Sonntag, 3. Juli 2016

2016 A-Cat Worlds Medemblik

crazy summer 2016 - most of the sailing I've done this year was during rain and bad weather - and it was the same in Medemblik :-)
Despite the bad weather we had a great week at Medemblik. The performance of the G7 with the new daggerboards is very good. Looks like we have the highest aspect ration daggerboard and our T-Foil Rudder which is height-adjustable while sailing really helped in the drifting conditions. Also the membrane sail was very polyvalent - it goes really well in drifting conditions and also if the breeze is up. It is a pitty that the top guns on the G7 were not there like Sascha and Stumhofer...
So not much to add - it seems that the "big jump" the class made with downwind foiling is over and there are only small steps to go forward (which is great for the Class I think...). Upwind foiling is now possible but the conditions in which it pays off are very limited - many times it is like trying to fly downwind when there is not enough wind - you go just nowhere.
In the end, the best sailor with the most time on the boat wins.

Results (Top 15):
NoSailnoNameScores12345678BoatSail
1NED 7Mischa Heemskerk, Foiling, -7,01111111(dns)DNA F1.Mischa Sails
2AUS 888Darren Bundock, Foiling, Master16,02211-11235Exploder D3Brewin
3AUS 4Steven Norman Brewin, Foiling, -22,0134526-81Exploder D3Brewin
4POL 1Jacek Noetzel, Foiling, Master23,0445-233322Exploder D3Brewin
5POL 15Tymoteusz Bendyk, Foiling, -27,04322-8754Exploder D3Bryt Sails
6USA 311Bruce Mahoney, Foiling, -34,035-666446DNA F1Mischa Sails
7NED 95Roeland Wentholt, Foiling, Grand Master36,0-156654573DNA F1Mischa Sails
8GER 14Bob Baier, Foiling, Grand Master46,0627878-98Scheurer G7.North
9AUS 14Adam Beattie, Foiling, -48,0124335-17147Exploder D3Brewin
10DEN 1Thomas Paasch, Foiling, Master59,056841015-1811NikitaNorth.
11POL 41Jakub Surowiec, Foiling, Junior64,01475713(dnf)612Exploder D3Bryt sails
12SUI 1Sandro Caviezel, Foiling, -70,077124121216(dns)Scheurer G7Landenberger
13NED 28Pieterjan Dwarshuis, Foiling, Grand Master72,0171910141110(ufd)DNA F1Mischa Sails
14NED 888Carolijn Brouwer, Foiling, Female76,06811-221510179Exploder D3Brewin
15FRA 2Emmanuel Dodé, Foiling, -77,05511121813-2113DNA F1Mischa Sails

Some pictures by Aron Steinmann/Scheurerwerft:








Mittwoch, 25. Mai 2016

Swiss A-Class Nationals Maccagno

for pictures and informations check blog from Martin:
catsailingnews

After the event, we went out for a fotoshooting session, check pics below:












Dienstag, 1. März 2016

Update (February 16)

testing is going on - check out Brewin sail on top of Landi Membrane from last year:



and a new video: it is a little bit long but "un-edited" during the runs:
(setup: old tramp, old sail, new foils)


Donnerstag, 24. Dezember 2015

Best Christmas Gift Ever :-)

My intention was to continue with some recaps of the past sailing season and the development we did so far but there are some news I would like to share:
After the worlds in Punta Ala we decided to develop a new daggerboard. Until the worlds in Punta Ala there was nothing available thas was objiously faster as our J-board. But we already considered that the DNA guys are doing really well. One year ago in Maubuisson we could keep up with them but as the conditions in that time were really unsteady and gusty it was not easy to compare. Furthermore the water was really flat all the time which was good for our foil. Later in Punta Ala we noticed that especially in mid range conditions with building waves we were a little bit behind. This is based on our shorter daggerboard compared to others. If the breeze and waves were building further up the differences were getting smaller as in strong breeze conditions everybody is struggling to keep the foils in the water (as also do other boat classes as f.e. the Moths). We also noticed that in the lower wind range we were doing really well and we could keep up with classic C-board boats which is really an advantage. However, it seems that the new riggs are working so efficient that you can foil almost in every race that is held in regular conditions (wind > 5 knots).
Based on this analysis, the design goals for our new daggerboards were:
- improve stability
- keep light wind performance
- more lift (for light wind foiling downwind and upwind foiling in mid range conditions)

Improving stability and getting a longer foil was going hand in hand by opening the angle of the lifting surface a little bit. If you take into account a force equilibrium of an A-Class platform using both daggerboards for foiling you can find an construction angle for which the leeward foil has a force-minimum to produce  (boundary conditions: foiling on two foils). With CFD simulations we took into account deformations (and therefore change of the angle of the lifting surface) to get the right angle while loaded.
Next design goal was to keep the existing light wind performance while increasing lift. The light wind performance is best analysed looking at the upwind performance in floating mode. We were playing around with toe-in angles and symmetrical and asymmetrical sections. It was a little bit like finding a needle in haystack to find the optimal solutions for upwind sailing and downwind foiling. The tricky thing is to get everything sorted out so that the daggerboards are pushing against each other on the downwind and so creating a big "V" which gives you great stability. The sections of the board have to be carefully selected so the windward foil doesn’t produce a force while sailing upwind to not loose any righting moment.
To cut a long story short, we think we found the solution. Just to give you an idea of how sensible the whole system was: During development we started with the daggerboard “01a”. Every time we changed the outline we alse changed the number . Whenever we changed the section we also changed the letter. The final solution has the internal number "14o" ;-)

so, here some pics:




Development was quite time-consuming which resulted in not being on the water since the worlds in Punta Ala. We took advantage of a little bit wind last Monday to go on the water for the first test. We were still sailing with classic mains and tramps so we could compare only the old daggerboard to the new one and the results were really convincing. We started in a very light breeze (below 4 knots) where no performance difference was noticeable. As the breeze was picking up a little (8 - 10 knots) we find a performance advantage of the new foil compared to the old one in terms of pure speed, controllability and handling. Upwind in classic floating mode we found no performance difference, so we tried upwind foiling (which was not efficient with the old daggerboard). It was possible to get the boat on the foils and the feeling was really great and easy. It seems definitely the way to go and I'm really looking forward to get things sorted out for upwind foiling. I think bringing down the point of sail force application using the new style decksweeper sails is the obvious next step.






next steps:
We will run a few more tests and improve some details for final production solution of the daggerboard. We should be ready for production mid February. I will keep you up to date. Next test will be together with Sascha who was developing in the meantime together with Felix & Landi the LOD decksweeper and tramp.


So, we (Daniel, Andy, Aron and the Scheurwerft crew and myself) wish you a peaceful Christmas season and a good start to a promising year 2016.


cheers
Sandro

Donnerstag, 19. November 2015

2015 recap (part I)

yes I know... there was not much info in the last time on this blog but there was too much work so that the blog got a little bit neglected.

So here we go with the recap 2015 (part I):
- Our first built rudder had some ventilation issues. Ventilation was not considered in our CFD simulation as it is a very complex topic and to simulate it properly you need a lot of resources and time... but after building expensive moulds with a section that was critical for ventilation (as we noticed after the first test rides) we had to rethink about this topic. We modified the simulation to include the models needed to simulate ventilation. As a reference, we always had the Rudder from 2014 (the short one from Jakub) which was working really well:



 Here you can see the reproduced ventilation problem on our first built rudder:


and some animations:





It was a very time-consuming experience but we learned our lesson and we went for another one. Finally, we got our new rudder working really well, there is no more ventilation and because of the extra length you're never running out of rudder again ;-)

Finding the right section for the rudder was only one issue of the whole rudder-project. In a next recap I will give you some informations about rudder blade and rudder case stiffness, ruder hangings and height adjustment (while sailing) of the rudder blade.

So stay tuned.