Small, Unmanned Buoyancy Control Device
Small, Unmanned Buoyancy Control Device
(OP)
I need a small buoyancy control device which can fit into a 4 inch diameter cylinder. Once dropping the cylinder into the ocean, it needs to achieve nuetral buoyancy at a depth between 50-250 feet, stay there for some period of time (anything over a few minutes would work) and then come back to the top. Any ideas on how I could either create such a device, or purchase an already commercially available product that would work?





RE: Small, Unmanned Buoyancy Control Device
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RE: Small, Unmanned Buoyancy Control Device
Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website: www.oil-gas-consulting.com
RE: Small, Unmanned Buoyancy Control Device
TTFN
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RE: Small, Unmanned Buoyancy Control Device
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Small, Unmanned Buoyancy Control Device
Sonobuoys are meant to sink at the end of their lives rather than resurface, but the ideas are all there to adapt.
(as you probably already know, trying to hold set depth using any sort of close-coupled gas-filled buoyancy bag is very difficult. Any increase of depth compresses the gas, making the device less buoyant and tending to increase the perturbation - such static instability means you need a dynamic control system which is almost certainly more complex and expensive than you really want. That's why submarines usually rely on hydrodynamic surfaces to control their depth).
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RE: Small, Unmanned Buoyancy Control Device
There are other pop-up buoys using different approaches used for marine research. The problem with any of these type buoys is sizing the anchor line based on the free buoyancy of the device.
As I recall these research buoys were made by "Benthos".
RE: Small, Unmanned Buoyancy Control Device
RE: Small, Unmanned Buoyancy Control Device
At a trade show last week, I saw someone giving out keyrings. The twist was, each fob concealed an open ended polythene float and a mixture of acid and carbonate powders. If your keys fall in the water, the mixture fills the bag, bursts the fob open and floats everything safely to the surface.
Sweet idea - now all they need to do is find a way of stopping it going off in your pocket the first time you get gophered.
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