Tag: dynamic analysis

ProteusDS v2.36 is now available

Posted on July 4, 2017
Lauren Dunn

DSA is very pleased to announce the release of ProteusDS v2.36. The software is ready to go and active subscribers can use their login credentials to download the latest version from our website. We’ve highlighted some of the key new features below.

Support for visualization-only models

A good computational model is very different than a 3D model used for purely visualization purposes. Because of this, we have added the ability to handle models that are to be used for visualization purposes only. Now, in the ProteusDS Simulation Toolbox, you can add a $VisualizationModel property to a RigidBody. The model specified through this property is not used for computations. We have added functionality in both PostPDS and ProteusDS Simulation Toolbox to toggle visualization or computational models on or off.

Image of Blended copmutational vs visualization labels

Comparing computational and visualization display modes in PostPDS

Bathymetry analysis

We have released a set of powerful bathymetry analysis features in PostPDS that allow users to assess seabed slope and depth. To access these features, simply right-click on the Seabed item in the Categories tree in the UI, and select the appropriate Bathymetry Plotting option. The depth and slope plots now have legends that make it easy to interpret seabed data. The exclusion zone plot allows you to find safe regions to place equipment or position anchors.

PostPDS showing the slopes in a bathymetry file using the bathymetry plotting options

Modeling ropes that are sewn into nets

For our aquaculture and net-modeling users, we have added support for modeling rib-lines or “structural lines” that are frequently sewn into nets to add strength and shape. This is done within the Net DObject itself and not using additional Cable DObjects. This dramatically reduces the numbers of DObjects and connections required to simulate a net pen with rib lines leading to faster simulations. To apply a rib-line to a net, use the $ExtCableLongitudinal or $ExtCableTransverse property in the Net input file.

We have also added an option to connect the end of a line to any point on a net. You do not have to connect a line directly to a node! This is much easier for creating supporting lines in net pens. To create this connection specify the Net as the master and the Cable as the follower, and use the Point connection type.

Image of structural lines that are swen into net panels

Visualization of structural lines (indicated in yellow) that are sewn into net panels.This feature reduced net analysis complexity significantly.

So, that’s ProteusDS 2.36 – we hope you enjoy it and find the new features useful.

v2.36 Changelog

Additions:

Added time history plot functionality for RigidBody DObject in PostPDS
Added legends for bathymetry plots in PostPDS
Added support for computational and visualization models in ProteusDS solver, PST, and PostPDS
Added height above seabed probe to RigidBody to check for clearance
Added inclination angle and tension output for ExtMass and ExtMassCylinder attachments
Added ability to connect the end of a cable to anywhere on a net panel
Added ExtCable functionality to Net DObject to allow for modeling of ropes which are sewn into nets to provide strength and shape

Changes:

Enhanced ‘Duplicate Selected DObject(s)’ functionality to allow for optional duplication of connections

Resolved issues:

Addressed overlapping water rendering
Improved full-screen support with ability to toggle the display device that the full-screen window appears on by pressing ‘F1’
Addressed mooring line naming issue with taut leg mooring generator

View our 2015 changelog here

DSA Announces Reseller Agreement with OceanPixel

Posted on June 8, 2017
Lauren Dunn

OCEAN ENGINEERING COMPANY DSA ANNOUNCES REPRESENTATION FOR SOUTHEAST ASIA

Halifax, Nova Scotia – Dynamic Systems Analysis Ltd. (DSA) maker of ProteusDS dynamic analysis software is pleased to announce that it has signed an agreement with OceanPixel of Singapore and they will represent DSA and its software products in Southeast Asia.

DSA is an engineering services and software development company. ProteusDS is DSA’s flagship hydrodynamic and mechanical marine dynamic analysis software package. It is customizable, validated, efficient, and reduces the risk for its users by allowing them to assess how their technologies will respond to extreme wind, waves, and currents. ProteusDS is capable of enhancing in-house analysis, design, and system optimization capabilities for offshore, subsea, and marine organizations.

OceanPixel currently offers suitability analytics and other technical services for the marine renewables market, including engineering and environmental assessment. It is working on projects in Singapore, Indonesia, and the Philippines, and is pursuing projects all over Southeast Asia.

“OceanPixel is proud to have Dynamic Systems Analysis Ltd as a partner in advancing the marine renewable energy industry in Asia.” said Michael Lochinvar Abundo, Managing Director at OceanPixel. “Through this partnership, we hope to deliver a range of great quality services to various sectors involved in the Marine and Offshore industry.”

The collaboration between the two companies will enable delivery of turnkey solutions to the marine renewables market in Southeast Asia. OceanPixel will provide sales, training, and consulting services for DSA’s products in the market.

“We’re very excited about this partnership,” said Dean Steinke, Director of Operations at DSA. “Working within the marine renewables sector has always been a natural fit for us. The uniqueness of the marine renewable industry calls for constant innovation. It requires the provision of software and teams like OceanPixel’s that are extremely flexible and adaptable to the sector’s needs. OceanPixel will expand our presence in the increasingly important Southeast Asia marine renewable market. It’s an ideal partnership.”

About OceanPixel

OceanPixel Pte Ltd (OP) is a Singapore start-up company spun off from the Energy Research Institute at Nanyang Technological University (ERI@N) incorporated in September 2014. The core team has combined expertise in Renewable Energy research, development, demonstration, project development and know-how and experience in the relevant industry ecosystems, business, finance, policy and education.

Offering technical services, data catalogues and report products, we have various global involvements and currently handles projects in Singapore, Indonesia, and the Philippines with potential projects in other parts of Asia under development.

Strategically partnering and collaborating with experts from the UK and, with access to marine renewable energy thought leaders in the South East Asia (SEA) region, OP has positioned itself to be the pioneer company dedicated to ocean renewable energy planning and development in SEA and beyond.

For more information about OceanPixel http://www.oceanpixel.org

How to Solve 8 Tough Ocean Engineering Problems with Dynamic Analysis

Posted on March 31, 2017
Lauren Dunn

Many engineers think of dynamic analysis as being required for analyzing risers and moorings in the offshore industry. But dynamic analysis is used in many other marine sectors for alternative applications.

ProteusDS is DSA’s dynamic analysis software. It is used by ocean engineers and industry professionals to conduct a dynamic analysis of systems that are exposed to extreme wind, current and waves. There are many applications for the software outside of offshore oil & gas – so let’s explore just how diverse the software is…

Aquaculture

These systems include traditional fish farms in both circular and square cage designs along with shellfish aquaculture farms. These systems often contain nets which are connected to moored rigid or semi-rigid structures, such as buoys and floating collars.

As the aquaculture industry continues to grow, the number of traditional sheltered sites is declining, and thus an increasing number of installations are operating in regions that are exposed to high energy ocean swell, current, and wind conditions. The need to understand how to design aquaculture installations is necessary.

To support accurate aquaculture analysis, we have recently added wake-shielding and self-shielding models to ProteusDS, which is essential to avoid any overly conservative estimation in the loads on ﬁsh farms for installations.

Debris Impact & Cable Contact

ProteusDS has been recently enhanced to model contact between bodies. This technology could be used to predict the effects of ice or a log impacting a floating platform. Alternatively, lines running through a sheave or a chute can be modeled. This capability is under active development, and users interested in testing it should contact us.

Cable Ferry

ProteusDS is used by naval architecture firms to predict the motion of vessels and marine platforms. Used in conjunction with BEM software like DSA’s ShipMo3D, ProteusDS is used to perform seakeeping and manoeuvring studies. These studies can include moorings, towlines and cables.

ProteusDS was recently used to conduct an in-depth analysis of a cable ferry running between Vancouver Island and Denman Island in Western Canada. The ferry was modeled using a 6 DOF rigid body. The model developed captured key sources of loading, including wave diﬀraction and wind loading on the superstructure. The ferry travelled across the channel using a simulated traction winch that acted on the drive cable. The cables were modeled using the ﬁnite element cable model that also interacts with the bathymetry of the channel. The ultimate and fatigue loads in the cables were assessed using the model.

Commercial Fisheries

The ability to model winches, lines, vessels and nets allow for modeling many types of fishing operations. Through numerical modeling of commercial fishing operations, ProteusDS has been used to cut client’s’ costs by limiting snarls and providing feedback on optimal tow arrangements and winch selections. DSA has also generated informative 3D visualizations of the behaviour of fishing gear in the water and supervised flume tank testing of fishing gear.

Elastic Moorings

Elastic moorings are often used in situations where elongation or compliance is needed, but where a chain mooring is not practical or may harm the environment, or where space is limited. The Seaflex elastic mooring technology relies on a viscoelastic rubber hawser with specially formulated characteristics that is used to manage loads.

The load response of Seaflex depends on the time history of loading.This complex hysteretic phenomenon, while well understood from a conceptual standpoint, can be difficult to represent numerically. Seaflex and DSA worked together to solve this problem and accurately model the response of Seaflex mooring technology using nonlinear axial rigidity parameters. This nonlinear axial rigidity modeling capability is also useful for synthetic rope with nonlinear elongation characteristics – such as Nylon.

Towed Arrays & Towfish

ProteusDS can also be used to simulate towed systems such as towfish or towed arrays. For towfish, the foil model is used to model control surfaces. The control surfaces can be actively controlled to maintain depth or altitude. The tow cable and vessel dynamics can be incorporated to perform layback analysis.

Similarly, the high fidelity cubic finite-element cable model can be used to analyze the loading and profiles of high speed towed arrays for seismic or defence applications.

Launch & Recovery

Safely deploying and recovering equipment (spools, jumpers, AUVs, ROVs, small craft) from vessels in various sea conditions is a potentially high risk operation. Predicting the limits of safe launch and recovery operations in terms of human factors, loading and motions can enable operators to make good decisions in the field and prevent errors.

ProteusDS contains a mechanism modeling and control infrastructure that model A-frames, cranes, and other handling equipment. Offloading, lowering, and many other operations can be simulated. An important benefit of this type of analysis is that visualization of these simulations helps managers, analysts, and others better communicate with each other about how complicated operations will take place.

Tidal Device Installation

In many ocean sectors, sea trials or operator experience largely guide routine marine operations. However, in tidal energy, the strong directional currents and narrow deployment windows make it difficult to perform sea trials safely and cost-effectively, and there is often less operator experience. ProteusDS has the ability to perform fully coupled analysis of floating service vessels installing structures such as tidal turbines, floating platforms, or laying cable.

Modeling the waves and currents in tidal passages is important for these assessments. ProteusDS contains a spatially and time-varying current modeling capability that enables accurate representation of large-scale eddies and turbulence which will impact towing operations.

Designing for the ocean environment is a constant challenge. Dynamic analysis with ProteusDS allows for rapid innovation and optimization while reducing risk.

To learn more about DSA’s services, or licensing the ProteusDS software please feel free to:

ProteusDS v2.34 is now available

Posted on March 23, 2017
Lauren Dunn

v2.34 is now available

It’s been an exciting and busy start to 2017 here at DSA and it’s been several months since our last release of ProteusDS (v2.29) – so we are very pleased to announce the release of ProteusDS v2.34.

The software is ready to go and login credentials for active subscribers will allow you to access ProteusDS v2.34 from our website.

Version 2.34 introduces new functionality, including:

Net modeling enhancements

The latest version of ProteusDS contains fixes and enhancements for net modelers. Improvements have been made to increase the accuracy of predicted hydrodynamic forces on nets, and mooring components in the wakes of nets. The pre-existing wake-shielding model, which accounts for fluid velocity reduction through nets, has been updated and is considered essential for not over-estimating forces on successive net pens in simulations. This builds on the self-shielding model that was added in the previous release to account for local hydrodynamic shielding between adjacent net twines at low angles of incidence

Secondly, automatic adjustment of net twine drag coefficient with Reynolds number has been added as default to nets, and has been proven to accurately estimate hydrodynamic forces on nets over wide ranges of fluid velocity. DSA has produced a validation document which outlines the net model developments for estimating hydrodynamic loading and comparisons made to experimental tank tests of nets and full-scale fish farms. It is critical that net users add to their existing net model input models the $FluidCoefficientReData property.

Enhancements have also been made to the net arc space calculations in ProteusDS, which is used to position external masses on nets. Performance improvements were made by switching from a bi-quintic to a linear-cubic interpolation scheme.

The image shows a side view of three successive square aquaculture pens, with current flowing right to left. The leading cage experiences the largest hydrodynamic forcing and netting deformation. Current velocity is then reduced with the wake shielding model as the flow traverses through multiple nets, as seen in the middle and trailing cages.

Lastly, improvements have been made to previsualization of nets in the ProteusDS Simulation Toolbox. Users can now distinguish which net edge is which according to its colour.

Users can now distinguish which net edge is which according to its colour.

Cable model damping optimization

The finite-element cable model is one of the core models in ProteusDS. Users will now have the ability to automatically estimate a reasonable axial damping coefficient in cables based on a damping ratio, axial stiffness and element lengths. Testing has shown that this typically results in major simulation speed-ups.

Simulation execution time can be greatly increased by utilizing automatic cable damping, as each instance of a cable segment defined in a cable has a particular calculated axial damping coefficient based on the average element stiffness, average element length, and cable node mass covered by the cable segment.

Environmental condition transitions

The latest version of the ProteusDS contains a major new feature that allows control over the application current, wind and waves in a simulation. We’ve added the ability to independently control when the current, wind, and wave conditions will start in any given simulation and the length of time that those conditions will be ramped to their set state.

Previously the singular $TRamp property was used to control ramping of all environmental conditions. Users could not, for instance, have a steady state current with wind and then have waves start at some point later on in a simulation.

This feature is very useful when a user wants to determine an initial steady state configuration (positions and loads) for a model (e.g. a mooring system, a fish farm, a moored buoy) – then after the steady state is reached, introduce unsteady wave loads. Previously this level of analysis was only achievable after running separate simulations.

So, that’s ProteusDS 2.34 – we hope you enjoy it and find good use for all the new features.

Complete list of additions, changes and resolved issues.

Additions:

ProteusDS Simulation Toolbox pre-visualizer now displays name of any currently selected DObject(s)
Added Net edge and ribline colouring to pre-visualizer
Added automated calculation of axial damping for Cables/Scables using $AxialDampingMode property
Added environmental timing/ramping options to the Environment input file which allows users to set the start time and ramp duration independently for wind, waves and currents.
Improved 2.5D spatially varying current loading
Added Reynolds number dependent drag as default to net panel feature
Added defaults for variation of drag with Re (for cylinders)
Improved drag loading and wake/shielding model for nets
Improvements to simulation destabilization detection

Resolved issues:

Addressed a number of rendering issues in pre-visualizer
Improved performance of pre-visualizer rendering
Resolved out-of-bounds current sampling
Renamed “Transform” to “Translate / Rotate” in ProteusDS Simulation Toolbox

View our 2015 change log here

Tackling Tidal Energy with these Turbine Tricks

Posted on October 12, 2016
Lauren Dunn

What is the ProteusDS turbine feature and How Does It Work?

Extracting energy from the ocean’s tides is a challenging task. However, the amount of available energy and the predictability of the tides provides many incentives. The tidal energy industry is growing rapidly, especially in regions that possess strong tidal resources, such as the Bay of Fundy in Canada and Orkney in Scotland. In-stream tidal energy converters (TECs) are being developed to harness and withstand the forces in these extreme environments. Structural loads, mooring loads, and structure motions need to be well understood before deploying expensive equipment in such harsh environments. Accurate modelling the loads and motions of the TECs are required for the rapid and cost-effective design. Dynamic Systems Analysis has developed a turbine feature as part of the ProteusDS time domain dynamic analysis software package to help perform analysis on TEC devices.

Create, Optimize and Analyze

Daily, DSA’s engineers and software users work to create, optimize, and analyze virtual prototypes of equipment from moored barges to complex tidal turbine systems. While these two projects differ in many aspects, fundamentally the reason for performing the analysis is the same: reduce risk and uncertainty.

Virtual prototypes show the dynamic response caused by the effect of the wind, waves, and ocean currents. DSA’s easy to use software, ProteusDS, allows for quicker analysis, design iteration, and optimization, providing an accurate assessment of equipment and vessel behaviour under a variety of marine environmental conditions. The analysis reduces the need for physical prototypes and testing, saving both money and time.

TEC developers often complete advanced analysis, such as computational fluid dynamics (CFD) or model scale tests, on the turbine itself. Therefore, the thrust, torque, and power curves are already known before the rest of the TEC structure is fully designed. The turbine feature allows TEC developers to quickly input existing thrust and torque data on their turbines into the dynamic analysis tool. The turbine feature also incorporates the control scheme of the turbine that includes operational effects like feathering power or optimal efficiency. By applying these detailed effects of each turbine in the simulation model, developers can better understand the global response of the entire TEC system.

Understanding the Load

During turbine operation, turbine thrust loads can have the most significant effect on the system, so it is important to ensure they are accurate. The turbine feature allows for the thrust and torque coefficient to be dependent on the tip speed ratio (TSR), relative velocity, or both and contains a second order control system to allow for the turbine to accelerate realistically with changes to the relative fluid velocity. This feature pairs perfectly with the turbulence modelling available in ProteusDS. This feature also allows for the accurate effect of power shedding such as with flexible turbine blades or feathering blades so that as relative fluid speed increases, the thrust and torque coefficients decrease accordingly.

The turbine feature allows for several scheduled control modes. The user can set the turbine to apply a brake, freewheel, or return to operating mode at any time in the simulation. The user can also specify cut-in and cut-out speeds that will automatically brake the turbine if relative fluid velocity outside of these set-points is reached. These features allow TEC developers to model extreme cases that may trigger turbine shutdowns that will affect the behaviour of the entire structure.

The ability to view and understand how a system will react is a big advantage in any ocean industry, but especially so in fast flowing tidal channels. It allows you to plan ahead and gain insight into how a system will react to a wide range of conditions. Determining areas of potential problems will reduce project risk and provides assurance that the design can withstand the extreme ocean conditions.

Modelling tidal energy devices in unique environments are an important step in designing successful TECs, and few tools specific to the tidal industry are available. The turbine feature in ProteusDS allows for quick set-up of a TEC device or farm to help tidal developers perform a numerical analysis. ProteusDS can provide invaluable insight into structure loads, mooring loads, and system motion in varying environmental and operational conditions.