Dynamic Modeling and Simulation of a Spar Floating Offshore Wind Turbine with Consideration of the Rotor Speed Variations

Mohammed Khair Al-Solihat*, Meyer Nahon, Kamran Behdinan

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


This paper presents a rigid multibody dynamic model to simulate the dynamic response of a spar floating offshore wind turbine (FOWT). The system consists of a spar floating platform, the moorings, the wind turbine tower, nacelle, and the rotor. The spar platform is modeled as a six degrees-of-freedom (6DOFs) rigid body subject to buoyancy, hydrodynamic and moorings loads. The wind turbine tower supports rigid nacelle and rotor at the tip. The rigid rotor is modeled as a disk spinning around its axis and subject to the aerodynamic load. The generator torque control law is incorporated into the system dynamics to capture the rotor spinning speed response when the turbine is operating below the rated wind speed. The equations of motions are derived using Lagrange's equation in terms of the platform quasi-coordinates and rotor spin speed. The external loads due to hydrostatics, hydrodynamics, and aerodynamics are formulated and incorporated into the equations of motion. The dynamic simulations of the spar FOWT are performed for three load cases to examine the system eigen frequencies, free decay response, and response to a combined wave and wind load. The results obtained from the present model are validated against their counterparts obtained from other simulation tools, namely, FAST, HAWC2, and Bladed, with excellent agreement. Finally, the influence of the rotor gyroscopic moment on the system dynamics is investigated.

Original languageEnglish
Article number081014
JournalJournal of Dynamic Systems, Measurement and Control, Transactions of the ASME
Issue number8
StatePublished - 1 Aug 2019
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2019 ASME. All Rights Reserved.

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Information Systems
  • Instrumentation
  • Mechanical Engineering
  • Computer Science Applications


Dive into the research topics of 'Dynamic Modeling and Simulation of a Spar Floating Offshore Wind Turbine with Consideration of the Rotor Speed Variations'. Together they form a unique fingerprint.

Cite this