Everything Old is new again - Flettner Rotor Ship is launched

Thanks for the Nile River clip there Kommando - very interesting. I wonder if they have a web site with the details or something like that.

I got your message about a scale model flettner - sounds like a good project. You ought to open a new thread under the Projects category, so other interested parties can contribute.

There is one other Flettner project there at the moment

http://www.boatdesign.net/forums/projects-proposals/collapsible-flettner-rotor-project-50587.html

 

I'll have more to post at collapsible Flettner rotor project soon. Researching an idea.

 

Rotor company in the USA / Bremuda

Just came across these guys, it looks like a collapsible flettner that goes below the deck. Dosent have the potential to be damaged as the Monorotor, and Thiiink / wind again or the Norsepower versions. gets off the deck when running directly into the wind, or for cargo loading. Class approved. and points unlike the kites. pretty cool.

Magnuss.com

 

Great find there WW.

Their news links were really interesting too

http://magnuss.com/news.html

 

http://poisson.me.dal.ca/~dp_13_16/index.html

Design of a human-powered rotor ship.

Patent regarding the E-SHIP 1: http://www.faqs.org/patents/app/20130233223

 

Very interesting project, thanks.
I've quickly gone through the reports they have published, and it looks like they have taking this task very very seriously. Can't wait to see the result of full-scale tests.

I don't like the idea of the rotor support disc with holes (page 33 of this report: http://poisson.me.dal.ca/~dp_13_16/Group 12 Winter Design Report.pdf). It would be imo better if they had completely sealed the rotor volume with full discs, to have a buoyancy in case of capsize.

And in fact, it apparently gets swamped during the tests: http://poisson.me.dal.ca/~dp_13_16/Group 16 Design Verification Report.pdf - page 10.

And then... Well, using FEM for this analysis (and also how it was done), makes me smile a bit:



For the rest, a very nice and interesting project. Will follow it.

 

Even if the project isnt a total success, i am sure the experience of developing a formal project will be a great aid to these guys in their professional lives.

Their choice of a Laser for the carrying platform is ... um .. interesting. The weight of the construction will be critical for stability.

This is why they are not sealing the cylinder ( Page 20) . If they used a lightweight foam for the cylinder instead of the polycarbonate, they would get plenty of buoyancy in a capsize, along with quick draining. The weight and complexity of a sealed cylinder would negate the setup and transport benefits they are seeking.

My gut feeling is that the multiple pulleys is a bad idea, too much friction. They might do better with a commercial right angle reduction arrangement like the human powered projects do, using steel shafts up to the bottom of the rotor. - EDIT : ah, I see they did that on page 55

In fact, it looks like they tested the whole thing in a pool on page 55 - but no photos, and they decided not to test it on open water.

I am confused by the comments on page 56 and 57 - it sounds like they actually built one, but the reference
http:/commons.wikimedia.org/wiki/file:magnus_effect_at_flettner_rotor_boat.svg

does not exist.

A bit of a mystery in all


edit

HEEY - the pictures of the results

http://poisson.me.dal.ca/~dp_13_16/Group 16 Design Verification Report.pdf

Edit: 3 - they couldnt get 240 rpm rotation , only got 90 rpm, page 9 :-(
No wonder they didnt go to open water

 

Thought I would physically put the results into this thread in case the link disappears in future

 

They would need a disc on top of the rotor for it's better performance.
And why they came up with such complicated gearing anyway? Wouldn't it be easier if the man simply could sit at the stern & pedal the thing like a bicycle?

 

The did consider it in the plan but the Thom fences were left out due to installation and transport concerns

Thats what I said, "that the multiple pulleys is a bad idea, too much friction". I bet that's one of the reasons they couldn't get it to rotate fast enough., That and the simplistic bearings on the mast.

All that professional planning, and they ignored the bleeding obvious.

 

In addition, spinning the rotor at high rpm requires more horsepower than two men can produce according to daiquiri's calculations for the rotor designed on my thread.

 

I have seen calculations in the past that proposed that it would be possible for manpower to do it, but the articles are lost in time. Joseph Norwood was the guy I was corresponding with. I must also get his book "Twenty-First Century Sailing Multihulls (AYRS #120)"
http://www.amazon.com/Century-Sailing-Multihulls-Joseph-Norwood/dp/B0034UN0NM

or a copy from
http://www.ayrs.org/ayrslist.htm

I have attached an article of his that I haven't read totally where he does the math.


I would expect it would be a task like propelling a pushbike up an incline, and a couple of selectable gears might be a big help.

Certainly, an efficient drive train and bearings would make all the difference

 

I got this email from office@ayrs.org




AYRS Publication No 120 (21st Century Multihulls by Joe Norwood, 2vols) is not available for download, but we can post you a copy for GBP7.00 including surface mail. Airmail to Australia would be an additional GBP3.00.

If you would like a copy, the easiest way of paying for it is through PayPal, making your payment to office@ayrs.org. If you don't already have a PayPal account, then they will charge your credit card. (They will also I believe take payment in Aus$, and convert it for us)

Please make sure you give PayPal your full mailing address, as we are required to send it to the address they give us, (which for a card payment will be the address to which the card is registered)

Thank you and hope to hear form you

Regards
S Fishwick
Editor
Amateur Yacht Research Society
--
email: editor@ayrs.org
WWW: http://www.ayrs.org
Postal address: Amateur Yacht Research Society, BCM AYRS, London WC1N 3XX, UK

The Amateur Yacht Research Society is a not-for-profit limited company
registered in England, Company number 785326, Educational Charity No 234081
Regd Office: 9 Lynton Road, Thorpe Bay, Essex SS1 3BE.




I'm going to get a copy, since its pretty inexpensive, It has a lot of info on building rotor boats.

 

So, here's a question: if since a rotor gives no propulsion to the boat unless it is rotated and since rotation is human powered then for legal purposes would this be considered an HPV or sail?

I ask in relation to Texas not requiring registration of HPVs no matter their length (meaning one could, in theory, have a relatively long slender stabilized monohull and still have it treated as their canoe would be).

 

Actually, it would require both human power and wind. Neither of these power sources alone would be sufficient for producing thrust - their simultaneous interaction is necessary. So, that would make a hybrid system.

Don't have the answer to the legal part of your question, though...