OrcaFlex User Group 2003 www.orcina.com Slide 1 of 7
OrcaFlex - Development Priorities
Introduction
• List of Development Priorities as seen by Orcina
• Influenced by– Feedback from Clients
– Informed by Orcina use on Consultancy work
– Our own understanding of the code enhanced features
– Occasional paid developments
• Can never promise to implement
• Following list is in no particular priority or order
OrcaFlex User Group 2003 www.orcina.com Slide 2 of 7
OrcaFlex - Development Priorities
• Non-linear & suction seabed– Implement a user specified piecewise linear force vs. depth of
penetration curve– allows non-linear soil reactions, and also modelling the effects
of suction on line emergence
• 3D seabeds– allows user defined 3D seabed profile– means friction bias model would have to change
OrcaFlex User Group 2003 www.orcina.com Slide 3 of 7
OrcaFlex - Development Priorities
• OrcaFlex speed up– use of implicit and / or variable step integration schemes– adopting FE techniques such as static condensation– ‘Model Analyser’ to help user improve the model and run time
• Frequency Domain– could linearise everything and do the usual thing– alternative: FFT an OrcaFlex white noise simulation to
give ‘non-linear’ RAOs– using these is more accurate
OrcaFlex User Group 2003 www.orcina.com Slide 4 of 7
OrcaFlex - Development Priorities
• Vessel motions via force RAOs & convolution– will allow vessel motions to be calculated from the forces
acting– includes the effects of attached lines– ideal for jetty moorings, tandem moored vessels and bundle
tow-out analysis– users will need to define a hydrostatic stiffness matrix
• Rendered graphics– to produce 3D rendered images of simulation or data files– available as an add-on option– Perspective and hidden line allowed for– can ‘fly’ through the model
OrcaFlex User Group 2003 www.orcina.com Slide 5 of 7
OrcaFlex - Development Priorities
• Pipe flooding / slugging– simulate transient mass flow in lines
• Payout of OrcaFlex lines– aka ‘Node Feeding’– ability to change line length during simulation– winch wire does this but excludes mass and hydrodynamic forces– problem is we are creating / destroying mass!
OrcaFlex User Group 2003 www.orcina.com Slide 6 of 7
OrcaFlex - Development Priorities
• Wake deficit– model altered flow behind upstream line– impacts on downstream line– 2D theory (Huse), needs generalising to 3D
• Spar buoy ID– allow specification of internal diameter– then no need for added mass / lost buoyancy approaches
OrcaFlex User Group 2003 www.orcina.com Slide 7 of 7
OrcaFlex - Development Priorities
• VIV developments– allow export of Shear7 Structural file– full integration of Shear7 with OrcaFlex (as per VIVA)– further work on vortex tracking– coupling with CFD
• Hydrodynamic modelling– Range of interfaces to other hydrodynamic packages– library of standard vessel hydrodynamics
• Automation– further developments to OrcaFlex automation
