Thanks Doug for your comments, I can address a few of them right away:I was actually planning to have separated ballast, i.e. a fore and aft separation in the middle of the big ballast tanks.
The tanks on either side will be linked, so that rolling is not generated by an offset boyant force, although pitch trim can be fine-tuned depending on depleation of air tanks etc. Of course, I might end up adding forward planes anyhow.
Getting in and out will be through a hatch in the top (not for santas). There is enough ballast to give a freeboard of around 30-40 cm when loaded up (I estimate). I envisage that the frame extending out that back can also be used to attach boyant modules to fine tune ballast. The V tail is simply a cop-out to try to get some stability mostly against roll, since the projected resistive area against pitch and yaw is minimised for a 45 degree angle in the V and is maximised against roll. Since that part of the machine will be (probably) in more turbulent flow a small x-section is preferable. Furthermore, It will be entirely passive. Steering (yaw and pitch) is achieved by motors only. I wanted to get away from dive planes because I live in puerto rico... there are big walls that I want to be near and be agile at low speeds.
Since I am not using many heavy materials, that require much machining, I hope that it will be cheaper than the typical 1 atm sub. I think I am at more liberty to get things wrong and make a second attempt later on. I expect that it will be quite iterative.
Thanks again for your comments! Please let me know if I am proposing anything which cause your eyebrows to jump in confusion/hysteria/contempt/disbelief!
EM. DJACKSON99@aol.com wrote:
Greetings EMSlick looking design. Not the metal can I'm building :) You might consider reducing the displacement of the cabin in order to decrease the amount of ballast required when you convert to dry? Maybe you can use 2 canopies, one for hydrodynamics and the second for the air seal. Since you're going to operate shallow you may want to consider that light entering the top of the canopy will reduce downward visibility due to reflection. You'll need a forward ballast compartment too, or you'll have to add dive planes and be more like the Bionic Dolphin (www.bionicdolphin.com <http://www.bionicdolphin.com>) And you need some way of getting in and out without sinking once you strap on the ballast needed to be dry, because your canopy opening will likely be below the water line. Maybe inflatable pontoons or a small top hatch? The v-tail is cool and low drag but they require a mixer that will complicate the build some. Thanks for showing your design. I look forward to seeing more. Doug Jacksonwww.jackson.parcabul.com/sub <http://www.jackson.parcabul.com/sub>In a message dated 3/3/2004 8:10:40 AM Central Standard Time, emuller@naic.edu writes:Hello folks, Due to pressure from un-named folks here (i.e. gauge pressure), and the upcoming threat of competition by scubatron (i.e. absolute pressure), I have also posted some images of design plans for an ambient, dry machine on moki. I suspect I will take the construction in a two-step process, firstly by building a wet torpedo-like thing and checking how it all works, construction methods etc. Then I will cover it over and blow all the water out to turn it into a dry machine. Comments please?? EM.