Re: [PSUBS-MAILIST] Dive planes

Glen,

While some aspects of aviation carry over to PSUBs, the much greater density of the fluid medium changes how fluid dynamics apply. A typical fin for a PSUB just because it doesn?t have laminar flow does not mean that it is stalled otherwise a rudder or a fin keel on a boat would not work. Yes at higher angles of attack, they will stall but noting we should see in a PSUB.. The greatest amount of hydrodynamic development work with the K-350 should be focused on changing the shape of the forward main ballast tank to improve towability and minimize the forces while towing that want to drive the bow down. If I remember correctly, at speeds less than 3 kts. (K-350 speeds) fairings do not do much for the reduction of drag. Maneuverability of a helo at slow speeds does not have correlations with maneuvering a K-350.

Reserve buoyancy of the K-350 is another issue that could be improved.

R/Jay

Resepectfully,

Jay K. Jeffries

Andros Is., Bahamas

Save the whales, collect the whole set.

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of glen brown
Sent: Sunday, September 13, 2009 5:56 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Dive planes

Any kind of addition such as wings ect regardless of design create drag which equates to more energy spent slower speeds and less monouvability only addition that I can see helping at our speed is the addition of fairings to try and streamline our existing designs why would one want wings(fins) when one has no laminar flow over them that means they are permanently stalled in other words not functioning I remember when I used to fly a Cessna 210 I owned a couple of years ago on circuit one of the things one would do is deploy the landing gear it used to feel as if you put the brakes on I now fly only helicopters and at slow speeds rely on Thrust I know water is a different medium but I think the design of most psubs are not exactly designed to be speedsters after all you not exactly cruising hundreds of miles but the very fact that they can hover and are slow make them very appealing to me flying fast through the air is boring but capturing game or rescuing someone in the mountains is great besides most a/c are so designed that if you let go of the yoke it will fly its self how boring . at present airbus is training special dogs to fly in the cockpit with there pilots and they are trained to stop the pilots from touching the controls the pilots sole purpose in future on fixed wing will be to keep the pax happy joke .He;licopters are difficult to handle at low speeds which I am sure my K350 will also be especially in open seas but I think regardless of how unstable it may be with practice one should be able to master it where as a stable boat will be easier to control but harder to manouver.Without proper research any wing design could make the boat uncontrollable at slow speeds.This Is only my opinion I could be wrong.

All the best

GlenSA