OrcaFlex User Group 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 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 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 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 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 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 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