Multiple level modeling and assessment of ship maneuvering in extreme waves
Abstract
The general objective of the proposed research is to contribute towards the developmentof integrated capability for carrying out objective assessments of the maneuveringbehavior of naval vessels in extreme waves. Original research will be performed inthree different directions, as follows:a) In the mathematical modeling of ship motions in extreme waves. Here the emphasiswill be on deriving the suitable form of the equations of motion at three different levelsof detail (simple qualitative model, intermediate model and full 6 d.o.f. model); on thecalculation of the loads (hydrodynamic reaction and wave loads); and on the modelingof the control devices (propeller and rudder).b) In the efficient and complete identification of those operational scenarios where anaval vessel is incapable to follow the commanded course or execute intendedmaneuvers. Different research approaches from nonlinear dynamical systems theorywill applied, assuming a regular and an irregular wave environment. For regular seas,a steady-state continuation technique will be adapted to this problem, combined withFloquet-type stability analysis, focused on the turning motion states evolution as keycontrol parameters are varied. For irregular seas, the concept of coherent sets in phasespace will be exploited. In this respect, a trajectory-clustering scheme will be furtherdeveloped and implemented that will be capable to automatically discriminate betweensuccessful and unsuccessful patterns of ship turning in waves.c) In the characterization of a vessels fitness to perform successfully in givenenvironments. This will involve the derivation and use of suitable performanceindicators relying on efficient probability calculation schemes. In this direction, themethod of critical wave groups developed by the proposing team will be modified inorder to deal with the concept of rarity of maneuvering failure events. It will bebenchmarked against the phase space calculations of paragraph (b).Systematic efforts for verifying and validating the applied calculation schemes will bepart of this work.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- N629092012052
Entities
People
- Kostas Spyrou
Organizations
- Office of Naval Research
- United States Navy
- University of Strathclyde