Archive for the ‘CFD’ Category
George Sakellaris and the team aboard the Reichel/Pugh mini-maxi Shockwave crossed the finish line off Bermuda’s St. David’s Lighthouse Monday morning at 5:34 race time EDT (6:34AM local time). Her elapsed time was 63:04:11. The close contest between Shockwave and her rival Bella Mente, Hap Fauth’s 72 foot Judel/Vrolijk mini-maxi, was a near repeat of the 2012 race, where both boats smashed the course record and finished with Bella Mente a mere 3 minutes ahead. This year, Shockwave led by seven minutes, after the two had battled head to head within sight of each almost continuously for over 635 miles. Although the boat for boat racing was close, Shockwave won comfortably on corrected time besting her rival Bella Mente by 1 hr and 44 minutes in ORR and similar margin in IRC.
As with the 2012 Race, Robbie Doyle sailed as the “stratitician,” working with the navigator, Andrea Visintini, the Tactician, Stu Bannatyne, skipper George Sakellaris and overseeing the sail program.
Doyle said, “There was a constant analysis and dialog onboard as the position of the Stream was fluid, and the weather pattern was also shifting. We had to hunt to find the (Gulf) Stream… we never found the 4 knot real road to Bermuda. It had broken up before we got there. Forecasters had predicted it might, but they suggested we might get there before it would start to dismember. The Stream was really breaking up pretty quick.”
“We tried some new ideas and ways to optimize the boat for the ORR rule” explained Doyle. “Bella Mente is a more powerful reaching boat than Shockwave so in order to defend our 2012 victory we felt we needed to improve our rating as we did not feel we could beat her in a reaching drag race which the Bermuda Race can often be. After a detailed weather analysis of the past 10 races over a 20 year period we made the decision to switch to a fractional spinnaker hoist. We designed and built a new full size Fractional Code 0 (labeled Super-FRO by the crew) to complement our existing smaller FRO. We only carried one free-flying spinnaker and then two Fractional Code 0′s.” Both FROs were set on top down-furlers for easy sail handling and crossovers. The combination proved successful, as the powerful “Super FRO” carried the boat through some crucial transitions. ”Surprisingly its best moment came when VMG running in 8 knots TWS into head seas with Bella Mente right on our tail. Even though she was carrying a full size mast head spinnaker we were able to open up on her with the more stable Super FRO.”
“We had one day of practice with the Super FRO, during which we saw what a powerful weapon it could be, but also how much it really loaded up the sprit. We had Doyle’s CFD team working with Reichel/Pugh’s office to re-engineer the sprit to handle the sail, and the guys were reinforcing the sprit until 3am the morning of the start! A total team effort to pull off this incredible result again.”
The win adds to Shockwave’s growing list of recent victories, highlighted by their division win in the 2012 Newport-Bermuda Race, the 2013 Montego Bay, and the 2014 RORC Caribbean 600 Race. Originally launched in 2008 as Alpha Romero 3, Shockwave has proven to be a dominant force in the last 3 years. Doyle Sailmakers has been intimately involved in the boats resurgence, helping optimize not only the sail program, but also the mast and keel for a full aero and hydrodynamic package.
For more information on the Newport-Bermuda Race, please visit here.
Results from this years race can be found here.
George Sakellaris’ R/P 72 Shockwave took the overall IRC win in this year’s Caribbean 600, correcting out to finish roughly 1 hour ahead of rival Bella Mente. After 600 miles of racing, Bella Mente, Rambler 90 and Shockwave crossed the line within 15 minutes of each other, after close racing all along that saw numerous lead changes. The win adds to Shockwave’s growing list of recent victories, highlighted by her Gibbs Hill Lighthouse Division win in the 2012 Newport-Bermuda Race and first in the 2013 Montego Bay Race. The overall IRC win was the highlight of a number of impressive finishes for Doyle-powered boats, with Line Honors for Bella Mente – carrying some specialty reaching sails from Doyle and featuring Doyle’s own Mike Sanderson as a helmsman, Botin 65 Caro, with a full Doyle Stratis inventory taking 5th overall in IRC, First 40 Lancelot II winning IRC Two with a new Doyle Stratis Mainsail, and the 62m Hoek Schooner Athos greatly improving on last years performance and battling it out with longtime superyacht rival Adela.
A grueling 600 mile race circling around many islands, with stiff breeze the whole time, the race places a premium on having a well prepared boat and crew. In anticipation of this year’s race, Doyle refined the sail inventory to make sure that the team would have the right sails, without carrying too many. Robbie Doyle, who in addition to managing the sail inventory served as Shockwave’s tactician for this race, explains the thought process, “We looked at the conditions that we were likely to see, and then when designing and building the sails worked to make sure that their ranges were as large as possible. Thankfully our Stratis process allows us to make some of the lightest sails available, so we increased the DPI’s a bit to ensure we could carry the same sails longer.”
“With the amount that conditions change in this race, sail changes can just be too costly. In the end, we used the J2 (Medium Jib) 95% of the time, and just twisted it off a bit in the bigger squalls. We only carried 3 jibs, which helped save weight.” Flying the same jib up the majority of the race allows the crew to stay aft and on the rail, keeping the boat moving. The other big change was adding a new Fractional Code 0. “After last year’s Montego Bay Race, we looked at our sail inventory and felt that the jump from the Jib Top to the Code 0 was too big. We built a new FRO to fill that gap. It was the workhorse of the race, as coupled with the Top Down Furler, we could leave it up, and just furl or unfurl as the conditions changed without any drama on the foredeck.”
Owner George Sakellaris was pleased with the results. “I have a great crew and it was an excellent race, lots of wind and the racing was very close. I have done many offshore races but this is the first time I have raced this one and it was against tough opposition. I think the winds were favorable to us and the Shockwave team used that to our advantage. At the end of the day, winning yacht races is all about the team performance more than anything else.
Robbie Doyle was similarly enthusiastic after the race. “That is what ocean racing should be all about. Beautiful racing between three very tough competitors, all fighting it out the whole way. A heavy-weight battle without a doubt – no question. I have had great moments in sail boats, but that was as much fun as I can remember. For 600 miles we were always in touch with each other, either up a few minutes or down a few minutes, and it all came down to the last beat to finish. It was like an epic tennis match.”
Next up for Team Shockwave will be defending her Newport-Bermuda Race victory in June.
Gallery: Doyle Sails in the 2014 Caribbean 600
Having proved her mettle for inshore racing, Shockwave, driven by owner George Sakellaris followed up her recent Key West victory with a near record breaking performance in the 2013 Montego Bay Race. Stretching 810 miles Ft. Lauderdale to Montego Bay, Jamaica, Shockwave and her crew were able to complete the course in an impressive 2 days, 11 hrs and 23 minutes and missed the course record by a mere 58 minutes. On corrected time, she also won the IRC division.
The race started in light wind that went down to 2 to 3 knots the first evening. The following day, Shockwave made big gains towards the record reaching along Eleuthera and Cat Islands, averaging 20 knots with her Code 0. After rounding the tip of Cuba she hit a high of 26.4 knots using her newest A4 spinnaker and was on pace to beat the record only to be thwarted by a lightening wind that shifted aft as she approached the finish, protecting the record set by Titan 12 in 2005.
The Reichel/Pugh designed, McConaghy built Shockwave is powered by a 100% Doyle Sail inventory tailored to match the boat’s performance curve using the latest analysis and insight from Doyle’s in-house CFD and design team. For this regatta, Shockwave was utilizing her 2-year old offshore race main – the same sail that carried her to victory in last year’s Newport-Bermuda Race. “The success of the sails we are using is a clear indication of the durability and strength of the Doyle Stratis laminates,” tactician Robbie Doyle pointed out. The Code 0, an ultra-light Doyle Stratis sail with curved radial seams for super-precise shaping and strength, was used for about 50% of the miles sailed and once again proved to be the most versatile and easy to handle headsail in the inventory. By combining practical experience with cutting edge design resources, Doyle’s team has been able to deliver sails that clearly enrich the performance of the boat and the crew.
Next Team Shockwave will head to the Mediterranean for the PalmaVela regatta in May. Be sure to Like Team Shockwave on Facebook to stay up to date with her activities.
For complete race results, visit the event website.
For information on how Doyle Sailmakers can help your next project, contact your Local Doyle Loft.
After winning IRC 1 of both the 2012 Charleston Race Week and NYYC Annual Regatta, and then overall in the 2012 Bermuda Race professional division under both IRC and ORR Shockwave ended her 2012 racing season with an unfortunate “bang” – hitting an unmarked rock in Sardinia. She has opened her 2013 racing with a different impact – by defeating one of the latest designs, and current mini-maxi World Champion, Bella Mente, in a head to head battle in the 2013 Key West Race Week.
Photo Credit: Chris Odom/ChrisOdomPhoto.com (www.chrisodomphoto.com)
Turning the 5 year old 72’ Shockwave into one of the winningest programs in the world has been an ongoing process that has challenged all aspects of Doyle Sailmakers and its sister engineering company, Doyle CFD, as well as the entire Shockwave Racing Team. Doyle Sailmakers combined data and feedback from sailing the boat with an advanced scientific approach – utilizing the latest CFD and FEA to analyze highly defined driving and heeling forces and the resultant loads - to make decisions on not only sails but also integrating mast and bulb shapes. It has meant working closely with the design team at Reichel-Pugh, as well as the mast designers and other hardware suppliers to ensure that everything worked cohesively. The confidence of owner-driver George Sakellaris and his captain Reggie Cole has been a major factor as well.
The challenge was not only to catch up to the top boats of the time, but to improve such that Shockwave was competitive with the newest boats coming out of the design offices, as well as to keep up with the top boats that were always being tweaked for just a bit more performance. Step one was to completely model the boat using CFD to try various sail shapes and sail configurations to see how various options would affect the driving and heeling forces while at the same time keeping an eye on the rating. Doyle CFD came up with a main design that had a significantly larger square top than conventional IRC wisdom recommended at the time due to the rating “penalty.” However, the analysis showed that with the optimum section shapes it would increase speed enough to more than offset the rating increase. It proved effective enough to help the boat to a second place at 2011 Copa del Rey series in Palma, and a 3rd in the 2011 Maxi-Worlds. Sail by sail, the entire sail inventory was replaced, carefully analyzing new shapes to determine interaction with other sails as well as the hull and rig. The latest FEA analysis allowed Doyle’s design team to optimize string layouts in the sail, resulting in significant weight savings over the previous inventory. Not only does the weight that is aloft matter, but the overall weight in the boat matters. In this league everything counts!
Doyle’s CFD analysis combined with RM analysis confirmed what was known from sailing – Shockwave was a bit challenged in stability to be a truly all-around boat. Additionally, the mast was more limber than was preferred, preventing simply modifying the keel. Thus, a new mast and keel were ordered. Many mast sectional options were considered as one had to weigh the increased windage of the larger section versus the increased weight of a smaller, heavier walled section. Shockwave ended up with the best of both as by starting with the large section and using CFD to re-design it to minimize windage for upwind sailing angles she ended up with the lightest mast that matched the low windage of the smallest proposed section.
While stiff enough to be effective up and downwind the boat was still going to be challenged on a reach. On the water trials confirmed what CFD had indicated: the boat still didn’t have the Righting Moment to effectively carry an A3 Reaching spinnaker in any significant breeze. The Bermuda Race was one of the top goals for the 2012 season – and typically features plenty of reaching. Trial CFD runs were performed with smaller A3s as well as large reaching headsails for which a penalty would be paid, as well the “Reaching Code 0.” Because it carried no penalty and could be tailored to match our Righting Moment, the “Reaching Code 0” was decided upon. It was a good choice. Shockwave carried the sail about 65% of the way to Bermuda and led to her victory. Using the ultra-lightweight Stratis membrane made this sail extremely light weight and yet tough enough to withstand the typical Gulf Stream squalls.
Following the meeting with the rock in Sardinia there was no choice but to get a new keel and bulb. John Reichel of Reichel-Pugh and Tyler Doyle of Doyle CFD burned the midnight oil trying many iterations of bulbs before deciding on one that not only added significant stability upwind but has clearly improved Shockwave’s off the wind performance.
When interviewed after winning this past Key West Race Week, Robbie Doyle was asked “What has Shockwave done to get her performance to where it is today?” His response pretty much summed up the story: “Nothing really major, but many, many, many little things. The Team has come together in all aspects of execution, and the boat is in a truly sweet spot in terms of balance. We have used a chisel rather than a hammer.”
In advance of Key West, the design team worked on a new concept A1 for VMG course racing in under 7 knots, which proved very successful. A new A1.5 was made with lighter materials and a slightly larger range to tie in with the new A1, and a new A4 that reflected refinements over the previous sails. In addition, a new Spinnaker Staysail was made that was substantially lighter than its predecessor and with a smoother furling system for easy sets and douses during inshore buoy racing. With regards to upwind sails, the boat was sporting a new, larger mainsail and a new J2 that was designed for a balanced entry and twist profile with tighter sheeting angles.
Next up for Shockwave is the Jamaica Race in February.
Shockwave was lucky enough to have Chris Odom onboard Wednesday, who produced this video of the action during the days racing.
by Robbie Doyle, Shockwave’s Tactician/Navigator
The 2012 Newport to Bermuda Race was about record breaking speed and problem-free sailing in challenging conditions. This year’s overall fleet winner in the Gibbs Hill Lighthouse Division under both ORR and IRC was the 72′ Shockwave owned and skippered by George Sakellaris and powered by Doyle Sails. Key to Shockwave’s success was selecting the ideal inventory for conditions and the ability to deploy and furl her Code 0, with complete confidence and full control in very challenging conditions. The sail had to roll tightly, so it could be left up for periods of time. Doyle developed a unique top down furling Code 0 to make this a reality.
Most significant was Doyle’s use of high resolutions RANS CFD to analyze Shockwave’s sailing characteristics versus her sail carrying ability. Doyle analyzed five different sail combinations to evaluate the driving force versus heeling moment to determine the optimum sails to carry aboard for the race. Specifically the analysis compared a conventional double head rig, a mast head Code 0, a fractional Code 0, an A3 and an oversized reacher (a large LP headsail with penalty.) Initial CFD analysis revealed that Shockwave would require more power than the standard jib top and genoa staysail, double head rig could provide. Further analysis illustrated there would be a very narrow window where an A3 could be successfully carried from a stability standpoint. The free luff of the A3 would also make it a difficult sail to drive through waves. Yet, knowing that with the right sail combination Shockwave had break-a-way speed potential it was ultimately determined that a mast head Code 0 delivered the most driving force over a wider range of conditions for a given heeling force than the other combinations. The tight luff of the Code 0 provided additional benefits as well. The sail could be depowered without fear of collapse, and it would be very stable for driving hard in offshore conditions.
The next step was to apply the CFD derived sail forces to a FEA structural model of the sails to determine the lightest Code 0 that could be built for Shockwave. The CFD/FEA analysis suggested that a sail half the weight of the existing Code 0 provided by another sailmaker. The weight savings would also make the sail much easier to handle.
Not satisfied with the current state-of-the-art in Code 0 furling Doyle partnered with Future Fibres and KZ Marine to develop top down furling for a Code 0 with an internal torque cable in the luff. Previously, top down furling has been used for free flying, downwind sails with the torque cable external to the luff of the sail. Shockwave’s Code 0 was designed from the outset to use top down furling gear with the torque rope in the luff. This new adaptation of top down equipment created a system that worked flawlessly during the race. The top down approach rolls the head of the sail very tightly and the tight roll continues down to the tack, compared to conventional furling gear that furls the sail tightly at the tack and loose in the upper leech where the roach often never furls properly. The tightness of the furl Shockwave minimized windage when the sail was left furled during rapidly changing conditions and greatly improved handling the sail. The crew was always confident that the sail could be deployed without prematurely unfurling and the tight furl made dropping the sail to deck much easier.
Ultimately, Doyle’s diverse engineering capabilities combining CFD/FEA, sail design and design of the sail handling systems for the Code 0 were a significant contribution to Shockwave’s victory over her newer rivals.
by Robbie Doyle
The 2012 Newport Bermuda Race started on Friday June 15th with a total of 166 entries. This year’s race was by far the fastest one ever. The first three finishers: the 90′ Reichel/Pugh Rambler, the latest 72′ Judel/Vrolijk Bella Mente, and the 72′ Reichel/Pugh Shockwave all shattered the old elapsed time course record, with Rambler setting a new record of 39 hours and 39 minutes, beating the previous Lighthouse Division course record set by Roy Disneys Pyewacket in 2003 by over 14 hours.
Shockwave Wins Five Awards
The Newport Bermuda Race is sailed in two divisions: the amateur crewed division that races for the St. David’s Lighthouse Trophy, and the professionally crewed division, which competes for the Gibbs Hill Lighthouse Trophy. Both divisions race under two different rating rules: the condition variable ORR and the single rating IRC.
This year’s overall fleet winner in the Gibbs Hill Lighthouse Division under both ORR and IRC was the 72′ Shockwave owned and skippered by George Sakellaris and powered by Doyle Sails. The North Rock Trophy, awarded to Shockwave as the IRC corrected time winner of both the Gibbs Hill and St. David’s Divisions, is a silver replica of the 1960-1990 North Rock Light Tower that once warned mariners of the rocky approach to Bermuda from the North.
This was George’s first Bermuda Race and marks the third major victory for Shockwave this year, starting with Charleston Race Week and then the New York Yacht Club Annual Regatta. While her results so far this year have been consistent, it is remarkable to note that between Charleston Race Week and the NYYC Regatta, Shockwave was fitted with a new mast and every sail in her inventory needed to be heavily modified to fit the new rig.
In the three weeks between the first sea trial of the new mast and the start of the Bermuda Race, Doyle’s team of sail designers and sailmakers worked tirelessly to adapt the existing sail inventory to fit the new dimensions of the rig and associated hardware and produce winning sails. The combination of experience sailing the boat and CFD/FEA analysis helped Doyle guide the boat through a seamless transition that produced sails that performed brilliantly out of the bag.
The jumbo head configuration of Shockwave’s carbon fiber Stratis main was optimized for IRC using Tyler Doyle’s CFD/FEA analysis, matching the boat’s stability verus the driving force and heeling force of the sail. Shockwave’s offshore main used in the Bermuda Race is estimated to be 40% lighter than our competitor’s similarly sized 3Di sail.
Similarly, the shape and construction of our Stratis Technora Code O was optimized using the combined CFD/FEA analysis. Even the aerodynamic sectional shape of Shockwave’s new rig was optimized using Doyle’s CFD analysis. While the resources required to run full RANS CFD/FEA analysis is not trivial, it ends up being much more efficient than multiple rounds of sail testing in real life and makes the reason for one sail’s advantage over another much easier to comprehend.
Shockwave’s latest secret weapon was an ultra-lightweight, high-performance, Stratis Code O on an innovative furling system that she used at both the start and finish and about 40% of the miles covered. This sail carried Shockwave to speeds as high as 24.9 knots! Many on the crew attributed this sail in their 30 minute victory on corrected time. See photo of Shockwave’s Code 0.
Three keys to the race were:
1. Choosing the right sail inventory for the race based on weather forecast. Key to our inventory call was taking a Code 0 and not an A3 spinnaker. We also had a jib top and genoa stays’l. In addition to the main, those were the three sails we used the entire way.
2. Hitting the stream just right. Navigationally, we nailed the entry and exit point of the stream and had 5 hours of 3+ knots of favorable current.
3. Helmsmanship. To drive the boat as hard as we did and not have any damage required some very good helmsmen, and we had a handful.
- Robbie Doyle
Altaeros Energies, a wind energy company formed out of MIT, recently completed testing of a 35-foot scale prototype of the Altaeros Airborne Wind Turbine (AWT) at the Loring Commerce Center in Limestone, Maine. The prototype, fabricated in partnership with Doyle Sailmakers of Salem, Massachusetts, achieved several key milestones. The AWT climbed up 350 feet high, produced power at altitude, and landed in an automated cycle. In addition, the prototype lifted the top-selling Southwest Skystream turbine to produce over twice the power at high altitude than generated at conventional tower height. The turbine was successfully transported and deployed into the air from a towable docking trailer. Watch the video below of the prototype’s test.