Previously, to assist in counterbalancing the pitch and roll moments of the boat, our design included an outrigger located behind the wing-sails to seat an additional crew member whose weight can be positioned on either outrigger float, depending on which tack the boat is on. This configuration with two crew members, one pilot and one acting as

counterbalance, has been improved upon by replacing the additional crew member with a moving mass located within the fixed outrigger structure that can be controlled by the pilot. This change simplifies the design, increases safety and reduces drag.

Scott

You may have noticed a slight name change to ‘v-44’ along with some changes to the layout of the boat. Firstly, the change to ‘v-44’ is simply to reflect the fact that the overall length has increased to 44’. We have developed a new main hull configuration where the entire hull remains upright (as opposed to only the forward section).  This new hull layout has a cockpit located behind the wing-sails, above the waterline.  The hull has an increased slenderness ratio and since it remains upright, it now has a more classical shape for low wave drag.  The two wing-sails and keels are rigidly connected through the hull centre section. The pilot retracts a fairing which covers this section, allowing the wing-sails and keels to rotate through 90 degrees as the boat tacks.

A second crew member will be stationed on the windward outrigger of two additional fixed outriggers.  The second crew member / fixed outrigger combination will assist with the tacking process and benefit the overall boat centre of gravity position.  The cross member supporting the two fixed outriggers is streamlined.  Two full length trailing edge flaps acting as ailerons have been introduced to the cross member to give an additional rolling moment boost (opposing the heeling moment from the vertical wing-sail).  This additional moment will increase with speed and compensates the increasing heeling moment as the boat rides higher at high speed.

Performance wise, we have reduced the loading on the keel and relaxed the target lift/drag ratio of the boat to 2.3:1 to allow us to push the VNE (velocity not to exceed) to 70 knots.  This will necessitate a 30 knot wind.  Recent changes to the boat’s layout have enabled us to ride higher, above larger waves, and yet still maintain overall roll balance of the v-44.

Our progress with Coupled CFD and Structural Analysis of the v-44 has gone up a gear, since the VERNEY Speed Sailing Project is now the proud owner of a Cluster. Our dedicated Cluster comprises of 24 compute nodes and will allow up to a 150 million cell CFD mesh.

Finally, we will be presenting our work at this year’s Simulia Customer Conference in Barcelona, Spain, during 17 – 19 May.  Steve Howell will also be presenting at the Royal Institution of Naval Architects, Developments in Marine CFD conference in London, UK, during 22 – 23 March.

Tim

Steve Howell has recently joined the team as CFD lead and will be carrying forward the great work currently being carried out by Igor, Konstantin and Tomasz at Capvidia.  We have also gained a new sponsor, Prospect Flow Solutions, who are an engineering design and analysis provider to the world energy industries. Prospect is the perfect company to have on board as a technology sponsor, no matter where they are based in the world - they just happened to be headquartered down the road from us in Aberdeen, Scotland.  In fact, I believe that Aberdeen is probably one of the best places in the world for us to be based – just a long way from Portland!

Steve, Scott and I met up in Portland during Weymouth speed week this October. The task was to understand better the layout and conditions of the inner and outer harbour areas ready for our record attempt..

We are currently focussed on carrying out CFD analyses of the aero- and hydro-dynamics of the boat using FlowVision HPC from Capvidia and Abaqus from Dassault Systemes Simulia.  For the above-surface aerodynamics, each fluid structure interaction (FSI) analysis couples Abaqus with FlowVision and involves capturing the movement of six independently rotating surfaces (four wing-sail planks and two outriggers) at different speeds across the boat’s speed range. This process helps us to tune the control system and allows us to virtually test sail the boat before it is constructed.

We are also carrying out detailed tuning of the carbon fibre and titanium keel using xfoil and Abaqus.

Tim

Some more great news too; we are now sponsored by Dassault Systemes under their Passion for Innovation scheme http://www.3ds.com/company/passion-for-innovation/program/ Dassault Systemes are the parent company of both Simulia and SolidWorks. Tim

The skins are a composite of structural foam and Mylar. This is modelled in Abaqus using a composite layup. Tension was applied to the Mylar layer by applying a temperature predefined field and  including an expansion (contraction) step.

We were very pleased that this worked well! It will enable us (in the detailed design phase) to optimise the wing skins to give a good balance between weight and rigidity. We will be able to play around with the foam density, thickness, Mylar weight and tension to minimise the distortion of the aerofoil under local aero loading, whilst saving on weight.

Click on the wingsail spar image to view movie.