analysis based on simple beam theory. Describe higher order beam theory and when this is most applicable.
• Describe the various forms of, issues with & sources of ship vibrations, and implications for ship design.
• Describe the sources and effects of mechanical system vibrations and outline limits/regulations/treatment methods for airborne noise.
• Conduct a vibration assessment of shipborne structure.

Method of Instruction

This module is taught through:

• Lectures
• Tutorials
• Practical laboratory classes