Orcina news

Here you will find the latest news on the development of OrcaFlex. Alongside our LinkedIn page, it is a valuable source of information about what we are up to!

New diffraction example

A new example is now available on our website: L03 Semi-sub multibody analysis. This example focusses on a semi-sub platform that closely resembles the OC4 platform, as modelled in example L02.

In the L02 example, we assume the platform is a single rigid body. In the L03 example, we are interested in the loads acting through the connecting members. Consequently, we have divided the platform into four distinct floating bodies and used OrcaWave to run a multibody diffraction analysis. In OrcaFlex, the four vessel objects are connected via line objects with structural properties that represent the cross bracings and pontoons. Further details can be found in the accompanying PDF description document.

Please note that example L03 takes advantage of recent developments to improve the workflow when defining external stiffness for multibody analyses. Therefore, this example is intended for use with OrcaWave and OrcaFlex version 11.4 onward.

In version 11.4 we also developed OrcaWave and OrcaFlex to be capable of undertaking multibody analyses for objects consisting of multiple sectional bodies. This new feature is not considered as part of this example, although we hope to develop an example that will demonstrate this feature in the future.

We hope that you will find this latest example helpful and informative.

L03 Semi-sub

OrcaFlex 11.4 released

We are very pleased to announce the release of OrcaFlex version 11.4. The software was finalised and built on 22nd November. All clients with up-to-date MUS contracts will receive, in the week starting 27th November, an e-mail with instructions on how to download and install the new version.

Version 11.4 introduces much new functionality, including:



These are the most significant developments, in our opinion. As always there are more enhancements that are not listed here. All new features are fully documented in the what’s new topics:

Continue reading “OrcaFlex 11.4 released”

Correction to L02 OC4 semi-sub example

We have recently identified an issue with the L02 OC4 semi-sub example, where incorrect linear damping coefficients were used as input to the semi-submersible model.

To explain the problem, the original damping coefficients were referenced from a comparison study against tank test results, documented as part of the Offshore Code Collaboration study OC6 project – Phase I. The coefficients were then calibrated in OrcaFlex, through a series of free-decay tests. Those tests used damping coefficients with force units of newtons (N), however, the example models uses units of kilonewtons (kN). This difference in units was not accounted for as part of the model building process, which led to the transfer of incorrect coefficients to the ‘Other damping’ page of the OrcaFlex vessel type data form.

In light of this mistake, the supporting OrcaWave and OrcaFlex models have been corrected, and the latest version of the example is now available for download from the usual L Diffraction examples page of the Orcina website. For clarity, the correct coefficients are shown below:

Corrected linear damping coefficients for the L02 OC4 semi-sub example

This serves as an important reminder that the available published Orcina examples are intended for illustrative purposes, meaning they should be checked for accuracy and modified appropriately to suit the individual needs of an application or project.

We apologise to anyone who might have been inconvenienced by this oversight. Should you need any further clarification, then please do contact us for further details.

OrcaFlex 11.4 user group meetings

Following the release of OrcaFlex 11.4, we can now announce our OrcaFlex 11.4 user group meetings. Once again, we are running these as virtual webinars.

These webinars will cover all the new features introduced in version 11.4 of OrcaFlex and OrcaWave. We will split the content into two separate webinars, one for OrcaFlex and one for OrcaWave. Each webinar will be delivered twice in the same day to give users in different time zones the opportunity to attend.

We anticipate that each webinar will be around one hour in duration, and attendees will be able to ask questions. Recordings of the webinars will be available on our website shortly after they have taken place.

We are running the webinars over Zoom. You will need to register, using the links below, for whichever webinars you wish to attend, using the links below. Zoom webinars can be attended using the Zoom client, or directly from the browser if you do not have the Zoom client.

We look forward to catching up with our regular user group attendees, and hopefully some first timers too!

OrcaFlex new features

This webinar will introduce the new features in OrcaFlex.

12th December 2023
0900 GMT
12th December 2023
1700 GMT

OrcaWave new features

This webinar will introduce the new features in OrcaWave, our diffraction analysis program

14th December 2023
0900 GMT
14th December 2023
1700 GMT

OrcaFlex 11.3g released

We have just released a minor upgrade to OrcaFlex, version 11.3g. Version 11.3g fixes a number of bugs and adds some minor functionality, including:

  • Support has been added for SHEAR7 version 4.12.
  • Python external functions, post calculation actions and user defined results now support the latest version of Python, version 3.12.

Full details of the changes are described in the documentation:

We intend for this to be the final release of 11.3 because version 11.4 will be released later this month.

Distributed OrcaFlex 8.0a released

We have just released Distributed OrcaFlex 8.0a which you can download from the Distributed OrcaFlex page.

This is a major update containing the following changes:

New job list views

There are now two tabs to view the list of jobs with different perspectives:


The active list displays only the running or waiting jobs, the the same order as the job list in previous versions. However, it has a simplified interface for a quick overview.


Batches of submitted jobs are now grouped together under the detailed tab. In this view, more information can be seen about particular jobs, and the order of jobs remains constant (sorted by age).

Batch actions

The new job list structure allows for actions that can be performed on a whole batch at once:

  • Resubmit batch
  • Cancel batch
  • Pause batch
  • Resume batch

High DPI

The UI elements of Distributed OrcaFlex now scale cleanly at any resolution, improving use with high DPI displays.

Status icons

Icons have been added to the job status for readabilty, doubling as a summary of the job list in the status bar.

Proxy client

Previously, each DOF client process on a large machine would communicate individually with the DOF server. To reduce the amount of network traffic, an extra client process is created as a proxy, which collates the messages sent from and recieved by each subprocess.

File operations throttle

In place of the ramping feature, a throttle on the total saving and loading of jobs can be set to reduce the strain on the file server. If the total file operations exceed a certain threshold, the clients will delay the file read and writes by a random interval.

Batch notifications

Users can now be notified when an submitted batch has completed.

Update to wind turbine controller examples

We have recently made some updates to our set of wind turbine controller examples, which is now available to download from the new Orcina GitHub page.

The main change is the addition of a native controller wrapper example. This takes the form of a C++ DLL, having the same functionality as the existing Python wrapper. The reason for creating this example is to avoid restrictions imposed by the Global Interpreter Lock (GIL). The GIL is an inherent part of the Python process, and it can be restrictive if using Python (e.g. external functions) whilst using multi-threading to run simulations in parallel.

For example, the OrcaFlex batch processing tool uses multi-threading to run a batch of simulations, but there is only one GIL which acts as a gatekeeper for that process. For any models using Python, this can cause performance bottlenecks when running many simulations in parallel.

As the GIL is inherent to Python, running the simulations using the native (C++) wrapper avoids this restriction altogether. In turn, this has the potential to lead to improved efficiency when running large multi-threaded batches of simulations.

Although the native variant has the benefit of avoiding the GIL, the Python variant still has value. It’s easy to modify if adjustments need to be made, for example if you need to adjust what is passed to and from the swap array. This can still be done for the native variant, but the process is more difficult because it requires modification of the C++ source code and then recompilation of the DLL.

For this reason the C++ source code – used as a basis for the native DLL – can be downloaded from the same GitHub page mentioned above: see the folder Bladed controller wrapper\Native controller\src. The build folder contains both a Microsoft Visual Studio project and a MSYS2 makefile, either of which can be used to compile the DLL. This caters for two common C++ toolchains.

We have also made a couple of other minor adjustments to make the Python and native variants have feature parity. The notable changes are:

  • Minor changes to how the Python controller wrapper models are set up. Instead of having separate classes named PitchController and TorqueController, there is now a single class named BladedController.
  • The yaw controller example – offered in earlier revisions of this resource – has been removed for now. We hope to replace this with a new example in the future. In the meantime, the old example can be supplied upon request. Please contact us for further details.

For further details about the latest updates, please see the Bladed controller wrapper section of the accompanying PDF document. Note, the Code drop-down box, at the top of the GitHub page, provides the option to download this entire resource as a zip file.

Wind turbine examples

Lastly, to reflect the latest set of controller examples, the K02 and K03 examples now demonstrate the implementation of the Python wrapper and native wrapper respectively. A summary of the model setup is provided in the Controller modelling section of the PDF description included with each example.

We hope that you will find the latest updates helpful. We always welcome any questions or feedback, so please do contact us for any further enquiries.

OrcaWave – working with meshes

We have recently uploaded a new technical note to our website titled OrcaWave – working with meshes. The document focuses on the use of panel meshes in our diffraction analysis tool OrcaWave. We describe the link between mesh refinement and results quality. Furthermore we discuss how features such as symmetry conditions, calculation method and meshing technique can be used to report converged results whilst reducing run time and memory requirement.


This new resource can be found alongside a range of existing technical notes on the Papers and technical notes page of our website.

OrcaFlex 11.3f released

We have just released a minor upgrade to OrcaFlex, version 11.3f. Version 11.3f fixes a number of bugs, and makes further performance improvements for processing of multiple jobs on machines with large numbers of processors.

Full details of the changes are described in the documentation:

We recommend that all users of 11.3 upgrade to 11.3f.

To upgrade to OrcaFlex 11.3f from any previous version, download the install program from your company’s Orcina software download page. A link to this page was sent to your software administration contact when we released 11.3a. If you do not have access to this page, please contact us.

OrcaFlex 11.3e released

We have just released a minor upgrade to OrcaFlex, version 11.3e. Version 11.3e fixes a number of bugs, and addresses a performance issue for batch processing of multiple jobs on machines with large numbers of processors.

Full details of the changes are described in the documentation:

We recommend that all users of 11.3 upgrade to 11.3e.

To upgrade to OrcaFlex 11.3e from any previous version, download the install program from your company’s Orcina software download page. A link to this page was sent to your software administration contact when we released 11.3a. If you do not have access to this page, please contact us.