OrcaFlex 9.2

The latest release of OrcaFlex 9.2 is OrcaFlex 9.2d. To upgrade to OrcaFlex 9.2d, download the following zip file:
OrcaFlex-Patch-9.2a-or-9.2b-or-9.2c-to-9.2d.zip (5.8 MB)
extract all the files it contains to a single folder and then run the extracted file called patch.exe.

This patch can only be applied if you are currently using an earlier release of version 9.2. You may also need access to your original OrcaFlex 9.2 installation CD when you apply it.

The new features introduced in OrcaFlex 9.2 are described below. For full details please see the OrcaFlex help file: OrcaFlex.chm (2.0 MB).

New in Version 9.2d

Lines

Line clash energy and clash impulse results are calculated by numerical integration. This integration is now carried out using a more accurate method. The effect of change is more significant when longer simulation time steps are used. Clashing usually requires short time steps for accurate modelling and so in practical terms the effects of this change are usually insignificant.

Bug fixes

Aborting of batch processing did not work in 9.2c.
The Line Setup Wizard failed with "Access Violation" error messages in 9.2c.

New in Version 9.2c

Multi-threading

Performance has been improved for a number of multi-threaded scenarios when running multiple jobs in batch mode and when running single jobs. Only a minority of models benefit from these improvements but the benefits are significant, especially if you are running on a machine with a large number of processor cores.

Fatigue analysis

Fatigue analysis tabular output can now be customised to reduce memory overheads and reduce spreadsheet file size.

Bug fixes

OrcaFlex licences claimed by the OrcFxAPI DLL (e.g. when using the OrcaFlex spreadsheet) were not being reported in the Orcina Licence Monitor.
Entering points with the same x and y values but different Z values for 3D seabed data resulted in an access violation error being reported.

New in Version 9.2b

Bug fixes

Certain models (typically more complex models) which use the stiffener modelling object were failing to simulate when using the implicit solver.
Results extraction from the OrcaFlex Excel spreadsheet was sometimes hanging and eventually reporting an out of memory error in Excel.
Batch processing had a number of separate bugs. Firstly, the auto save function was not working. In addition the option to save partially completed simulation files when cancelling a batch run was not functioning. Finally, multi-threaded batch simulations could sometimes fail, erroneously reporting "out of memory" or "could not create thread" error messages.
Certain data items are editable even after a simulation has been run. Most notably this includes stress loading factors for Line Types. Such data items can be changed within OrcaFlex and so likewise should be editable from a batch script. However, in 9.2a the act of changing any such data item from a batch script resulted in the simulation being reset.
There were two separate bugs relating to range graphs with vertical arc length axis (a new feature introduced in 9.2a). Such graphs were reporting incorrect values in the hint window. Additionally, instantaneous value range graphs with vertical arc length axis were not automatically ranging themselves correctly.
Import of AQWA QTF data was failing if the data has directions which are split across more than one table.
Cancelling certain operations (e.g. opening a graph) could leave the program in a state in which simulations could not be run.

New in Version 9.2a

Implicit integration

The matrix solvers used by OrcaFlex have been updated. The new solvers are faster and more robust than those used in previous versions. For many models the impact of this change will be negligible. However, for more complex models with a lot of nodes then the new solvers can result in much quicker convergence and consequently shorter run times.
The default dynamics convergence tolerance has been increased from 1e-6 to 25e-6. Using the new default value results in shorter run times. We have performed extensive sensitivity studies and are confident that there is no loss of accuracy associated with this change.
The high frequency dissipation parameter for implicit integration has been removed and the program now uses a built-in value of 0.4.

Fatigue

Fatigue calculations have been significantly optimised resulting in vastly improved performance. Note that to take full advantage of these improvements the simulation files used by the fatigue calculation must have been generated by version 9.2. In addition the calculation now makes use of any available processor cores by processing load cases concurrently. These changes combined can result in calculation times 10-100 times shorter than previous versions, depending on the particular case and on how many processor cores are available.
The fatigue calculation performance optimisations described above now mean that the calculation time is often limited by disk access. Consequently it is important that the disk access speed is as fast as possible. Usually this means that the simulation files should be stored on a local disk of the machine performing the fatigue calculation.
A new method for damage calculation has been implemented based on stress factors. With this method stress is defined to be a linear combination of tension and curvature. This method is most suitable for fatigue analysis of umbilicals.
The damage calculation method used by older versions of OrcaFlex has been retained and is called homogeneous pipe stresses. Older versions of OrcaFlex calculated CC Stress, RR Stress and ZZ Stress, together with off-diagonal stress and von Mises stress at both inner and outer fibres. For the systems that OrcaFlex is used to model, damage is always dominated by ZZ Stress at the outer fibre. In order to simplify the program and speed-up fatigue calculations OrcaFlex now only calculates damage for ZZ Stress at the outer fibre.
A thickness correction factor has been added when you are using the homogeneous pipe stresses option. This factor is applied in addition to the SCF.
The fatigue results presentation has been significantly enhanced. The program now offers range graphs of fatigue. The program now saves fatigue results in the .ftg file which allows you to load and view results very quickly without having to repeat the calculation. Finally a number of new tables and other improvements have been made to the tabular results output.

Batch processing

The batch processing facility now makes use of any available processor cores by running jobs concurrently.

Lines

A new category of Line Type is now available: Homogeneous Pipe. This allows material properties to be specified by Young's modulus, material density and pipe diameters. This facility is appropriate for a pipe constructed from a single homogeneous material, for example a metal riser, or for modelling stress joints and bend stiffeners. The traditional method for specifying line properties is available as the General category of Line Type.
Line Type outer diameter can now be defined to be profiled – that is the outer diameter can vary with arc length. This facility is intended for use when modelling stress joints and bend stiffeners. In previous versions of OrcaFlex a profiled section of line (a stress joint or a bend stiffener, say) had to be modelled with a separate line type for each discretised segment of the profile. The new facility essentially automates the discretisation of the profile. Profiled line types are only available for homogeneous pipes.
OrcaFlex can now model wake interference. Three forms of wake model are available. The Huse model is the most widely used but only includes the drag reduction effect for downstream lines. The Blevins model extends the Huse model by modelling the wake lift force that tends to draw the downstream line into the centre of the wake. Finally you can use a user-specified model by providing drag and lift coefficient factors as a function of the position of the downstream line relative to the wake of the upstream line. A number of new results variables have been added to help understand the behaviour of these models.
The orientation and direction of range graphs axes can now be customised. This is particularly useful for vertical risers when it is often helpful to have the arc length axis vertical to match the physical geometry of the riser.
Seabed Normal Penetration/D and Seabed Normal Resistance/D results variables have been added. The Seabed Reaction Force result has been renamed Seabed Normal Resistance.
Strain results have been modified. Mean Axial Strain has been replaced with Direct Tensile Strain. This has also been redefined and now excludes the Poisson effect axial strain due to radial and circumferential strains caused by internal and external pressure. This change has been made to achieve self-consistency with the Direct Tensile Stress result. If you are modelling a homogeneous pipe then these results are now related by the expected equation E = s/e. Likewise we have redefined ZZ Strain to exclude the Poisson effect axial strain and this result now matches its corresponding stress, ZZ Stress. Finally we have replaced Max Axial Strain with Worst ZZ Strain which is the value of ZZ Strain with the greatest absolute value.
Drag coefficient results now include the in-line drag amplification factor if you are using this feature of the wake oscillator VIV models.

Vessels

The default Vessel Type had an inconsistency in the hydrostatic stiffness data. The default equilibrium position has been changed to match the reference origin, so with initial position Z = 0 the default vessel is in static equilibrium.
Vessel QTFs can now be specified for all 6 degrees of freedom.
Added mass and damping data can now be imported from text files in any format. You do need to add special mark-up strings to the files so that OrcaFlex knows which data to add. We provide instructions and examples for import from Moses, Ariane/Hydrostar and WADAM but import is possible from other programs too.
A number of vessel load results have been added and others have been renamed. Connection forces are now available in global axis directions as well as local. And, for both results tables and time histories, all the loads acting on vessels are now reported, and the reported total vessel load is equal to the sum of the reported constituent loads.
Non dimensional RAOs can now be specified as either deg/deg or rad/rad. Although these are equivalent we are hoping it may remove some confusion.

6D Buoys

6D Buoys can now be connected to other 6D Buoys which allows you to treat multiple 6D Buoys as a single rigid body. This can be particularly useful when you wish to model more complex shapes than the stacks of co-axial cylinders that Spar Buoys and Towed Fish allow.
A new azimuth results variable has been added for 6D Buoys.

General and Environment data

Random waves can now optionally include a directional spreading spectrum. This allows you to spread the spectral energy around the principal wave direction and can sometimes result in a useful reduction in conservatism.
Wave trains now have a wave origin data item which allows you to shift a wave spatially. This new data item is in addition to the wave time origin.
Previous versions restricted the number of dynamic stages in a simulation to 40. The limit has now been increased to 1000 stages.

Time history files

Time history files can now be sub-sampled using the Minimum time sample interval data item. This can be a very effective way to smooth time history files if the data quality is poor.
The interface for setting time history file data has been significantly overhauled. The Import Wizard used in previous versions has been removed and the data is now set entirely on the object data form. This makes it easier to check and also allows the data to be set through batch script. In addition the program now plots preview graphs of the time history data.

Results

Linked statistic results now report mean up-crossing period.
The Line clashing report now outputs contact velocity for each clash event.

User interface

Default workspaces can now be defined for individual files in addition to being defined for directories.
Context sensitive help is now available for the Variable list box on the Select Results form. Definitions of results variables can be obtained by selecting them in the Variable list box and then pressing F1.
3D View and Graph windows can now be exported as PNG files. These are essentially compressed bitmap files and are generally to be preferred over bitmap files.
Spreadsheet windows can now export in comma separated CSV format.
Files can now be submitted to Distributed OrcaFlex directly from the File menu.

Shaded drawing

Shaded drawing files are now specified in a slightly different way. In previous versions of OrcaFlex you had to specify a folder which contained a .x file with the same name as that folder. This rather limiting restriction has been lifted by allowing you to specify the .x file name rather than the folder name.
We have included an extra sample shaded model, an FPSO. This is essentially the same as the turret moored FPSO that we supply, but with the turret removed.

Automation

The Clear Sheet instruction in the OrcaFlex spreadsheet has been renamed Clear. It now allows you to clear either the entire sheet, or just a specified range.
The range graph instructions in the OrcaFlex spreadsheet now allow you to specify which curves are to be output. This can be useful if you, say, only want the maximum values to be reported.

OrcaFlex Programming Interface

We now provide an interface to OrcaFlex from the Python programming language. Python is a modern dynamically typed language that is very much easier to use than the programming languages traditionally used to interface to OrcaFlex (C/C++, Delphi). Despite being easy to use Python is still a very powerful language. We now recommend Python for the majority of OrcaFlex programming tasks and it is especially suited to scripting and automation of pre- and post-processing.
C_GetThreadCount and C_SetThreadCount have been replaced by C_GetModelThreadCount and C_SetModelThreadCount. The old functions continue to work but new code should use the new functions.
New functions for range graphs (C_GetRangeGraph4 and C_GetRangeGraphNumOfPoints2) have been added which allow an arc length range to be specified.

For full details please refer to the OrcFxAPI documentation.

Bug fix

Very large simulation files (greater 8GB) were loaded incorrectly in earlier versions. This problem has now been corrected.