Speeding up the design curve
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How design software iQ Technology saves time and improves the final product...
Technical
Brief
‘Technology is democratic because it always reaches the enduser.’ It’s a favourite saying of Joan Subirats, Quantum Sails’head of technology in Barcelona. ‘It also applies very well towhat we’re doing at Quantum, with the trickle-down oftechnology to all our customers.’ At the top of the racingpyramid are classes like the TP52, where the Quantum Racingteam recently won the world championship. But whateverlessons are learnt on the grand prix circuits get passed downto every other Quantum project.
The development of asail package for the newFarr 280 One Design is agood example. Quantum’svice president of qualitycontrol, Andrew Scott,worked closely with FarrYacht Design and SouthernSpars in the early stages ofthe design. ‘We took alltheir VPPs, al l the r igdimensions – even down toall the rod values and howmuch the rod stretches –and we input this wholeboat into our iQ Technologysystem in order to properlyset up the rig for the firstt ime. It was prettyimportant for us to be ableto come out of the box with the right luff curve on themainsail, the right geometry of the headsails, with us swinginghard, having done some good due diligence.
‘The process from there was to trim the boat to what wefelt was correct, based on what we have learnt from doingother programmes. We input rudder loads and mainsheetloads and then we see how much the mast is going to bend.’According to Scott, matching luff curve to mast bend is one ofthe critical success factors. ‘The luff curves have to be perfectbecause with all the shapes and membranes – when the sailsare built out of carbon fibre – nothing moves. So if you don’tnail the luff curve the first time, then the sail is not going tolook right and you are back into the loft for recuts in order tomake it fit the boat. By using our systems we were able to nailthat first time out, which was helpful for the guys on the boat.
They could just pull it up, sheet in, and go.’In the case of the Farr 280 Scott estimates that the iQ
design process saved at least two or three trips back to theloft to adjust the luff curve. ‘We probably removed one or twogenerations of sails from the design cycle because we knewwhere the fibres needed to be, we knew how the batten layoutsand batten angles needed to be. The iQ system helps us figureout all those little things early, and get them right first time.’
Using powerful computational tools like iQ allows thedesigners to envision the flying shapes and work with moreaccurate data for a number of other key areas including:
• Designing jibs for the desired range of wind (fuller or flatter)and having the control of the luff curve, geometry (clewheight, distance to spreaders, not touching rig, etc)
• Detailed analysis of headstay tension to design themainsail. Having more defined fore-aft and side mast bend,so that the mainsail’s luffdefinition is better.Even so, however good the
technology, people still matter,and you need a good saildesigner to see the projectthrough from start to finish. ‘Itis still a soft sail going into ahard surface, so it is nevergoing to behave 100% the wayyou thought in the designprogram,’ says Scott.
Enter Quantum's JordiCalafat, 470 Olympic goldmedallist and America’s Cupwinner with Alinghi, who hasled the on-the-water saildevelopment on the Farr 280.‘Obviously you still need human expertise,’ says Calafat. ‘Whenyou are running flying shapes in iQ membrane, in reality you getone snapshot of the sail. Of course you run different conditionsto see how it behaves when overpowered or underpowered, tomake sure you have the right amount of luff curve, but what itgives you is a starting point. You start from a better position byhaving these tools; but for after this, as a designer, the mostimportant thing is the communication with the trimmers. Thebetter the input they give you, the quicker we can develop thesails to reach their optimum performance.’ q
Initial CFD aero forces at 12kt
Stress, strain, loads and flyingshapes are calculated in the FiniteElement Modelling module
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