The Wolfson Unit would like to congratulate the project team of Kokomo upon winning the award for Best sailing superyacht over 40 metres at the recent International Superyacht Society awards in Fort Lauderdale.
The Unit carried out a series of model scale towing tank tests for Dubois Naval Architects Ltd to assist the designers in optimising the hydrodynamic performance of this 58 metre sloop.
The Unit has had a long association with the Dubois office, helping them develop hull and keel configurations to accommodate lifting keel and other effective appendages for these large sailing yachts. All this design development has created yachts with good sailing performance (near to race standard) and ease of handling, within design constraints such as moderate draught.
Images courtesy of Dubois Naval Architects Ltd and Chris Lewis
For more information on our yacht testing and performance prediction services please see our Yacht Testing page.
Heesen Yachts has unveiled the revolutionary 65-meter, all-aluminum design based on the Fast Displacement Hull Form (FDHF), whose tank testing has been completed at the Wolfson Unit in Southampton (UK). Developed by Dutch naval architects Van Oossanen & Associates, the Heesen 6500 FDHF is a truly innovative concept that increases the overall performance of the superyacht.
Tank tests have shown that in comparison with traditional hard chine and round bilge hulls, FDHF improves the efficiency of the vessel by around 30%. The slenderness and special form of the hull result in a very low wave profile over the entire speed range, while also improving its sea-keeping and maneuverability. As a consequence, it has a very positive impact on the cost of running the yacht, while also lowering its environmental impact in terms of engine emissions.
Heesen Yachts presented this innovative 65-meter design to the yachting community on September 22nd 2010 at the Monaco Yacht Show.
Images courtesy of Heesen Yachts and Van Oossanen & Associates bv
For more information on our range of services see our services page.
The 50m superyacht Exuma, is the first hull of the Vitruvius series, born from the collaboration between Vitruvius Ltd, Philippe Briand and the Perini Navi Group. The aluminium hull follows the principles of the Briand Optimized Stretched (BOS®) Hull and is characterized by streamlined, limited waterline length and a straight and deep bow.
Exuma has been awarded the GREEN Yacht of the Year award as well as the GREEN PLUS PLATINUM certificate in recognition for her proven commitment to environmental excellence. RINA’s GREEN PLUS notation is based on an environmental performance index, which covers all aspects of the vessel’s impact on the environment, including but not limited to carbon emissions.
From the outset of the design process, the owner, the architects, Philippe Briand, Vitruvius Yachts Ltd and the shipyard, Picchiotti, were determined to create and build the ultimate environmentally friendly explorer yacht.
The main contributing factor is the Briand optimized hull form. The hull has a stretched waterline length which has been extensively tank-tested by the Wolfson Unit. The hull has a reduced transom immersion and a plumb bow. The clean aft sections allow for easy flow on the propellers. The Vitruvius Picchiotti has notably balanced superstructure volumes resulting in further weight savings. She has a lower centre of gravity, resulting in less pitching and rolling, which minimizes added drag associated to ship motions.
Images courtesy of Vitruvius Ltd. and Philippe Briand Ltd.
For more information on our range of services see our services page.
We wished a happy retirement last week to Peter Weynberg, who has been a key member of the Wolfson Unit since 1971. After an early career at sea, as an officer on merchant vessels, he graduated in Nautical Studies in Southampton and joined the Wolfson Unit. In the early years he developed various computer programs and started the Unit’s bureau service for hydrostatic and stability calculations, which was in great demand in the 1970’s when computers were beyond the reach of most design offices. He also developed expertise in the experimental work that has always been central to the Unit’s work, and his understanding of electronics was invaluable in designing, building and maintaining much of the instrumentation used. He was a fundamental part of many of the large projects undertaken by the Unit, but because of his reluctance to write papers or seek credit, his name is not as well known in the industry as perhaps it should be. His natural ability for a clear analytical approach to problem solving will be greatly missed by his colleagues.
The leaving gift for the man who has everything he needs was a half model of the sail training ship Sir Winston Churchill, in which Peter sailed many voyages as navigator or mate, and on which he met his wife.
The Fraserburgh trawler “Virtuous”, designed by Ian Paton of S.C. McAllister, and built in Whitby by Parkol Marine Engineering, has completed its first fishing voyages and confirmed the fuel savings predicted from the Wolfson Unit’s model tests. The vessel is a twin-rig prawn trawler of 23 metres, and the fuel consumption reduction of around 20% compared to similar vessels will save the owners around £50,000 per year at today's fuel prices.
The owners asked the designer for a hull with fuel efficiency optimised when towing, which represents about 85% of the voyage cycle, and the ability to maintain speed when towing into heavy weather without a significant increase in power. Initial discussions were for a 21 metre vessel, but the Green Trawler project conducted by the Wolfson Unit for Promara revealed that dramatic fuel savings could be achieved with modest length increases. The tests also showed that seakeeping performance would be much improved, with greater comfort and less added resistance in waves, and this has been borne out by the first two voyages which included fishing in northerly gales. The vessel is longer and more slender than other modern vessels, with less curvature in the afterbody giving improved flow to the propeller.
The owners are delighted with the vessel and praise the designer and yard for delivering a vessel that met, and in some aspects exceeded, their specification. At the Wolfson Unit we are pleased to have been able to contribute to its development.
For more information on the Green Trawler project see:
THE DEVELOPMENT OF A “GREEN TRAWLER”
Dominic Rihan, Noel O’Regan and Barry Deakin
First International Symposium On Fishing Vessel Energy Efficiency ‘E-Fishing’, Vigo, Spain, May 2010.
The Wolfson Unit has released a demonstration version of HST Onboard, a stand-alone program designed for use by bridge personnel in order to compute vessel-specific sailing state, stability and longitudinal strength information in any loaded condition. Please follow this link or visit our software page to download the HST Onboard demo.
The program is supplied with data files, which define the vessel's geometric shape and loaded conditions, including capacity data for all of the tanks. HST Onboard enables the operator to:
Select and edit loaded condition information;
Verify the vessel’s compliance with intact stability requirements, as set in the Stability Booklet;
Show and print reports, which may be used as the ship’s official record at the time of departure.
HST Onboard uses the functionalities of HST (the Wolfson Unit's hydrostatics, stability and tank capacities program) and those of HST Loading (that calculates weights and centres, loading conditions, longitudinal strength, maximum KG and intact stability criteria). The program uses the hull definition from HST.
The analysis tools available to yacht designers are becoming more sophisticated and quicker and cheaper to run, what needs to develop in parallel with this is a software infrastructure that reduces the burden of communication between collaborating technical groups.
In developing the innovative WinDesign 6 VPP the aim has been three fold:
to provide extended functionality in terms of force and moment balance, component based force models, and improved geometry input;
to provide a platform that allows geometry and results to be exchanged securely and accurately among project collaborators;
to create a VPP frame work that can integrate with the wide range of experimental and Computational tools now available.
The WinDesign 6 Seminar at the University of Southampton on September 16th not only offers a preview of the WinDesign 6 VPP but also the development of the collaboration tool ‘Brio’ and the open source RANS CFD code ‘OpenFOAM’. WinDesign 6 has been developed to integrate seamlessly with these tools.
The second International Conference on Innovation in High Performance Sailing Yachts (INNOV’SAIL) took place in Lorient on 30th June-1st July 2010. Andy Claughton presented a paper on the prediction and optimisation of off wind sails, which attempted to draw together the latest experimental and computational techniques available to designers.
The conference did exactly what it said on the tin, practitioners from the world’s leading academic and research institutions explained their latest work on Computational Fluid Dynamics, physical model testing and fluid structure interaction methods. The papers all discussed applications to real design questions on the latest racing yachts.
Key themes:
Data management through the design, build and full scale testing process.
Developing the VPP to work with a wide variety of force data inputs, and the associated data handling issues.
Developments of hydrodynamic force models based on standard series tests.
Optimisation methods and neural networks/genetic algorithms to develop optimum design solutions.
Fluid structure interaction, sails on masts, water on hulls and hydrofoils, how to best calculate the influences of fluid force on a flexible structure, and vice versa. How can these tools be coupled with more and more accurate CFD solutions.
Improving the robustness and timeliness of high performance computing resources so they can become part of the everyday design process, not just preserve of AC teams.
Overall a very successful conference with nearly 150 attendees, inflated a little by the good deal for students. Stand by for an even bigger event in 2012 when the 3rd edition is scheduled to coincide with the Volvo stopover. In 2 years time there may be some problems looking for solutions, rather than the other way round.
Some Wolfson Unit clients have recently requested information on the use of Wolfson software on MAC machines. All Wolfson software is developed for Windows/PC but can run on a MAC if a Windows environment is made available through a virtualization tool such as the free Virtual Box program.
All Wolfson software has been tested on a MAC machine with MAC OS X 10.6 Leopard installed and Virtual Box 3.2.4 and the programs all appear to function correctly. Our trials were conducted using Windows 7 64-bit as a guest operating system.
The Wolfson Unit has obtained a digital Software Publisher Certificate (SPC) from a trusted Certification Authority, which has now been built into all our installations and executables in the form of a Microsoft Authenticode® digital signature. This ensures that the software downloaded from our website and the programs supplied in the Wolfson Software CD Rom actually come from us and have not been tampered with since their publication.
The digital signature of our programs can be inspected by right-clicking any Wolfson executable and then selecting Properties > Digital Signatures.
Our clients using Windows Vista and Windows 7 will notice that the warning messages issued by the operating system when installing or running our software have disappeared. Depending on the personal User Account Control settings, the operating system may now bring up a dialog (below) asking for permission to continue and showing a link to our Software Publisher Certificate.
The Wolfson Unit will be at NAVALIA, the International Shipbuilding and Maritime Industry Exhibition in Vigo from the 18th to 20th May.
We shall have a stand in the Research and Development area of the exhibition, and Barry Deakin will present the first paper of the e-fishing conference that will be held in the same building. This will be the 1st International Symposium on Fishing Vessel Energy Efficiency, and Barry will present a paper on ‘The Development of a Green Trawler’ in conjunction with Promara Ltd. and the Irish Sea Fisheries Board.
After the presentation the paper will be available on the published papers page of our website.
Barry Deakin attended the second Chesapeake Powerboat Symposium in Annapolis last week to deliver a presentation on recent developments in testing radio controlled models. The event saw a gathering of 130 delegates, representing several European and some Asian countries in addition to the inevitable majority from the USA. The symposium followed the highly successful format which has become familiar at the Chesapeake Sailing Yacht Symposium, which has been held every other year since 1974.
The papers and presentations were of a high technical standard, and delivered much valuable information from practitioners in the industry. Many conference proceedings comprise reports of incremental advances in academic research, but these are not a feature of the Chesapeake symposia.
For more information on our range of services see our services page.
Self propelled models under radio control have been used for many years to assess the manoeuvring and handling of ships. The limitations for testing small, fast craft have been linked to the low model weight required and the ability to install enough power, as well as the cost of modelling. Engineers at the Wolfson Unit have developed test methods appropriate for studying the particular problems of small craft, with small budgets, but model speed has always been limited by the available components.
Recent advances in motor and battery technology, the availability of model water jet drives, and developments in small data logging and GPS systems have enabled cost effective modelling of very fast craft. Their handling characteristics can now be assessed accurately at an early stage of the design. This helps to ensure a successful boat, determine the acceptable boundaries of the design, or modify it to eliminate any problems found.
The video below shows typical high speed manoeuvring trials conducted by the Wolfson Unit, courtesy of Tehnomont Shipyard, Pula, Croatia. All our free-running trials are conducted in the Southampton area, where large sheltered spaces are available.
For more information on our range of services see our services page.
The Wolfson Unit wishes to congratulate gold medal winner Amy Williams and the British Bob Skeleton team on their fantastic result in Vancouver. The UK Sport Research and Innovation Performance team has funded a four-year research programme at the University of Southampton to help improve understanding of bob skeleton performance. The research has been conducted by Engineering Doctorate students Rachel Blackburn and James Roche, under the supervision of Dr. Stephen Turnock with the support of Wolfson Unit staff.
Unit Engineers have had the privilege of working with top athletes in a number of sports, notably the British Cycling team, helping them win Gold in Beijing. The Unit has also worked in close contact with the rowing, sailing and canoeing squads towards the 2008 Olympics, where the target number of medals has been exceeded. The Unit prides itself in having assisted both athletes and technical staff over the last few years, focussing on direct performance gains and improving understanding of the complex physics involved.
WUMTIA is one of eight organisations chosen as Innovation Partners to UK Sport’s Research and Innovation programme, providing support to the UK's best athletes and coaches so that they can reach their full potential in the Olympics and other international competitions.
The Wolfson Unit is pleased to announce the launch of Hullscant Rudder, an additional module within Hullscant. The new module calculates the structural properties of a vessel’s spade rudder, and compares it to the requirements of ISO 12215 Part 8. The Rudder module uses the boat definition from HullScant.
New clients can purchase Hullscant plus the Hullscant Rudder module for £1275. Existing Hullscant customers can upgrade to the new module for £300, which includes full support from Wolfson Unit engineers. The new program can be downloaded from the Customers Download area of our website and existing hardware locks will be updated remotely.
If you would like to order the new program, please complete our Software Order Form and email or fax to us. The Wolfson Unit staff will be pleased to discuss the new program if you have any further queries.
Visit our Software Page to download the Hullscant Rudder datasheet and to see the full range of Wolfson Unit Software.
Ian Campbell used the Wolfson Unit’s WinDesign VPP to analyse the performance of Alinghi’s catamaran and BMW Oracle’s trimaran prior to the America’s Cup that was sailing in Valencia last week.
The predictions were published in the February edition of SAIL Magazine in the USA and included Polar curves and a table of winning times (below).
The rigs had changed considerably since the VPP predictions and in particular BMW Oracle had sprouted a wing rig that had grown even taller in Valencia. Jury rulings had also affected the boats. The outcome was, however remarkably close to the predictions and the key to success remained as predicted, a powerful rig attached to a stable platform proved fastest.
The Wolfson Unit was represented in Valencia by Ian Campbell and Andy Claughton and they hosted on their return a seminar attended by 80 University Ship Science staff and students that produced a very lively discussion about the racing and the boats.
More and more complex geometry definitions are making it harder and harder to do simple calculations. The editorial ‘Complex geometry, simple files’ written by Andy Claughton for ‘Ship & Boat International’ is focused on the effective manipulation of various Computer Aided Design (CAD) files and formats without losing important geometrical information. The editorial illustrates simple guidelines to obtain files for hydrostatics, stability, VPP and Computational Fluid Dynamics (CFD) calculations with the help of commercial CAD packages and freeware software such as the Wolfson Unit‘s DXFtoLFH converter.
Barry Deakin will take part in the second Chesapeake Powerboat Symposium in Annapolis in March, to present a paper that he has written with Dickon Buckland.
Self propelled models under radio control have been used for many years to assess the manoeuvring and handling of ships. The limitations for testing small, fast craft have been linked to the low model weight required and the ability to install enough power, as well as the cost of modelling. Engineers at the Wolfson Unit have developed test methods appropriate for studying the particular problems of small craft, with small budgets, but model speed has always been limited by the available components.
Recent advances in motor and battery technology, the availability of model water jet drives, and developments in small data logging and GPS systems have enabled cost effective modelling of very fast craft. Their handling characteristics can now be assessed accurately at an early stage of the design. This helps to ensure a successful boat, determine the acceptable boundaries of the design, or modify it to eliminate any problems found.
For more information on our range of services see our services page.
The Wolfson Unit continues to work with a range of Olympic sports as UK Sport partners. The Unit has made extensive use of the University of Southampton wind tunnel facilities for sports including downhill skiing, as part of their aerodynamic development programme for the Vancouver 2010 Olympic games.
Follow this link for a BBC video article from Ski Sunday.
Wolfson Unit MTIA, Building 15/A,
University of Southampton, Highfield, Southampton SO17 1BJ, UK Telephone: +44 (0)23 8058 5044
Fax: +44 (0)23 8059 7594
Email:wumtia@soton.ac.uk
