Picture taken from: "Vortex Induced Motions of Semi Submersible with Four Square Columns", O. Rijken, S. Leverette and K. Davies, DOT 2004, New Orleans, USA.
General information
Vortex Induced Motions (VIM) of a floater are the result of the exciting forces by vortex shedding on the hull of a bluff body, causing response near the resonant period of any of the six degrees of freedom motions. VIM is identical to VIV (Vortex Induced Vibrations), but due to the much longer periods of the motions, the vortex induced vibrations of floating structures are more commonly referred to as Vortex Induced Motions (VIM). VIM can occur on any bluff body exposed to current, such as Spars, semi-submersibles, TLPs and buoys, provided the vortex shedding frequency is close or equal to the natural period of the floating body.
The Trials and Monitoring Department can be involved in full-scale measurements of Vortex Indiced Motions.
Vortex Induced Motions (VIM) of a floater are the result of the exciting forces by vortex shedding on the hull of a bluff body, causing response near the resonant period of any of the six degrees of freedom motions. VIM is identical to VIV (Vortex Induced Vibrations), but due to the much longer periods of the motions, the vortex induced vibrations of floating structures are more commonly referred to as Vortex Induced Motions (VIM). VIM can occur on any bluff body exposed to current, such as Spars, semi-submersibles, TLPs and buoys, provided the vortex shedding frequency is close or equal to the natural period of the floating body.
The Trials and Monitoring Department can be involved in full-scale measurements of Vortex Indiced Motions.
Services & Activities
The Offshore Department has a lot of experience in the testing of Vortex Induced Motions of Spars, Semi submersibles and TLPs in the Depressurised Towing Tank. For testing Vortex Induced Motions (VIM), this tank is specially suited due to its long tow length and large cross section (main dimensions: 240 x 18 x 8 m). Uniform current flow is simulated by towing the model in calm water. During these tests the VIM response of the structure is determined and the effectivity of VIM reduction devices (such as helical strakes) is determined and optimised.
The Offshore Department has a lot of experience in the testing of Vortex Induced Motions of Spars, Semi submersibles and TLPs in the Depressurised Towing Tank. For testing Vortex Induced Motions (VIM), this tank is specially suited due to its long tow length and large cross section (main dimensions: 240 x 18 x 8 m). Uniform current flow is simulated by towing the model in calm water. During these tests the VIM response of the structure is determined and the effectivity of VIM reduction devices (such as helical strakes) is determined and optimised.
Facilities & Tools
VIM model tests are carried out in the following MARIN facilities :
VIM model tests are carried out in the following MARIN facilities :
- Offshore Basin: DP model tests in combined current, waves and wind
- Depressurised Towing Basin: towing tests
The following tools are used to study Vortex Induced Motions (VIM) :
Software Sales
Some software tools are available for commercial use outside MARIN. A complete overview of these software tools for sale can be found under Software Sales.
Some software tools are available for commercial use outside MARIN. A complete overview of these software tools for sale can be found under Software Sales.
Experience
The list below gives a review of VIM projects carried out at MARIN:
The list below gives a review of VIM projects carried out at MARIN:
- Perdido Regional Host Spar (Technip/Shell, 2006)
- Blind Faith semi (Chevron/AkerKvaerner, 2005)
- Tahiti Spar (Technip/Chevron, 2004)
- Genesis Spar (Technip/Chevron, 2003)
- Mad Dog Spar (Technip/BP, 2002)
- Holstein Spar (Technip/BP, 2002)
- Murphy Medusa Spar (McDermott/Murphy, 2001)
- King Spar (BP Amoco, 1999)
The following Joint Industry Project (JIP) will be focussed on Vortex Induced Motions :
- Joint Industry Project ‘Current Affaires’
Most recent papers on Vortex Induced Motions (VIM) presented by MARIN
(complete overview of papers can be found under Publications)
(complete overview of papers can be found under Publications)
So far no entries have been published.
Most recent articles in MARIN Report on Vortex Induced Motions (VIM)
(complete overview of papers can be found under Publications)
(complete overview of papers can be found under Publications)
So far no entries have been published.
Contact
For more information on how MARIN can help your organisation with the issue of Vortex Induced Motions, please contact:
For model test activities and simulations : Offshore Department
For full scale measurements : Trials and Monitoring Department
For more information on how MARIN can help your organisation with the issue of Vortex Induced Motions, please contact:
For model test activities and simulations : Offshore Department
For full scale measurements : Trials and Monitoring Department