OrcaFlex 8.0

The latest release of OrcaFlex 8.0 is OrcaFlex 8.0e. To upgrade to OrcaFlex 8.0e, download the following zip file:
OrcaFlex-Patch-8.0a-or-8.0b-to-8.0e.zip (1.3 MB)
and then run the program that the zip file contains.

This patch can only be applied if you are currently using 8.0a or 8.0b.

The new features introduced in OrcaFlex 8.0 are described below. For full details please download the following zip file: FlexHelp.zip (712 KB) and save the files it contains. You can then open the saved .hlp file and open the What's New topic in the Introduction chapter of the contents, and follow the links from there to other parts of the help file.

New in Version 8.0e (released November 2002)

Bug fix

There was a bug which affected the drag calculation for 6D Buoys which are slaves of Lines or Vessels. Such buoys can arise in a model in 2 ways:

A 6D Buoy's connection is set to be a Line or a Vessel.
A Line has an attachment where the Attachment Type is a 6D Buoy.

The drag force is calculated using the relative velocity of the fluid - that is the velocity of the fluid minus the velocity of the buoy. The bug is that OrcaFlex is calculating the drag using relative velocity based on the translational velocity of the buoy in the static state, rather than using the instantaneous buoy velocity. Changes in buoy velocity during the simulation are therefore not correctly contributing to the drag force. For more details contact Orcina.

New in Version 8.0d (released November 2002)

Statics

Statics convergence for some complicated models has been improved.

New in Version 8.0c (released October 2002)

Bug fix

The OrcFxAPI functions C_GetStaticResult, C_GetStaticResult2, C_GetTimeHistory and C_GetTimeHistory2 were not working for statics-only OrcaFlex.

New in OrcaFlex 8.0b (released June 2002)

Bug fixes

Multiple Statics was not accessible in version 8.0a (the multiple statics command wrongly did an ordinary static analysis instead).
Replays that had more than 32767 frames did not work correctly in previous versions.
Dragging and dropping a file onto OrcaFlex is no longer allowed during a statics calculation or when a simulation is active. Version 8.0a accepted the drag and drop but failed to open the file correctly.

New in OrcaFlex 8.0a (released May 2002)

Lines

Axial stiffness, Bend stiffness and Connection stiffness can all now be non-linear, by specifying variable data.
Drag coefficients can now vary with Reynolds number. Also, the drag coefficients and Reynolds number are now available as results for lines.
Line clashing can now include damping. See the new Contact Damping data item on the line types form.
We have changed the way the polar coordinates on the Line Ends form work.
There are new pop-up menu links between the line data form and the line ends data form.
The modal analysis now handles lines where seabed friction is present. However note that an approximation is involved.
The Line Type Wizard can now be opened when not in reset state, e.g. during or after a simulation, but only to view the Wizard data (to edit data you still need to reset first).

Vessels

Vessel primary motion can now be specified using a time history file.
The vessel results variables Mean X, Mean Y and Mean Z have been renamed Primary X, Primary Y and Primary Z, since they report the primary motion of the vessel. Old result spreadsheets containing the old names will still work correctly.
Previously, if a vessel's motion was specified using a time history file then OrcaFlex only smoothed the transition from static state to time history motion if the model's starting velocity was zero. Because of this a snatch could occur at the start of the simulation if the starting velocity was non-zero. To avoid this OrcaFlex now smooths the transition from static state to time history motion in all cases.
When importing wave drift coefficients from an NMIWAVE format file, the wave headings are now automatically converted to OrcaFlex convention.

Shapes

Objects now ignore any trapped water shapes which are connected to that particular object. See trapped water shapes for details.

Environment

New data items have been added for the temperature and kinematic viscosity of the water. These data items can be constant or variable. The temperature units can be specified on the general data form.
The seabed can no longer be specified as being rigid, i.e. have a seabed stiffness of '~'. To model a very hard seabed you can use a high seabed stiffness value, but remember that this may require a shorter simulation inner time step.
The wind direction can now be drawn on 3D Views. Also the user can now specify the drawing data for the following: wind direction, secondary wave direction, seabed profile, clump types.

General

The model title on the general data form, which was previously limited to a maximum of 60 characters, can now accept free format multi-line text and has been renamed Comments.
The units data can now be set in a batch script file and through the programming interface.
The 'Use Static Positions' button on the general data form has been renamed 'Use Calculated Positions' since it has been extended to work with dynamics.
OrcaFlex can now handle simulation files larger than 2Gb.
The manual is now available in Acrobat pdf format on the OrcaFlex CD. See CD:\OrcaFlex\OrcaFlex.pdf.

Interface

There is a new Locate facility on the model browser, to help you find an object in the current 3D view.
The keyboard shortcuts for the model browser have changed. F2 still opens the browser, but when the browser is already open F2 now allows you to edit edit the name of the currently selected object (previously F2 closed the browser). The model browser can be closed by pressing ESC or ALT+F4 when it has the focus. See keyboard shortcuts for details.
There are new keyboard shortcuts for filling blocks of cells when editing data.
More accelerator keys (the underscored characters on forms) have been added to make OrcaFlex easier to drive using the keyboard. For example you can now use key presses to change between different tabs on a form.
You can now open an OrcaFlex file by dragging and dropping it onto the OrcaFlex window.
You can now open a new file when a simulation is active. You are reminded that the model will be reset and given the opportunity to cancel.
OrcaFlex no longer warns when you are saving files with long object names. There is a new menu item which allows you to truncate long object names.
There is a new facility to compare two OrcaFlex files and display the data differences.
OrcaFlex now handles relative paths in a more convenient way.
Locking an object now protects you from accidentally changing which object it is connected to. Previously locking only prevented accidental dragging, not accidental connection changes.
When running a batch job, if you click the Stop button you are now offered the option of saving or discarding the partially run simulation.
When entering data you can no longer use thousands separators. E.g. 5000 can no longer be entered as 5,000 (where the comma character is the thousands separator on your machine).

Results

You can now view the empirical cumulative distribution for any time history graph.
Range graph and offset graph variables can now be multi-selected on the results form.
You can now ask the results form to 'keep open', so that several different results can be selected and displayed without having to reopen the results form repeatedly.
Results (graphs, tables etc.) are now labelled with the time and date when the simulation file was last modified. Previously the label gave the time and date when the output was generated.

Fatigue Analysis

The fatigue analysis form now has a Graph button to display the S-N curve.

Documentation Error

The documentation of how wall tension is calculated was incorrect. The pressure effects on wall tension are calculated using the stress diameters, not the buoyancy diameters. And the tensile stress loading factor is applied when calculating the wall tension.

Bug Fixes

In OrcaFlex 7.5a the wave View Profile and wind View Profile commands displayed values as a function of simulation time. This was not intended and was inconsistent with previous versions and with the wave List Events command, which reported global times. These View Profile commands have therefore been changed to report global times.
In OrcaFlex 7.5a to 7.5c, vessel type data printing, exporting and copying did not always work correctly (data items were sometimes overlaid by other data items).
In OrcaFlex 7.5c and earlier, importing RAOs did not work correctly if the decimal point separator was set to the comma character.
OrcaFlex 7.5a and 7.5b would not accept the value 'Infinity' (e.g. for the long wave period limit) when importing RAO text files.
When opening a simulation file that uses a time history file, if any data errors are found in the file then OrcaFlex now correctly reports the error. Previous versions abandoned opening the file but without giving any error message.
In OrcaFlex 7.5a to 7.5e, very steep Stokes' 5^th waves in very deep water sometimes caused floating point overflows.
In previous versions some end force results (End Force Azimuth & Declination and global end force) were sometimes wrongly reported as zero if the line end was free or released.