Orcina news

Continuing our series of posts on upcoming developments for version 10.2, we now move to an important enhancement to modal analysis. This development has aspects in common with another new feature, line statics policy, which we have discussed in an earlier post.

OrcaFlex modal analysis calculates modes for individual lines or for the entire system. The individual line option is commonly used to generate mode shapes for use in an external VIV analysis program like SHEAR7 or VIVA. Modal analysis for an individual line is based on the assumption that the line end nodes are fixed, and the remaining nodes in the line have freedom. For many riser or umbilical configurations it is perfectly reasonable to use these modes in a VIV analysis. However, there are some systems for which this approach is not appropriate, and the new coupled object modal analysis feature is intended to addresses this limitation.

Continue reading “Upcoming in OrcaFlex 10.2: Coupled object modal analysis”

We have somewhat neglected our series of posts on upcoming developments for version 10.2 of late, mostly because we have been working flat out on some new features. In this post we will cover multi-level undo and redo in the user interface.

Continue reading “Upcoming in OrcaFlex 10.2: Undo”

Continuing our series of posts on upcoming developments for version 10.2, we look at some enhancements to static analysis.

Version 10.0 relaxed the rules for connecting objects together, one aspect of which was allowing lines to be connected to other lines. This new flexibility had a number of consequences for static analysis of lines. In version 10.0, these consequences were dealt with in a very simple manner and in many situations that approach worked perfectly adequately. However, some models that took advantage of more general connectivity proved difficult to handle in static analysis. In version 10.2 we have introduced some new functionality to address these issues.

Continue reading “Upcoming in OrcaFlex 10.2: Line statics policy”

Continuing our series of posts on upcoming developments for version 10.2, we will take a look at a relatively simple, yet frequently requested enhancement to model building.

Complex structures are often modelled in OrcaFlex using multiple objects that are connected together. A common example would be a manifold modelled using a combination of lumped buoys and single segment lines, all connected together so as to move as one rigid object. When building such a model, there is plenty of scope for error. For instance, it is easy to forget to account for some part of the structure, or equally to double count parts of the structure. A common way to detect such mistakes is to calculate the combined mass, volume, centre of mass, centre of volume, etc. and compare with known values.

Previously, OrcaFlex did not offer any functionality to calculate these compound properties, but version 10.2 will address that.

Continue reading “Upcoming in OrcaFlex 10.2: Compound properties report”

We have just released Distributed OrcaFlex 6.0a which you can download from the Distributed OrcaFlex web page.

The significant change introduced in this release is the ability to run more than one Distributed OrcaFlex (DOF) Client process on the same computer. The motivation for the change is to support machines with very large numbers of processors. Machines with more than 64 processors have the processors split into processor groups. Each DOF Client can only use processors from a single group. For previous versions, there was a single DOF Client process per machine and so that process could only use processors from a single group. Allowing multiple DOF Client processes on a single machine enables full use of the processing capacity of that machine.

As well as the issue of processor groups, machines with large numbers of processors usually use NUMA memory architecture. In order to make the best use of such machines, programs need to make sure that memory is allocated on the NUMA node which contains the processors that use that memory.

Continue reading “Distributed OrcaFlex 6.0a released”

Continuing our series of posts on upcoming developments for version 10.2, we will now turn to some functionality entirely outside of the program, namely the documentation. OrcaFlex is an ever growing program, and as it grows, so too does the documentation. For version 10.2, we decided to make a number of significant changes to the documentation, especially in how mathematical formulae are presented.

Continue reading “Upcoming in OrcaFlex 10.2: Documentation”

As mentioned in a recent post here, we are going to publish a series of articles introducing some of the new features being developed for release in version 10.2. This article is the first of that series, discussing a new vessel option that allows users to make a choice between two methods for the interpretation of diffraction analysis data.

Continue reading “Upcoming in OrcaFlex 10.2: Vessel calculation mode”

Mooring line fatigue damage normally considers only tension load cycles. However, sometimes the mooring chain immediately adjacent to the fairlead (the ‘Top Chain’) can experience significant in-plane and out-of-plane bending which causes additional fatigue damage.

BV guidance note Fatigue of Top Chain of Mooring Lines due to In-plane and Out-of-plane Bendings, [NI 604 DT R00 E, Aug-14], (‘BV note’) describes a Top Chain fatigue damage assessment procedure which includes both tension and bending. Here we describe how to derive the necessary OrcaFlex results to use with the procedure outlined in the BV note.

Continue reading “Mooring Chain Bending Fatigue (following Bureau Veritas Guidance Note NI 604 DT R00 E)”

In the past we have not been very expansive about our development plans for OrcaFlex – usually nothing more than a short bullet list on our website. We’d like to engage more with our users about upcoming OrcaFlex developments. This post is intended to kick-start us in that direction.

But before we get into the details, here are some points that might be useful background:

• For roughly the last 10 years OrcaFlex has been released annually, usually around September or October.
• The latest release of OrcaFlex is 10.1c. Version 10.1a was released in October 2016.
• The version number denotes the major release – 10.1 is the current major release, 10.2 will be the next major release.
• Each version number has a minor revision letter with a marking the first minor revision, b indicating the second minor revision, etc.
• Minor revisions are intended to fix bugs rather than introduce major new functionality.
• Our website details OrcaFlex releases since version 9.5 in 2011.
• We also occasionally remove functionality – usually when we believe this is not being used.

In terms of individual functionality changes (both additions and removals), our software team plan to blog more about these on other occasions. This post summarises our planning process and states where we are currently with our plans for version 10.2 and beyond.

Continue reading “OrcaFlex Development plans for 10.2 and beyond”

OrcaFlex is primarily used in the offshore oil and gas industry, typically for installation analysis and in-place design of riser and mooring systems, pipelay analysis, field construction, etc., as well as being widely used in the oceanographic community. However, OrcaFlex is an extremely versatile package, and over the years we have seen it used for the global dynamic analysis of a wide variety of applications. Starting what will be an occasional series of blog postings about less common applications for OrcaFlex, we kick-off with a summary of these.

Continue reading “Less Common Applications for OrcaFlex”