Change search
ReferencesLink to record
Permanent link

Direct link
Coupling of marine riser and tensioner system
Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, Department of Marine Technology.
2011 (English)MasteroppgaveStudent thesis
Abstract [en]

A coupled model of a marine riser and a tensioner system is built. The riser is modeled using the multi-body dynamics program MSC Adams, and the tensioner system using the powerful controls and systems simulation tool, MSC Easy5. The hydrodynamic forces on the marine riser are calculated according to linear wave theory, and implemented in the model using a custom made subroutine. The riser is modeled using flexible beam elements according to Timoshenko beam theory.

The tensioner system is modeled using moments of fluid system and body mechanics. The system is solved using equations of equilibrium of fluid momentum, mass and energy. For the unfamiliar reader, an introduction to deep sea oil exploration and production is given. Each subsystem included in the model is explained. The mode of working of the more complex subsystems is presented, followed by a discussion of the simplifications made to include them in the model.

The hydrodynamic force module is based on linear potential theory of long waves, and Morison’s equation for oscillating structure in oscillating flow. An introduction to wave theories with derivation of the necessary equations is given, together with a thorough discussion of hydrodynamic coefficients.

An introduction to the mechanics of fluid systems is presented, to give the reader the knowledge to understand the underlying principles of the Easy5 tensioner model.

A rough guide to MSC Adams and MSC Easy5 explaining normal usage of the programs, alterations made to them and use of the 4subsea interface, is presented. Theory regarding computational methods of solving ordinary differential equations is also offered.

Finally all results are verified by analyzing similar models in the widely used and highly acknowledged global analysis program for slender marine structures RIFLEX. Excellent compliancy is found for the hydrodynamic force module and the forced vessel motion subroutine. The coupled marine riser and tensioner model shows how tension between lower marine riser package (LMRP) and blow-out preventer (BOP) becomes a critical parameter.

Place, publisher, year, edition, pages
URN: urn:nbn:no:ntnu:diva-15473OAI: diva2:491809
Available from: 2012-02-07 Created: 2012-02-07 Last updated: 2012-02-07Bibliographically approved

Open Access in DiVA

fulltekst(4652 kB)928 downloads
File information
File name FULLTEXT01.pdfFile size 4652 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
Department of Marine Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 928 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 257 hits
ReferencesLink to record
Permanent link

Direct link