Orcaflex 11


Orcaflex 11

Summary of key features

  • 3D, nonlinear, large displacement analysis
  • Fully coupled tension, bending & torsion
  • Accurate, efficient and proven FE formulation
  • Robust line compression / snatch modelling
  • External line-on-line clash & sliding contact
  • Internal line-in-line impact & sliding contact
  • Modelling of post-contact behaviour
  • Linear & nonlinear elastic contact stiffness
  • Line slug flow and free-flooding effects
  • Nonlinear time domain (implicit & explicit)
  • Linear frequency domain (1st & 2nd order)
  • Quasi-dynamic analysis
  • Constraints to fix or impose individual DoFs
  • Line feeding (haul in and pay out nodes)
  • Fully coupled vessel – line analysis
  • Comprehensive vessel load modelling
  • Multi-body hydrodynamic coupling
  • Full sum and full difference QTFs
  • Vessel wave shielding (sea state RAOs)
  • Water entry & exit slam loads
  • Full description of wind, wave and current
  • Flat, 2D or 3D seabed profile
  • Linear elastic, non-linear hysteretic & P-y soil
  • Binary and / or text input files
  • Fatigue analysis
  • Extreme value statistics
  • Modal analysis
  • VIV and interference analysis
  • Pipelay and riser code checks
  • Comprehensive range of automation tools
  • Complete Matlab, Python & DLL interfaces
  • Parallel processing (at no extra cost)
  • Batch processing for volume analyses
  • Distributed OrcaFlex optimises multi-licence use
  • Full GUI with wire frame and shaded views

Modelling objects

A wide range of objects, each very powerful, easily allows simple or complex models to be built


  • Fully coupled bending, torsion and axial stiffness
  • Bend Stiffener / Tapered Stress Joint model generation
  • Pre-bend can be modelled (e.g. spool pieces) now with visualisation tool
  • Centrifugal and Coriolis internal flow effects included
  • Slug flow and free flooding options for line contents
  • Multiple coatings and linings can be defined
  • Equivalent pipe setup tool
  • Bending stiffness, drag and added mass can be non-isotropic
  • Axial, bending and torsional stiffness can be nonlinear
  • 3D hysteresis model available for bending
  • Rayleigh damping with or without geometric stiffness
  • Line CofG may be displaced from geometric centre
  • Clumped line attachments, drag chains or flex joints
  • Non-isotropic Coulomb friction with seabed & elastic solids
  • Line Clashing for external clash modelling between lines
  • Line Contact for pipe-in-pipe, piggybacks, J-tube pulls, bend stiffeners, sliding connections, etc., allowing smooth modelling of large relative axial motion including friction
  • Hydrodynamic, aerodynamic and user-defined applied loads
  • Wake Interference (Huse, Blevins,user specified)
  • Partially submerged lines (eg, floating hoses) handled robustly
  • Line drag and lift coeffs can vary with Re or seabed proximity
  • Added mass as a function of submergence or height above seabed
  • Water entry / exit slam loads (per DNV H103, RP-C205)
  • Compressibility specified by bulk modulus
  • Choice of finite element or analytic catenary representation


  • Imposed vessel displacements:
    • first order displacement RAOs
    • prescribed and / or harmonic motion
    • time history motion files
    • externally calculated
  • Loads for calculated vessel motions:
    • first order load RAOs
    • applied loads (thrusters, ice, etc.)
    • 2nd order (low freq.) difference QTFs: full and Newman
    • 2nd order (high freq.) sum QTFs
    • wave drift damping
    • added mass and damping with convolution
    • 6DoF ‘other’ linear and quadratic damping
    • manoeuvring, current and wind loads
    • drag from attached Morison elements
    • loads from attached lines (coupled analysis)
  • Multi-body hydrodynamic coupling between floaters
  • Sea state RAOs (vessel wave shielding, wave jetting, etc)


  • Full 3D and 6D modelling of buoys
  • Lumped option with overall properties
  • SPAR option for co-axial cylinders, each with own properties
  • Fluid loads calculated based on the instantaneous wetted surface
  • Added mass as a function of submergence
  • Water entry / exit slam loads (per DNV H103, RP-C205)
  • Wings for lifting surfaces
  • User-defined imposed loads
  • Compressibility specified by bulk modulus
  • Coulomb friction with seabed and elastic solids


  • Many features to model boundary surfaces and to control lines
  • Shapes with friction for line & buoy contact
  • Plane, cuboid, cylinder (solid/hollow), & bellmouth options
  • Trapped water option for moonpool modelling
  • Drawing option for visualisation purposes


  • Winches with several length or tension control options


  • Links (springs) with linear or nonlinear stiffness & damping


  • Allow individual degrees of freedom for other objects to be constrained
  • Imposed motion via time history or externally calculated


  • Dedicated horizontal-axis turbine object
  • Aerodynamic loading via Blade Element Momentum (BEM) model
  • Blades modelled with beam elements (similar to lines)
  • Prandtl tip and hub loss models
  • Pitt and Peters skewed wake model
  • Blade pitch control via external function
  • Generator control options (constant or externally calculated)
  • Example Python controllers available (including Bladed type DLL wrapper)

Environmental description

Many options to apply environmental loads


  • User-defined water density, kinematic viscosity, temperature
  • User-defined horizontal and vertical density variation
  • Temperature can be constant or vary with depth
  • Kinematic viscosity can be constant or vary with temperature


  • Horizontal, sloping, 2D or 3D seabed surface (smooth or linear)
  • Choice of soil models:
    • linear elastic
    • nonlinear hysteretic (trenching, suction & re-penetration)
    • P-y models (API RP 2A soft clay & sand & user-defined) for vertical and near-vertical line penetration
  • Non-isotropic Coulomb friction in both statics & dynamics


  • User-defined air density
  • Wind velocity can be constant, or API or DNV spectra
  • Wind can also be a time history file of speed and direction
  • Vertical variation factor specified as a profile
  • Full field wind (varies with both space & time)


  • Regular: Airy, Stokes’ 5th, Dean Stream Function, Cnoidal
  • Irregular: ISSC, JONSWAP, Ochi-Hubble, Torsethaugen, Gaussian swell, user-defined, Time History
  • Multiple wave trains for combination sea states
  • Fluid stretching (Wheeler, kinematic or extrapolation)
  • Irregular waves have directional wave spreading option
  • Preview and selection of irregular wave profile
  • Wave kinematics choice (with individual specification for 3D & 6D buoys and lines):
    • Exact (all nodes/buoys, every time step)
    • Grid interpolation at instantaneous object positions
    • Calculation at object static positions only
  • Various wave spectrum discretisation methods:
  • equal-energy (user-defined bounds & interval) – the default
  • equal spacing (arithmetic progression)
  • geometric progression


  • 3D, non-linear
  • Both magnitude and direction can be time varying
  • Horizontal variation factor on magnitude


  • Previous:DNV SIMA 4.0.1
  • Relate Soft

      No information
    Letters A B C D E F G H I J K L M N O P Q R S T U V W X Y Z TOP