May 16, 2010

CS Interview: Martin Fischer

Martin Fischer is one of the fathers of modern racing beachcats, but he also has worked in some key big multi projects like Groupama II-III and BOR90.
Many catsailors have heard his name, but there is not much info available on him. Martin was involved on the first A-class wave piercer, the F18 Capricorn and the latest Hobie racing extreme machine, the Wildcat, among many others. And surprinsingly he is a reader of the blog too(!?)

This is by far the best piece of information displayed in this blog and I want to thanks Martin for his detailed answers and interest. Keep tuned for future info on his flying A-Class... ---- Portrait by Alex Udin
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CS- You are known as 'Dr. Martin Fischer' , which is your academic/professional/sailing background?
Martin Fischer: I studied physics in Hamburg / Germany with a focus on fluid dynamics. During my diploma thesis I worked on a method to develop and optimize wing section. After my studies I made a PhD in geophysics on climate predictions, using coupled ocean atmosphere models.

After that I continued working on climate research for about 5 years, first in Germany and then in Italy.
In 2000 I moved to New Caledonia (South Pacific) and founded a small company that works on studying the impact of climate variability on economic activities like energy consumption, prices of electricity and gas, and carbon emission certificates.

In parallel I have always been working on multihull design. I have been racing A-Class Catamarans for about 15 years, so I logically started my design work on the A-Class. In December 2002 an F18 regatta with participants from overseas was organized in New Caledonia. Together with 3 friends we decided to build a new F18 boat for that race (More on Cap below) Since that time I have been racing F18 catamarans. Shortly after the appearance of the Capricorn I met Franck Cammas – the skipper of the Groupama boats – and I started working on rudders for him.

I've been working on appendages since then for Groupama-2 (60-ft ORMA trimaran) and Groupama-3 (105-ft Maxi trimaran, holder of the Jules Vernes Trophy), and I was involved in developing the shape of the floats for these two boats.

Beside that I also designed appendages for the ORMA-60 Banque Populaire (rudders and daggerboard) and for the Maxi Trimaran of Thomas Coville Sodebo (rudders, daggerboard, and recently curved foils).


Example of Fluid Dynamics analysis

- CSN: Which new technology and tools are being used today in naval design that weren´t available 10 years ago?
MF: In my opinion the biggest change between 10 years ago and now is the use of hydrodynamic RANSE simulations (Reynolds Averaged Navier Stokes Equations).
10 years ago we already used CAD design tools to create 3-dimensional designs and finite element simulations were used for the structural part of a boat.

Hydrodynamical simulations, however, were only very briefly used – at least outside the America’s Cup – and the results were not always satisfying. Today, highly sophisticated codes exist, that allow a complete and realistic hydrodynamic simulation of hulls – with and without appendages – and rigs.

These codes can nowadays be run on powerful workstations (high-end PCs or Clusters of PCs) which makes this kind of simulation accessible outside the America’s Cup. Nevertheless it is still a rather complex and costly thing to do, that requires expert knowledge. I am working with a company in France (www.k-epsilon.com) that is doing this kind of simulations for me.

- CSN: Designs now are fully tested previously in virtual enviroments?
MF:No, it is to my knowledge still the exception. A full RANSE simulation is still a costly thing to do. For large projects (America’s Cup, Volvo Ocean Race, 50+ ft racing yachts, 70+ ft cruising yachts, …) it has become a standard, but for smaller projects it is often too costly. For the Wild Cat we ran such simulations, but that was only possible because Yann Roux, the owner of k-epsilon was personally interested in the project.

- CSN: How accurate this tech is?
MF:It is difficult to provide general numbers on the simulation error. We did tests on a multihull, comparing numerical results with measurements (drag) of a hull model in a towing tank. The simulation error was of the order 2% to 3%, but such results cannot be generalized. In other cases the error may be bigger, but in general the numerical simulations allow – with very good accuracy – to rank different candidates.

- CS: Testing models in pools is still used? 1:5 Protoypes are not necessary any more?
MF:Tank testing is still used, but I reckon that nowadays numerical simulations are more accurate than tank testing, at least for sail boats. The reason is the following: Let’s assume we have a model of a boat at a scale 1:4 (this is already a big and expensive model). In order to get the wave pattern in the tank right, we must reduce the speed of the model by a factor of square_root(4), hence by a factor of 2.
This ensure that the so called Froude number of the model and the real boat are the same. So far so good.

In order to get the viscous drag right, we must ensure that the Reynolds numbers of the model and the real boat are the same, and to do so we must increase the speed of the model by a factor of 4! And that’s the problem.

It is impossible to get the Froude number and the Reynolds number right at the same time. There are techniques to compensate for that, which result in correction factors, but these correction factors also exhibit errors.

To my understanding the errors of the correction factors are nowadays more important than the errors of numerical simulations, which is the reason why I have a strong preference for the simulations. Another advantage of a numerical simulation is that it provides detailed information. It is possible to study in detail why one shape is more draggy than another one.

- CSN: As an expert in Fluid Dynamics, in which state or % of possible development we are now in yacht hull design? how much advanced multihulls can get without ending in Hydroptere clones?MF:Very difficult to say. There is always way for improvement. I think the major development steps have always been initiated by new materials. That allows for lighter and stronger constructions, and hence for new shapes that were impossible before.

- CSN: Is possible to see in the future a established racing class of foiling beachcats ?
MF: Yes, I am absolutely convinced that foiling multihulls are the next step. The challenge is to make them reliable and easy to handle. I am currently working on putting an A-Class on foils. First tests are very promising. I start flying the boat, also it is not very stable yet, but I think we will get there.

- CSN: I've heard from Landy in the A-Class, from M20 pics and reports and from Macca in the Nacra F20 how they are flying with curved boards, so slowly we are going in that direction, not full hydrofoils of course, but is the future in your view (flying beachcats Moth style)? MF: Yes, I have here in New Caledonia an A-Class with curved foils. The boat works nicely but it is not yet fully air-borne. If everything works according to plans I’ll have a flying A-Cat before the end of the year.

- CSN: List of major boats/projects/cats you´ve design or projects being involved I have been working on (either alone or as part of a design team) : MF:
-Mikan: A-Class that I designed in 1996
-F2000: 20ft carbon racing catamaran designed for the ISAF trials in 2000 for a new boat for the Olympics
-Capricorn: changed probably the F18 Class
-Ventilo F18-HT: F18-Ht for Ventilo
-Groupama 2: Appendages and part of the float design, ORMA-60 that has been very superior in the ORMA Class
-Groupama 3: Appendages and part of the float design, holder of the Jules Vernes Trophy -Banque Populaire 60: Appendages, closest competitor of Groupama-2
-Sodebo 105: Appendages, holder of the single handed 24-hour record, now fitted with curved foils
-Wild Cat: Hobie’s new F18 boat
-Coste-40: Ocean going 40-ft racing trimaran with foils, currently under construction in Noumea
-Oracle Trimaran AC-33: First set of rudders and daggerboard and part of the float design
-Groupama-4: New boat for Franck Cammas, monohull for the Volvo Ocean Race. I am part of the in-house Groupama design team


- CSN: How do you end designing beachcats?
MF:I have been racing beach cats for more than 20 years. I really love these boats and I always wanted to push the limits further. So I started with A-Class designs and moved on to F18s.I also worked with Peter Egner on the “Toy” in the early 90’s.

I then worked on a Scheurer design (Swiss boat builder) and in 1996 I designed and built my own A-Class, the “Mikan”. The number of boats sold remained small (about 15), but the boat was reasonably successful. It never won a World title, but good results were achieved in Italy and Germany.
I designed an F18-HT for Ventilo in 2004. The boat was quite successful in the F18-HT circuit.


- CSN: Which was the 1st wave piercer you've designed
MF:Together with Peter Egner I worked on the design of the A-Catamaran “Toy”, the predecessor of the Flyer. At that time I proposed to Peter Egner to use an inverted upside-down bow. That was in 1990.


- CSN: AC 33 - Did you work on last Americas Cup?
MF:Yes, I worked for BMW-Oracle. At the beginning of the project I was involved in the concept of the boat, the design of the floats and I designed the first set of rudders and the central daggerboard. At the beginning of the project it was not at all clear where the race would be held, so team was therefore looking for a boat that could also survive strong winds and big waves.

Photo: Gilles Martin Raget

- CSN:Which boat/concept did you like best?
MF: I obviously think that Oracle was the better boat. For a boat without any limit on sail area and mast height righting moment is always king. A trimaran is therefore the better choice (in my opinion).


- CSN: What you would have designed or changed if you were head designer for Alinghi or BMW?
MF: Well, that is a difficult question. On Oracle I like (obviously) the floats and I also like the concept of a trimaran without appendages on the central hull. Overall it was obviously the better boat, although it was not the most beautiful boat.
I think the concept of a catamaran was not the right choice for a boat without limits on sail area and mast height.

In order to retain at least some maneuverability they probably could not go (much) wider than what they did, and thus the righting moment of Alinghi was significantly lower than that of Oracle.
Another point was the volume distribution in the hulls of Alinghi. Especially during the second race the boat showed some very significant pitching, which is an indication that the hulls had too much volume in the centre. Of course it is always easy to explain afterward why the others were wrong, so I don’t want to go too much into detail here.

- CSN: The Wing was king? or Alinghi wasn´t sailed to its full potential?
MF: I am absolutely convinced that Oracle also would have won with a soft sail rig, although the margin would have been a bit less dramatic. I think the AC-33 was decided on the design board, well before the first race.


- CSN: The next Cup should be held again in Multihulls? (Today 6 May, Oracle announced that Multis are one of the options) MF:YES, that would the right choice in my opinion. The America’s Cup is the pinnacle of our sport, and the boats it is sailed in should reflect that. Big multihulls are far more spectacular than any monohull, and I am sure it would help to open the America’s Cup and sailing in general to a much wider audience.

- CSN: You forsee working in next AC multihull project?
MF:Well, so far I am flat out with work on the Groupama Volvo project. However, if the next Cup were to be sailed in multihulls I’d be definitely be interested getting involved.


F18 --

- CSN: The Capricorn was one of the 1st cats that changed the game on the F18, can you make a small recount of this project? As it was a huge bet being the 1st ones in the class. 
MF: In December 2002 an F18 regatta with participants from overseas was organized in Noumea / New Caledonia. In Juin 2002 3 friends and I decided to build a boat for that race. I was in charge of the design, and the other three did the building.

The idea was to adapt latest A-Class thinking to the F18 Class.

So we went for rather wide hulls, little rocker, the mast relatively far aft and a real wing mast.
At that time that was almost the opposite of what all the others did. The Capricorn had by far the widest hulls of all F18 boats and at the same time Nacra came out with their F18, which was a very narrow boat.
The tendency for the masts was to go for relatively round masts whereas we chose a mast section from AHPC which was at the maximum of the measurement rules.

For the sails I contacted Greg Goodall, whom I knew from my A-Class sailing. At that time we just bought mast and sails from Greg and he was not involved in the development of the Capricorn.

We launched the boat two days before the start of the regatta for which we had launched the project, so the boat was not at all ready. Although we were far from winning the regatta – which was held over a whole week, running a long distance race every day – the boat showed already its potential.

Franck Cammas, who participated in that race, saw the potential of the boat and invited me in the following to come to Lorient to discuss a possible collaboration. During the 3 months following that initial regatta we really learned to sail the new boat, and it was only then that we realized what we had in our hands, sailing against Tigers and Hawks. We then contacted Jim Boyer and Greg Goodall and asked them if they were interested to take over the concept and to commercialize the boat. It took another year of negotiations and finally AHPC presented the Capricorn in 2004 at the Wolds in Italy.

- CSN: A revolutionary design at the time, but it only managed to grab one 1 WTitle F18 up to now, this of course reinforce the idea that sailors are still key on the F18 at least (just look last AC), but which % do you assign to the overall performace on crew/boat to a good design?
MF: Especially in an up and down regatta with lots of participants the skill of the sailors plays a very important role. This becomes even more important in strong winds, when boat handling becomes an issue.

In the F18 the speed difference between a fast boat and an average boat is of the order of a few percent. This relatively small advantage is not sufficient for an average crew to beat a top crew. Nevertheless the performance of the boat becomes of course a determining factor between the top guys.

There were always good crews on the Capricorn, but never professional crews, which explains probably why the Capricorn got only one World Title. In 2004, at its first appearance we almost managed to win the title.
Mark Laruffa was in very good shape at the beginning of the World, but in the end he was not strong enough mentally to grab the title. It was only in 2006 that we got it right with the Sach brothers the Title and Andrew Landenberger finishing third.

Wildcat photo: Alex Udin

- CSN: Although the Capricorn didn´t manage to swept the Tiger Pro teams, she set the way for the current genaration of wp F18s as the 1st Flyer did, followed by the Infusion that ended Hobie Tiger reign, the J Valer design was king for almost 10 years, by 2008 the Tiger seems outdated, Nacra grabs its 1st Worlds and Hobie needed to renew their F18 asap! 
So they called you...to solve their major problem.
How was the Wildcat concept born?


MF:Hobie Cat had been thinking about a new boat already for a while.
In 2004 they probably had some doubts and in 2006 they were sure that their boat was outdated. However, they waited, because they first wanted to see what the others were doing. In 2008 Hobie contacted me for a new F18 design.

They were not at all in a rush and they gave me all the time that was needed to design a new boat. The design brief was very simple: A boat that is capable to win the F18 World Title. They actually gave me a blank sheet of paper and there was absolutely no constraint to use any parts from the Tiger for the new boat.

We had several design meetings with top sailors like Jean Christophe Mourniac, Mitch Booth, Darren Bandock, and Glen Ashby. They gave valuable input on several aspects of the boat, and this collaboration surely helped to improve the final version of the boat. Overall working with Hobie on this project has been a very good and pleasant experience.

CSN:What´s the story behind this extreme bow-rails concept?
MF: The idea is to force the bow wave to detach from the hull at a certain point. Thus the bow rail reduces the dynamical wetted surface.

The bow rail concept came as a result of the numerical simulations k-epsilon did on the project. The results showed, that the bow rails reduce the overall drag, it they are properly placed and if they have the right size. Without numerical simulations I never would have dared pursuing this path.
The raked bow is simply to reduce wetted surface and to reduce the windage of the windward hull.
(CS- Check post of January 2009 on Wildcat rails, actually Martin told me he read that post at the time and was that glad I didn´t say it was for generating "lift" or solely for strenght as expressed in many other forums..)


- CSN:More volume is the way to go in the class looking at latest designs, one main characteristic of the Cap, that was addresed with their new C2, was margin to push hard downwind (this even said by AHPC) the Wildcat seems to have more volume than the Capricorn, but still hasn´t the same margin as say , the Infusion or Shockwave. -This is a compromise you decided to stand (reduced bow volume compared to Infusion)? as opposed to excel upwind? 

MF:During the development of the boat we also tested wider shapes.
The results of the RANSE simulations, however, showed, that there was a drag penalty especially upwind if we were going for wider hulls.

After discussion with Hobie and with some of the top sailors we decided to go for a moderately wide shape. The idea behind it is that many regattas are decided on the first windward leg, so being quick upwind pays in general.

- CSN: Other key and distintictive feauture of the Wildcat is her Foils, quite narrow but proved be quite efficient. You've developed your own foil section, for what 'DAG' stands for? and is the Wildcat using them? MF:Yes, I use my own wing section. It is a section with a pronounced hollow at the back. The difference compared to most other hollow sections is that this one was designed for a turbulent boundary condition and not for a laminar one.

Wing sections that rely on a laminar boundary layer may show rather poor performance if the incoming flow is already quite turbulent. In that case the transition from laminar to turbulent boundary layer is very early and the rear part of the laminar section does not work as it is supposed to do.

On small boats sailing at relatively high speed in rough conditions (wave induced turbulence) laminar sections are in my opinion not appropriate. DAG simply stands for “daggerboard”. The mk-I version of the section was designed for an A-Class daggerboard.

Today there are 5 different versions of the section (mk-I to mk-V). Different DAG sections have been used on the Capricorn, Wild Cat, Groupama-2 and Groupam-3, Sodebo, Banque Populare-60 and on BMW Oracle.

- CSN: Last year the Wildcat almost grabs the wc with Mischa on her 1st try, with months of the actual launch, quite a challenge for any brand new boat. How did you felt about time frames the Hobie Pro team had for the necessary adaption and post tuning for a new design? MF: Well the first boat hit the water in January 2009. Hobie and especially Mitch Booth did a very good job in bringing the boat up to speed in a relatively short time, but it nevertheless took a while – which is normal. Between the Tiger and Wild Cat the mast and rig changed completely, which explains the initial adaptation period.

- CSN: This year the Wcat teams are looking the fast and comfortable with the boat after a full year after the launch, did the boat had any change on design, or as I assume, it was just more hours to sail and fine tuning? MF:No, there were absolutely no changes.

- CSN: You are now also involved with the Sail Innovation project, this is in a personal basis right? MF:Yes, I got in contact with Alex Udine, the owner of Sail Innovation. He invited me in February to come and see the team in St. Malo. It was a very pleasant meeting and we decided to stay in contact. I am helping the team a bit in fine tuning the boat, but beside that Alex is doing all the sail development work for his campaign. I am very pleased to work occasionally with Alex Udin, Olivier Backes, Arnaud Jarlégan, Fred Le Peutrec (whom I alredy know from Groupama), Thibault Vauchel. I think that Alex is a very talented sail designer and he has put in place a very nice group.

- CSN: Future of the F18 designs? Any room to refine anything else within the actual rule? A-Class is more open and a lot is going with them. MF:Well, the obvious thing would be foils, but unfortunately that is forbidden. 15 years of development went into the class and finally we all ended up more or less in the same corner of the box rule – wide hulls with moderate rocker. Of course there is always way for improvement and for sure the Class will continue its development, but I think it will become more and more difficult to get an edge on the existing boats.

Olympics:

CS-Which boat should be used? Tornado, any current F18, or a special new design created for the games? MF:The Tornado is a nice boat but the design is no longer up to date and I think it is time to look for something new.
The F18 is a very active Class and choosing a current boat could be a solution. In that case I have (of course) a strong preference for the Wild Cat. On the other side I think a boat with foils would be nice. So I think an F18 like boat with foils should be used for the games in 2016.

I think 18 ft with a beam of 2.5 m would be a good choice. Transport is much easier than with a wider boat and such a boat would be significantly cheaper than a 20-ft boat. I would also like to see the weight come down a bit, but not to extreme levels. I reckon a weight of around 140 kg would be a good compromise between performance and cost.

CSN- Current and Future projects you are working?
MF: I am currently working full time on the Volvo Project for Franck Cammas and his Groupama team. That will keep me busy for a while. Beside that I am surveying the construction of a 40-ft racing trimaran that is currently under construction in Noumea for a private owner. It is basically a scaled down version of the ORMA-60 boats. It is capable to ocean passages (New Caledonia to New Zealand or to Australia) and it is also very exciting to sail it inshore. Furthermore I am working on my foiling A-Class catamaran. I use this boat as a platform to test a different foil concept.
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Copyright Catsailingnews---
To contact Martin Fischer: martin.ncl (at) gmail.com

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