F18 Open Project: Looks & CFD

Above and below some new renders I’m working on, click to HQ, I like the Luna Rossa style one, I will ask Max Sirena if they have some left for us! Also been working on a Scorpion logo, check below.

We’ve been working with the group in the background on the Open Project doing some initial CFD tests with my original cad that has a pretty standard rocker and no concave/negative section for a clean start.
The first test were good and now we are analyzing an aft negative section , recommended by the CFD guys and we will test that next.
I specially want to see how the Cirrus R rocker performs on CFD and what reference it can give us to see if we can implement it or not.
Seeing how ETNZ and OR are going that route, it is worth to take a look.

We’ve also make some foil tests and we are already targeting an specific section.

The initial goal is still there: Design an Overall Performer.
And as a secondary target I think there still some room to achieve the above (already done in the class) but going to a higher degree of evolution.

The best feeling I ever had on an F18 is with the Hobie Wildcat. The Infusion/Falcon got me the most comfortable ride even in 25knots.
The Infusion and C2 are well proven World title boats, and they they have the widest performance range in any wind from 4 to 30knots.

A perfect boat should have that wide range, plus the Infusion-Cirrus R-Phantom highwinds margin, C2-Falcon speed in the breeze & Wildcat unmatched sensitive response and glide. Didn´t sailed the Phantom yet, but the feedback I have, above 5-6knot is really good.(Look for a complete design featured Interview with Udin on the Phantom soon)

Another key aspect is handling, and it seems the Cirrus R has superlative points in this area on the breeze and deep chop.

But we don´t want a boat that aims to excel in a determined targeted condition with a known drawback in others, we want to cover the whole spectrum. After seeing all and sailed the majority, I can say there is still margin with current designs to put all the best features in one boat without giving away any compromise… hard task I know, but in the process the group will learn quite a bit.

The funny thing after all this design talk “balblab” is that the other day I raced the Tiger for the first time, a special Tiger with 4 Wildcat foils, and Mischa’s black Ullmans.
We were flying without any handicap whatsoever, we maintained speed and even got a 3rd among average mid fleet results.
You had to see the faces of some in the fleet…. it was by far the best feeling I
ever had in a regatta!

This tells a lot about the F18 and design in gral, specially what a good one the Tiger is. Will publish later more details as I want a good picture of Gonzalo’s Super Tiger.

Beyond this that also proves how good the class rules are, I really like being involved in another F18 project, learning a lot and hoping we can put some additional juice to the class and racing cat community with it.
More updates in some weeks.


7 Responses

  1. Unknown says:

    Fancy trying curved borads?

  2. Anonymous says:

    Martin please note that the Cirrus R rocker line appeared to be a dog in 5 knots conditions. We, less then average sailors, could keep up with NED007 in those conditions on a Wildcat with short boards! NED007 obviously disappered when the wind was 20 knots, but I think he does that regardless the boat….

    Dom

    ITA106

  3. CSN says:

    Hi Dom
    That is exactly the point I've adressed on the post if you read well.

    There are many factor like volume and cross section shape that affects in calm beyond rocker.

    So the idea is to see if some new specific features doesn´t add drawbacks. If they do, we will not use them.

    Last Arg Nats & recent BA Week here in Arg was dominated by a Wildcat with shortboards too.
    WC is clearly my favorite but I want to combine it with more error margin without giving away performance in 5 knots.

    And that is the tough part.

  4. Lucas says:

    Se lo ve muy lindo Martin! te tiro una razon del rocker negativo en la popa del cirrus R y otros barcos (volvo 70, open 60) segun Juan K, eso sirve para retrasar la formacion de la ola de popa, generando asi una eslora en flotacion "virtual" mas grande que la real. Se ve muy bien el CFD que le hiciste, que programa usas?
    Abrazo!

  5. Anonymous says:

    Yes Martin, I read again your article and it is actually clear, I'm glad you are going in this direction. I love my WC, great looking boat also but man, that thing it's a tough ba@#@##d with the kite up in anything above 18 knots. We don't dig it anymore in a straight line, but during transitions that is a whole different story..the smallest error in timing and you are going to drink..Also to snap daggers ain't fun either…

    Still in the Italian ranking list in the first 6 places ther'are 4 WC…very good crews BTW.

    Well we will build your hulls and cannibalize the Wild for mast and hardware!

    Great work from you

    Cheers

    Dom

  6. Anonymous says:

    Would love to see the photos of the Tiger with Wildcat foils. Hope you put them up soon.

  7. CSN says:

    Maybe I'll race it again this weekend, will try to get some of the "Super Tiger"

    If not, for sure for next Arg Nats in 2 weeks-.