Re: [PSUBS-MAILIST] Re: Dive planes

Paul,

I want to thank you and the group in general for these very informative responses. I will tell you that the learning curve in just a week?s time (Hurricane interruption included) has been quite steep. Let me respond to some of the things your posted.

?Some uninformed, unproven comments:?

I disagree; your explanation on the dive planes demonstrates a thorough understanding of the principals of hydrodynamics in this application, a very informed opinion, and thank you. This is the second time I am caught off guard regarding similarities to aerodynamics that I should have recognized, the first being Chip and his static pressure pitot tube system.

Your comments caused me to immediately realize the necessity of a locking mechanism (gust lock in aviation parlance) for surface travel. It is precisely this type of ?real world? experience sharing that makes this type of information group so valuable, and this before I have yet to pick up the first book!

?I was wondering too, have you talked to Pat Regan or looked at his Nautilus minisub? I don't think he gives a lot of technical design info on his site but he'd probably be happy to talk about it."

Yes, I have seen the minisub, and no I have yet to discuss it with him. For now, I am limiting my information gathering to this group and the Internet in general. I have spotted several modeling groups interested in the Nautilus but their interests lie in accurate reproduction vs. real world practicality.

As for the minisub, it started life as a typical 1 atm pressure hull from the beginning and was given the Nautilus attire later. I am sure that those of you with the Kittredge and other designs have as much to offer in terms of information on submersibles in general. At some point, I will approach him for his undeniable wealth of knowledge on the Disney-Goff design. For now, my questions are being answered here, or I am being given leads elsewhere.

Thanks again

Joe

From:  Paul Kreemer <paulkreemer@gmail.com>
Reply-To:  personal_submersibles@psubs.org
To:  personal_submersibles@psubs.org
Subject:  Re: [PSUBS-MAILIST] Dive planes
Date:  Fri, 28 Oct 2005 16:27:25 -0700

Some uninformed, unproven comments:

I'd say that in general as the size of the vessel is reduced the
relative size of the control planes will increase. The Nautilus
planes are low aspect ratio, longer than they're wide, so they should
continue to work at low speed. Similarly they might be a little
scary at high speed and would create a bit more drag than a higher
aspect ratio fin.

They're probably arranged roughly equidistant from the center of mass
and so should allow for gliding up and down while keeping the boat
horizontal. Actually controlling pitch would require differential
operation of them fore and aft.

I think the Kraka planes show a modification that you see on a lot
of low speed aircraft, that backward swept leading edge section may
have been added later to increase the area of the planes. Also a
swept fin like that does help prevent stalling so should keep working
at low speeds.

I was wondering too, have you talked to Pat Regan or looked at his
Nautilus minisub? I don't think he gives a lot of technical
design info on his site but he'd probably be happy to talk about
it.

Paul