Student Design, critique?

vling · 10-06-2009, 05:01 PM

Hello YF,

My name is Vaughan, I'm a transportation design student working on a yacht for my term project, and was hoping to get some constructive feedback from the knowledgeable folks on YF. The design is ~320 ft length, inspired by the Greek Trireme, using sail (Dynarig) and solar power. Above deck is supposed to be mostly open air with large overhangs for shade. My main concern for the design is: Will the long nose or keel placement be problematic for balance/handling of the ship? The design is still in progress, so any feedback is greatly appreciated!

Thanks, Vaughan

84far · 10-07-2009, 05:15 AM

Vaughan,

first thoughts are 'star wars'

. second, instead of having the single blade (keel) in the middle, have two seperate blades, still have both blades connected to the bulb. the New Zealand America's Cup team tried it (concept) one year... not to sure if it works, but it would look good... unless thats the traditional/modern look your going for?
theres no reason for that bow not working, u would just have to be careful with it.
if u made it a planning hull that would be nice.

overall, pretty cool imo

far

AMG · 10-07-2009, 05:35 AM

I have just one question, which way is it going..?

Henning · 10-07-2009, 06:22 AM

Quote:

Originally Posted by vling

Hello YF,

My name is Vaughan, I'm a transportation design student working on a yacht for my term project, and was hoping to get some constructive feedback from the knowledgeable folks on YF. The design is ~320 ft length, inspired by the Greek Trireme, using sail (Dynarig) and solar power. Above deck is supposed to be mostly open air with large overhangs for shade. My main concern for the design is: Will the long nose or keel placement be problematic for balance/handling of the ship? The design is still in progress, so any feedback is greatly appreciated!

Thanks, Vaughan

The greater problem with the handling of the vessel will be the balance of power around the longitudinal center of balance. The way she is rigged, she will always want to drive off the wind meaning she will always need to have helm applied to keep her nose up which will cause drag until the rudder stalls without her being pointed up very high at all. As for solar power, are you talking photovoltaic or thermal transfer/steam? I wouldn't personally bother with either. Do a bit of research on a ship Phillipe Cousteau built some time back with a rotary vane turbine sail which drove the props. Rather than harnessing the wind and redirecting it (with the restrictions of aerodynamic foils and stalling) for propulsion under Newtons 3rd law, the wind spun a vertical turbine which went through a gear box to the shaft. The variable position of the turbine housing and stators allowed the ability to sail at any point of the wind.

84far · 10-07-2009, 07:27 AM

what about a forward canard, standard centerboard/bulb and rudder at the back?

far

Henning · 10-07-2009, 09:51 AM

Quote:

Originally Posted by 84far

what about a forward canard, standard centerboard/bulb and rudder at the back?

far

What purpose would the canard serve? I know what it is and what it does, but why use one? It's just extra drag. Better off balancing the drive IMO.

84far · 10-08-2009, 12:15 AM

its just a suggestion, and well it could also act like a second rudder, given the length of the boat, and the length of the keel it may need an extra hand turning (tacking).
u could also reduce the size of the rudder cause u have the canard up front (reduce drag). and due to the depth of the keel, she wouldnt have to much under the water when shes on a heel, so it could help there to? your thoughts?
and would u say this boat could use some more sail area and less bulb? thoughts?

far

vling · 10-08-2009, 12:46 AM

Thanks for the suggestions so far. I discussed the balance issue with my professor today and will be making adjustments to the proportions of the hull (shortening the "nose") and lengthening the rear, bringing the sails and keel more to the center. BTW he had trouble figuring out which direction it was going too, so hopefully the new proportions will help that.

84far · 10-09-2009, 08:25 PM

in the first pic the bow is on the left?

far

vling · 10-09-2009, 08:46 PM

bow on the right

NYCAP123 · 10-09-2009, 09:34 PM

Quote:

Originally Posted by vling

bow on the right

At first glance that's what I thought and saw Star Trek's Enterprise as inspiration. Then I looked harder at what looked like a bow sprit and said 'no, that has to be the bow'. Radical. Should be interestting to watch it evolve.

84far · 10-12-2009, 07:40 PM

bows on the right, thank god. the balance should be ok. i would like to see more sail area though.

i was thinking more a 'Naboo Royal Starship'. and if u could do all the portholes with the same tint as the hull, that would look pretty **** sexy to... your project though

far

vling · 10-12-2009, 10:56 PM

84far - An earlier version of this looked very Nabooey, but got Xed for practicality and more greek trireme looks. Also, can you explain what bulb is? (more sail less bulb)

84far · 10-13-2009, 04:32 AM

vling.... WOW! out there!... ok, a little to much sail area

the 'bulb' is the lead weight at the bottom of the centreboard. and basically if u make the sail area larger and less 'bulb', u will find a happy medium as far as boat speeds, etc goes. but thats more for the naval architect to work out.

far

Henning · 10-13-2009, 07:10 AM

Quote:

Originally Posted by vling

84far - An earlier version of this looked very Nabooey, but got Xed for practicality and more greek trireme looks. Also, can you explain what bulb is? (more sail less bulb)

Interesting.... I'm going to assume you haven't spent any time at sea. I think you have a bright future in Hollywood CGI. If you can make the designs into shiny metal objects, I think they may sell well as sculptures. As functioning vessels, not so much so. Study boat designs as they exist, and look at them through the centuries. You'll notice that there really isn't any radical change going on. The biggest changes are really in the details, because the major form issues are governed by the immutable laws of physics. The major form variables are all a trade off between drag and mission (volume, load carrying ability, range, speed, stability, sea kindliness...) requirements. As vessels for a "Transportation Project", I'm trying to figure out what missions the forms can fulfill. As art I think they are very nice, for a vessel though, form is driven by function to a great extent and function is determined by mission, so I suggest you first think about "What is this vessels job?" and with that you also have to consider "Where would the person with the mission she meets want to take her?" That will also dictate various limitations such as draft (might need to make that centerboard retractable) and even mast height for bridge clearance.