Monday, January 29, 2007
Better Buoyancy for Ballons, Blimps and Dirigibles
This may be old hat but it might be relevant to the geostationarybananaovertexas.com project. If I have money for patents anytime soon, it'll go to other patents, but if someone else wants to invest, let me know.
Self-Contained system to replace ballast or gas-release - or other means of changing buoyancy and altitude in lighter-than-air balloons or dirigibles
Russell Johnston, PhotoperiodEffect.com
August 10, 2001 version - last revised January 29 2007
Proposed Provisional Patent Application
Examples of applications:
Dirigibles and other shaped inflatable lighter-than-air (or partially lighter-than-air) devices are being reintroduced as lifting devices (SkyCat of Cardington, England, CargoLifter), tour vehicles (Zeppelin-NT, in service), and proposed as more ideal "cell-phone towers" hovering high over cities (Sky Station International of Washington, DC). As well, NASA plans a balloon expedition to Mars.
Advantages:
A self-contained system which did not involve the taking on or discarding of ballast, or the releasing of gases in order to reduce buoyancy would be more convenient and practical, particular for frequent use. For example, the proposed CargoLifter CL 160 Airship heavy lifting system would have the craft taking on large amounts of water ballast whenever it released a large load. This might well make releasing such loads in remote areas or to mountain tops inconvenient. Repeatedly picking up and releasing loads by such means might be extremely inconvenient. The alternative of gas release, particularly of Helium, is very expensive. In sum, ballast or gas-release systems are highly inconvenient, particularly for repeated use. In the case of the NASA probe, they would not be practical for any lengthy exploration of Mars without a means of adding ballast or gas in situ, yet to do without any means of changing altitude in order to descend to examine the surface closely would obviously limit the mission's usefulness.
The Proposed Device:
In this system buoyant gas is converted from having lift to becoming weight, and therefore ballast, without loss, by compressing it in a container within the craft. It is re-converted to lift again by releasing it from that container into the general bladder or gas envelope it came from. This would necessitate pumps/compressors and the use of some energy. However, it would offer very fine control of the craft's lift and therefore altitude, without any loss of ballast or gas, and the process could be repeated as needed. In previous times, the canister to contain the compressed gas, and perhaps the pumps needed, might have been prohibitively expensive. Modern materials have changed this equation, probably enough to make this a weight-economical secondary system or primary system for altitude control (or to vary the weight-lifting capability) of such lighter-than-air craft. In the case of the NASA probe, such a device could be designed to be discarded at some point to allow higher-altitude surveys, if desired.
It might be necessary or convenient, for non-rigid airships or otherwise, to provide secondary bladders which would operate on these principles so that at least one portion of the structure remained rigidly inflated, even when such buoyancy bladders are deflated.
A better system than the above might be to provide a second "ballast air" bladder inside the main (buoyancy) bladder with a connection to the outside air. (During a descent, for example) air could be pumped into this bladder to replace any buoyant gas that was being compressed, adding a minor amount of weight and more importantly, maintaining the main bladder's pressure at a constant amount. When more buoyancy was wanted, and buoyant gas released into the main chamber again, air would be pumped out/released from the secondary or "air ballast" bladder. Such a system might be considered a bit more closely analogous to the way submarines work, and might be especially useful for shaped balloons or airships without a rigid frame.
Note, in any case, that only a portion of the buoyant gas needs to be compressed in order to alter the buoyancy of the craft overall. In order to vary altitude for a craft whose weight is being held constant, perhaps only quite a small portion - reducing the weight of such a system.
Prior Art:
(This is not intended to be exhaustive, and health and other work have prevented a proper search.) Fish have air bladders that are not wholly unlike such a device, and of course, submarines also vary their buoyancy, and by similar means. Air is used to displace water from the surrounding ocean in buoyancy tanks in order to make the machine more buoyant; and air is released or removed from buoyancy tanks, being replaced by outside water, in order to allow the machine to sink. So far as I know, a way of applying such principles to airships has not been introduced, however. Nor do I know with certainty whether submarines re-compress air from their buoyancy tanks instead of releasing it. If not, that advance would fall under this idea as well.
Self-Contained system to replace ballast or gas-release - or other means of changing buoyancy and altitude in lighter-than-air balloons or dirigibles
Russell Johnston, PhotoperiodEffect.com
August 10, 2001 version - last revised January 29 2007
Proposed Provisional Patent Application
Examples of applications:
Dirigibles and other shaped inflatable lighter-than-air (or partially lighter-than-air) devices are being reintroduced as lifting devices (SkyCat of Cardington, England, CargoLifter), tour vehicles (Zeppelin-NT, in service), and proposed as more ideal "cell-phone towers" hovering high over cities (Sky Station International of Washington, DC). As well, NASA plans a balloon expedition to Mars.
Advantages:
A self-contained system which did not involve the taking on or discarding of ballast, or the releasing of gases in order to reduce buoyancy would be more convenient and practical, particular for frequent use. For example, the proposed CargoLifter CL 160 Airship heavy lifting system would have the craft taking on large amounts of water ballast whenever it released a large load. This might well make releasing such loads in remote areas or to mountain tops inconvenient. Repeatedly picking up and releasing loads by such means might be extremely inconvenient. The alternative of gas release, particularly of Helium, is very expensive. In sum, ballast or gas-release systems are highly inconvenient, particularly for repeated use. In the case of the NASA probe, they would not be practical for any lengthy exploration of Mars without a means of adding ballast or gas in situ, yet to do without any means of changing altitude in order to descend to examine the surface closely would obviously limit the mission's usefulness.
The Proposed Device:
In this system buoyant gas is converted from having lift to becoming weight, and therefore ballast, without loss, by compressing it in a container within the craft. It is re-converted to lift again by releasing it from that container into the general bladder or gas envelope it came from. This would necessitate pumps/compressors and the use of some energy. However, it would offer very fine control of the craft's lift and therefore altitude, without any loss of ballast or gas, and the process could be repeated as needed. In previous times, the canister to contain the compressed gas, and perhaps the pumps needed, might have been prohibitively expensive. Modern materials have changed this equation, probably enough to make this a weight-economical secondary system or primary system for altitude control (or to vary the weight-lifting capability) of such lighter-than-air craft. In the case of the NASA probe, such a device could be designed to be discarded at some point to allow higher-altitude surveys, if desired.
It might be necessary or convenient, for non-rigid airships or otherwise, to provide secondary bladders which would operate on these principles so that at least one portion of the structure remained rigidly inflated, even when such buoyancy bladders are deflated.
A better system than the above might be to provide a second "ballast air" bladder inside the main (buoyancy) bladder with a connection to the outside air. (During a descent, for example) air could be pumped into this bladder to replace any buoyant gas that was being compressed, adding a minor amount of weight and more importantly, maintaining the main bladder's pressure at a constant amount. When more buoyancy was wanted, and buoyant gas released into the main chamber again, air would be pumped out/released from the secondary or "air ballast" bladder. Such a system might be considered a bit more closely analogous to the way submarines work, and might be especially useful for shaped balloons or airships without a rigid frame.
Note, in any case, that only a portion of the buoyant gas needs to be compressed in order to alter the buoyancy of the craft overall. In order to vary altitude for a craft whose weight is being held constant, perhaps only quite a small portion - reducing the weight of such a system.
Prior Art:
(This is not intended to be exhaustive, and health and other work have prevented a proper search.) Fish have air bladders that are not wholly unlike such a device, and of course, submarines also vary their buoyancy, and by similar means. Air is used to displace water from the surrounding ocean in buoyancy tanks in order to make the machine more buoyant; and air is released or removed from buoyancy tanks, being replaced by outside water, in order to allow the machine to sink. So far as I know, a way of applying such principles to airships has not been introduced, however. Nor do I know with certainty whether submarines re-compress air from their buoyancy tanks instead of releasing it. If not, that advance would fall under this idea as well.
