A new mini

[nemo]

HI,
I'm working on a new mini (in my free time), and would like to get some comments from this forum.

http://album.foto.virgilio.it/bluoltremare78/862782


Some number:
Draft Amidsh. m1,949
Displacement kg986
Draft at FP m1,923
Draft at AP m1,976
Draft at LCF m1,956
Trim (+ve bow down) m-0,053
WL Length m6,460
WL Beam m2,163
Wetted Area m^2 10,328
Waterpl. Area m^2 8,642
Prismatic Coeff.0,404
Block Coeff. 0,035
Midship Area Coeff. 0,093
Waterpl. Area Coeff.0,621
LCB to Amidsh. m 0,569 Aft
LCF to Amidsh. m 0,763 Aft
KB m1,841
KG m1,828
BMt m2,369
BML m18,342
GMt m2,382
GML m18,355
KMt m4,211
KML m 20,184
Immersion (TPc) tonne/cm0,089
MTc tonne.m0,028
RM at 1deg = GMt.Disp.sin(1) kg.m41,004

Weight of the bulb is 260kg, sail area is: main:30m^2, jib:12m^2
Now I'm designing the rig.
The boat has got canting keel (70°overall) and 2 asymmetrical daggerboards.
Thanks for your comments
Stefano

[doesitfloat]

I like the design looks fast. Here are a couple of coments I thought of.

1. Chine
What would happen if you put a hard chine in the aft end. Since this is a smaller version of the open 50 / 60 It would not help those big boats with a chine, But this is much smaller. It would flatten out the back giving more planning surface. Up wind it would be so far back on the waterline it shouldn't affect it much. This is coming from 49'er experience where digging the chine into the water helps at the start and in other low wind boat handeling manuevers.

2. Swept foil
Looks really cool but wouldn't it be easier to build and operate if it was strait. And able to change angle of attack. The ORMA 60's all have the articulating centerboard now, I race on a older Formula 60 we use a wood wegde to add 1/2 a degree to our centerboard and it makes a noticable differance.

Nice boat though.
Cheers

[nemo]

Originally Posted by doesitfloat

I like the design looks fast. Here are a couple of coments I thought of.

1. Chine
What would happen if you put a hard chine in the aft end.

Never thought about that, sounds interesting..

Originally Posted by doesitfloat

2. Swept foil
Looks really cool but wouldn't it be easier to build and operate if it was strait. And able to change angle of attack. The ORMA 60's all have the articulating centerboard now, I race on a older Formula 60 we use a wood wegde to add 1/2 a degree to our centerboard and it makes a noticable differance.

Nice boat though.
Cheers

I put the swept foils for an interior arrangement problem: I prefer to have more free space afterwards the mast, but I still need lateral area after, so here comes the swept foil.
Did you see the 2 foils on the bow? I put them to prevent nosediving, which is very common on this kind of boat. what do you think about that?

[DaveB]

Is the Cp low or is it typical for these type of boats?

I thought a good target was 0.55 +/- 0.05... smaller for light wind, bigger for heavy...

Cheers,

Dave

[nemo]

Yes sorry, some of the coefficients above were wrong!!
So the real Cp is 0.545, while Cb is 0.350.
The wetted surface also is wrong, because it was calculated with the keel. Without it, the wetted surface of the canoe body is 8.97 m^2

[nemo]

I developed my little design a bit more.. you can see it on
www.delledesign.tk
I added a couple of GZ curves.. do you think they could be comparable with other mini curves? I've never seen one..