Steve, Tim and Scott at Portland Harbour, during Weymouth Speed Week, October 2010

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