Search found 12 matches

by TheoSchmidt
Wed Sep 27, 2023 5:54 pm
Forum: Craft
Topic: solar electric propulsion of a power kat, 6.3 m
Replies: 19
Views: 16777215

Re: solar electric propulsion of a power kat, 6.3 m

Great, Heimfried! Is this now one of two catamaran hulls or have you changed to a monohull? Or is it a very narrow cat?
by TheoSchmidt
Sat Mar 18, 2023 9:38 am
Forum: Technical Papers for review and comment
Topic: Howard Fund
Replies: 38
Views: 16777215

Re: Howard Fund

Hi Alex,
This thread stopped just before Christmas 2020. Any more news or did you post it elsewhere? Did you now write it up as a submission for the Howard Fund?
by TheoSchmidt
Thu Oct 27, 2022 5:30 pm
Forum: Craft
Topic: A floating Gym
Replies: 1
Views: 2278

Re: A floating Gym

Yes, very interested! I was involved with a 12-person mechanically pedalled monuhull which worked well and a 12-person catamaran with pedal generators which didn't and was sent a project for a catamaran for 150 pedallers! All this stuff is on an old computer or on paper; I'll try to find it.
by TheoSchmidt
Thu Oct 27, 2022 5:17 pm
Forum: Craft
Topic: Holtom Foiler 21 - any information?
Replies: 1
Views: 2364

Re: Holtom Foiler 21 - any information?

I owned one for several years when I lived in Dorset, but sailed it only three or four times and capsized it once (in Portland Harbour), by bearing away too quickly. I have some photos showing the rigging (Michael Ellison supplied the sail!). This was one of Gerald Holtom's originals made of cold-mo...
by TheoSchmidt
Sun Aug 21, 2022 6:02 pm
Forum: Members Sales and Wants
Topic: Hapas free to a good home
Replies: 3
Views: 64435

Hapas free to a good home

Roger Glencross has a collection of Hapas or "Chiens de mer", made by Didier Coste and/or Stéphane Rousson (see http://www.seaglider.fr/Seaglider/Seaglider_History.html , http://www.seaglider.fr/Seaglider/Bienvenue.html , https://fr.wikipedia.org/wiki/Voilier_des_airs , https://www.bateaux.com/artic...
by TheoSchmidt
Sat May 14, 2022 7:27 am
Forum: Craft
Topic: solar electric propulsion of a power kat, 6.3 m
Replies: 19
Views: 16777215

Re: solar electric propulsion of a power kat, 6.3 m

In http://web.archive.org/web/20200710010007/https://data.umwelteinsatz.ch/IBS/propsim.pdf I describe my own propeller simulation program and the large propeller I designed with it, using a Clark-Y flat-bottomed foil profile. The slip is very small at the best operating point. I'll try to compare th...
by TheoSchmidt
Thu Apr 28, 2022 7:18 pm
Forum: Craft
Topic: solar electric propulsion of a power kat, 6.3 m
Replies: 19
Views: 16777215

Re: solar electric propulsion of a power kat, 6.3 m

OK, a one ton boat. Last year I did some model tests and calculations for a pretty basic 2.5 tonne catamaran, 7.5 m long with 0.75 m diameter cylindrical hulls, somewhat pointed at the ends (typical "party boat"). The total driving force was, up to 3.5 m/s, well approximated with the formula: Power ...
by TheoSchmidt
Sun Apr 24, 2022 6:44 pm
Forum: Craft
Topic: solar electric propulsion of a power kat, 6.3 m
Replies: 19
Views: 16777215

Re: solar electric propulsion of a power kat, 6.3 m

Two 1.4 kW motors are surely ample for slow cruising. Alex has mentioned the importance of the thrust rating. This is so fighting a heavy headwind and of course you will then also be pounded by waves. For normal cruising the thrust figure isn't important, as you will simply get the speed at which th...
by TheoSchmidt
Tue Mar 29, 2022 6:55 pm
Forum: Welcome to the AYRS Forums
Topic: This Forum is functional again!
Replies: 2
Views: 11098

Re: This Forum is functional again!

Thank you, John! What I've done so far is to delete the category "News", which had few posts, after transferring these to "Events @ other announcements". Further suggestions welcome. Also, we have a number of "spambots" as users. The don't seem to be able to do any harm, but I aim to delete them. Ge...
by TheoSchmidt
Sun Mar 13, 2022 10:02 am
Forum: Technical Papers for review and comment
Topic: Ultimate Sailing for Oldies
Replies: 5
Views: 10760

Re: Ultimate Sailing for Oldies

Thanks to your getting me back into the loop, Roger, I'm able to reply to you here! Hence we have a need for superlift by pushing forward the A-frame control handle, effecting a larger angle of attack, and producing a lift co-efficient of 2.0. A “B” bar would be better, enabling the Aquaviator to pu...
by TheoSchmidt
Sun Mar 13, 2022 8:30 am
Forum: Wind- & Water-turbines, Propellors, Human power
Topic: Faster than the wind??
Replies: 2
Views: 9239

Re: Faster than the wind??

Two more links:
https://www.lockhaven.edu/%7Edsimanek/m ... dwfttw.htm "DDWFTTW Vehicle Analysis" by Donald Simanek 2013-2017
http://web.archive.org/web/201109040025 ... nd.org:80/ "Ride Like the Wind (only faster)" by Rick Cavallaro 2011