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UNIVERSITY
of WASHINGTON - DEPARTMENT of AEROSPACE & MECHANICAL ENGINEERING UUV PROJECT
Autonomous
Boat Specification:
Body Type: Teardrop
Size (LxWxH): 2.80m x 1.00m x 0.40m
Body Size (LxWxH): 1.80m x 0.30m x 0.30m
Hull Material: Fiberglass
Weight: 52.00kg
Maximum Depth: 1,000.00 m
Dynamic Buoyancy: No
Self-Righting: Yes
Obstacle Avoidance: No
Endurance (nominal load): 7200 hours
Manufacturer Website: http://www.irobot.com/us/
The Seaglider Fabrication Center (SFC) of the University of Washington provides new Seagliders™, operator training, and glider refurbishment to internal (UW) customers. SFC is a division of the School of Oceanography, managed by Dr. Fritz
Stahr.
External customers can purchase the same from iRobot Corp. Maritime Systems Division - see iRobot Seaglider, which announced on October 26, 2009, the order from the University of Western
Australia for six iRobot Seagliders. This marks the largest single order of the iRobot Seaglider to date.
A glider recently set new time and distance-travelled-unaided-by-current records for an AUV. SG144, owned by Dr. Charlie Eriksen (UW Professor, Physical Oceanography), working in the NE Pacific, traveled an excess of 5500 kilometers in 292 days (9.5 months) and was recovered on April 4, 2010.
PLATFORM
SUMMARY - iRobot Seaglider™ - Long-range, High Endurance Unmanned Underwater Vehicle
iRobot designs and builds robots that make a difference. iRobot Maritime Systems Unmanned Underwater Vehicles (UUVs) includes the iRobot®Seaglider™ , a long-range, high endurance UUV able to perform a variety of environmental monitoring, data-gathering and surveillance missions for researchers, offshore oil & gas engineers, and military planners - all for a fraction of the costs of traditional operations.
Seaglider’s available buoyancy engines enable efficient and long-term missions while operating continuously between 20 m and 1,000 m. Able to perform and gather data throughout shallow and deep dives in a single mission, Seaglider receives commands and transmits collected data on a programmable schedule to allow for continual monitoring and analysis and to guard against data loss.
Applications
-Physical, Chemical and Biological Oceanography
-Marine Environmental Monitoring and Time Series Data Collection and Reporting
-Hydrocarbon and Biochemical Detection
-Current Profiling
-Tactical Oceanographic Surveys
-Remote Autonomous Surveying
-Persistent Monitoring
-Persistent Surveillance
-Seaglider Development
iRobot has introduced new Seaglider fairings that significantly increases payload capacity while reducing total drag on the vehicle. The rounded and tapered or “ogive” aft fairings increase the Seaglider’s payload volume by 650% to more than 21,000 cm3 and doubles the payload mass carrying capacity to 4 kg. This development effort has led to the integration of more advanced sensors and opens the door to future integration efforts and missions.
Seaglider Sensor Integration
Seaglider has six payload ports that accommodate a wide range of sensors. The greater overall payload capacity of the new ogive fairing enables the integration of more numerous and larger payloads including the Nortek Current Profiler, Imagenex Echo Sounder, and pumped versions of the Sea-Bird CTD and Dissolved oxygen sensors.
Nortek USA and iRobot collaborated to develop and integrate a small, light weight and low-power consuming Current Profiler (CP) with the Seaglider. This capability enables the investigation and development of predictive models of ocean dynamics.
Seaglider supports a modified, compact echo sounder developed by Imagenex. This successful integration of the Imagenex Model 853 enables the Seaglider to perform long-term measurements of biomass in the world’s oceans to better understand the food chain. The echo sounder is able to store up to 200 days of raw data for download upon recover. The small size and lower power consumption is ideal for long-range, high endurance missions supported by the Seaglider.
More than 135 Seaglider UUVs have been delivered to customers worldwide, including the U.S. Navy, government agencies and research organizations. Seaglider has been deployed in a range of environments around the world, performing missions in the tropics and under polar ice, in freshwater and saltwater. In the future, Seagliders will be deployed on missions that last a year or more and cover more than 6,000 miles.
Industry Leadership
As a pioneer in the robot industry, iRobot’s goal is to drive innovation, serve as an industry catalyst and change the world by fueling the era of
robots.
With 20 years of leadership in the robot industry, iRobot remains committed to providing platforms for invention and discovery, developing key partnerships to foster technological exploration and building robots that improve the quality of life and safety standards worldwide.
The Seaglider was developed by The Applied Physics Laboratory University of Washington, and fielded in September 1999.
SEAGLIDER
and the Australian
National Facility for Ocean Gliders ANFOG
The Federally funded Integrated Marine Observing System
(IMOS) is network of sensors and data-information services which collect data needed by Australia’s marine and climate researchers. The observing system provides data in the coastal and open oceans around Australia and is a collaboration with the Australian marine science community.
UTS co-leads the NSW node of the observing system which is hosted by the Sydney Institute of Marine
Science(SIMS). Now fully operational NSW-IMOS is entering a new phase where researchers across multiple disciplines are using data streams to answer climate and ocean-related research questions.
SEAGLIDER glides slowly through the ocean propelled by buoyancy control and wing lift to alternately dive and climb along slanting glide paths. It dead reckons under water between GPS navigation fixes obtained at the sea surface to glide through a sequence of programmed targets. It transmits all data collected and receives commands via
satellite data telemetry, exposing its antenna above the sea surface for a few minutes between dive cycles.
SEAGLIDER range is sufficient to transit entire ocean basins in missions lasting many months while diving continuously to as deep as 1000 m. Gliders are routinely launched and recovered manually from small boats with a crew of two, avoiding costly reliance on ships. Operation costs a few dollars per kilometer of distance travelled to obtain high resolution profiles of physical, chemical, and bio-optical variables and estimates of depth-averaged current and surface current.
This seagoing glider is a particularly interesting piece of equipment. It is described as a “green robot” for the reason that it is powered entirely by the temperature fluctuations occurring at different depths in the water that it is used in. This gives it a limitless power source and an incredible lifespan. According to U.S. based researchers involved in the program:
They said the glider had crisscrossed the 13,000-feet-(4,000-meter-)deep Virgin Islands Basin between St. Thomas and St. Croix more than 20 times since it was launched in December.
And it could keep going on its own for another six months, the team at the Woods Hole Oceanographic Institution and Webb Research Corporation in Falmouth, Massachusetts, predicted.
ROBERT
D HUNT - PATENT APPLICATION
ABSTRACT
A sea glider having long narrow, high aspect ratio wings in order to produce a high glide ratio and having a hydro-turbine coupled to the sea glider to generate power via the movement of the submersible through water to harness kinetic energy from the forward motion of sea gliding. The sea glider is innovatively coupled to a surface sled that remains on the surface of the water to produce energy from wind via a wind turbine and solar energy via solar cells as the sea glider moves underwater. The sea glider and surface sled are connected via a tube that contains a bundle of individual lines for;
radar, GPS, and visual communications, to supply compressed air from the surface sled to the submersible for ballast control and for breathing by occupants, to allow spent air to return to the surface to a lower pressure, to provide warning notification at the surface of the presence of the sea glider underwater. The shaft of the wind turbine on the surface sled is coupled to an air compressor to produce compressed air that is held within the pressure vessel pontoons of the surface sled.
BACKGROUND
It is well known that air and water are both lifting fluids. Air is merely a more dilute lifting fluid than is water and the principals of science that work in water also work the same in air or; conversely, the scientific principals that work in air work the same in water.
Scientists could not understand how marine mammals traveled for great distances when their food intake which represents their energy input was so low that it would be impossible for them to swim such great distances, when their movements are calculated as a thermodynamic power cycle relating to
energy input and energy output -- as their output of energy appeared to be far greater than their input of energy. They have since learned that the marine mammals use gravity to glide upward and downward through the water.
The mammals after taking in air from the atmosphere at the surface of the water, compress the air to a higher density and a smaller volume within their bodies using their muscles with a simple quick movement that causes them to physically become smaller and heavier than the surrounding water so that they glide downward and forward from the surface. When the mammal desires to rise they can release the force applied by their muscles, causing their physical size to become larger and causing the air within their bodies to expand to a lower density and to a greater volume, which in turn causes the mammal to become lighter-than-water.
The force of buoyancy, the greater pull of the earth’s gravitation field on the water than on the low density air within the
mammal, causes the mammal to rise upward and forward. The forward motion is caused by the resistance of the water to the upward motion, which deflects a portion of the upward motion into a forward motion, known as sea gliding that works exactly the same as an aerodynamic glider works in
air. The energy input of these mammals to provide propulsion through the water is quite minimal -- merely quick muscular movements periodically in order to glide upward and downward through the water as they change from being heavier-than-water to being
lighter-than-water. Thus the mystery of how long range migration of marine mammals is accomplished was solved by discovering their use of gravity’s two forces – buoyancy and gravity acceleration -- in an alternating cycle.
Conventional sea gliders, like their mammal cousins, glide both upward and downward through the water via alternating between buoyancy and gravity acceleration and use almost no battery power to operate as they travel enormous distances. The energy input in order to sea glide is so minute that one small
battery can operate a sea glider for over a year of continuous travel. From a thermodynamic efficiency calculation the sea gliders get far more momentum energy out of the process than is put in as an energy source to provide periodic ballast changes. They harness gravity to provide propulsion.
Sea gliders use a power source, such as an electrical battery, to provide guidance and control of the craft. The amount of power available for the craft is usually extremely minimal and the duration of operation is determined by the amount of stored power that is provided by this power source; however, even with this small power source, sea gliders potentially can operate for more than a year.
Sea gliders harness gravity via mass differentials and this can be proven by their existing operation as opposed to complex mathematical computations. A state-of-the-art conventional thruster powered underwater vehicle can operate for approximately four hours at a velocity of approximately five knots with the best batteries available today that are much larger than those typically used by sea gliders. By comparison a sea glider can operate for up to a year of continuous motion at a velocity of near .5 knot. If the sea glider used its battery power to propel the craft at the same .5
knot velocity like a powered underwater vehicle in level horizontal motion instead of obtaining gravity power by sea gliding, it would only operate for hours or days at best before using up all of its available power. The energy to accomplish the additional range and extended duration of operation is provided by harnessing gravity via mass differentials – alternating from being heavier-than-water to being lighter-than-water in a continuous cycle.
Current sea gliders rise by pumping an oil contained inside the hull into external sacks to increase the volume of the sea glider or use a piston called a “buoyancy pump” located in the nose of the sea glider to discharge water from the hull or inflate a balloon type of gas bag within a flooded section of the tail of the sea glider. Further, it is proposed that sea gliders use a temperature differential to alter the craft from being heavier-than-water to being lighter-than-water, using the ambient temperature of the water, which varies by depth. However, great depth must be accomplished in order to provide sufficient temperature differential for this process to work. And, this is a slow process that provides minimal change in the mass differential of the craft in relationship to the mass of the water, which in turn provides a very slow velocity to the sea glider, as the rate of upward and forward movement via buoyancy or the rate of downward and forward movement via gravity acceleration is a function of the degree of mass differential in mass density between the mass density of the sea glider and the mass density of the water.
Air gliders use very long high aspect ratio wings that are designed with a high degree of aerodynamic capacity in order to obtain very high glide ratios with the most advanced air gliders now obtaining a glide ratio of 100 to 1. The glide ratio extends the duration of flight and the range of the flight, while not affecting the glide speed which is a function of the degree of mass differential alone. An air glider increases its velocity with an increase in weight (increase in the degree of mass differential) with no loss of glide ratio.
Prior art sea gliders unlike their airborne counter-parts do not use high aspect ratio wings to provide greater sea gliding ratios that would further extend their duration of glide and range. In large measure current sea gliders are merely torpedoes with extremely short poorly hydro-dynamically designed wings that provide poor glide ratios.
Further, it is proposed that sea gliders surface and to recharge their batteries using solar energy. However, this strategy has serious drawbacks, because the sun only shines for a portion of the time, it takes substantial time to produce and store solar power via photovoltaic solar cells, and the submersible is subject to detrimental tidal movements and wind forces while remaining on the surface in order to charge its batteries via solar power, etc.
Small sized sea gliders have historically been used for scientific purposes, such as measuring tidal movements, salinity and temperature changes, etc. and have not been used as a mode of transportation or as a mode of cargo transport. They are most often designed for extreme depth and are not designed for shallower depth sea gliding travel to avoid the high hydro-static pressure associated with greater depth.
Hydro-turbines produce power from the flow of water over the turbines’ blades. However, it is well known that power may be produced by the movement of a hydro-turbine through the water instead of the water moving over the hydro-turbine.
Wind powered boats have been constructed that use wind turbines for motive power instead of sails. Power from the wind turbine is transferred to a propulsion device in the water to propel the craft. Unlike sail boats, these craft are able to sail directly into the wind and produce their greatest power and velocity sailing directly into the wind. Existing wind powered boats using conventional horizontal axis wind turbines have achieved velocities exceeding thirty knots.
In pumped storage hydro-electric power plants, a pump powered by an electrical motor pressurizes water to a high elevation. In the reverse mode, pressurized water flows through the pump to cause it to become a hydro-turbine that powers a generator, which is the electrical motor, used in the reverse mode. This process is ninety percent efficient.
A stretched diaphragm has been designed to provide thousands of horsepower for short periods of time to launch torpedoes on submarines. Water is pressurized into one side of the diaphragm that is used as a biasing member, causing it to stretch in the opposite direction. The biasing member applies an equal and opposite force against the water as it stretches. Once the desired pressure has accumulated against the diaphragm, the vessel is sealed. Thus, the energy to launch the
torpedo is stored and held for later use. When it is desired to launch the torpedo, a valve opens, which allows the water pressure to be applied against the torpedo within a cylinder launch tube and the water pressure launches the torpedo with great force. The stretched diaphragm is a method of energy storage.
Another problem with submersibles is occasional catastrophic loss due to insufficient buoyancy. Ships and submersibles occasionally are sunk into the depths of the sea. This happens in part because of the physics of increasing hydrostatic pressure. As a vessel sinks, the air or other gases retained within cavities becomes more and more compressed as the hydro-static pressure increases with depth, which in turn causes the gases to occupy a smaller and smaller volume as they compress. Smaller volume also means less lift capability via the principal of buoyancy, which may be stated as the principal of displacement. As the physical volume decreases due to compression, the area displaced also decreases. Also, pressure vessels containing gases, including the cabins of submersibles, often rupture releasing their gases due to extreme hydro-static pressure applied against the pressure vessels, causing loss of the lift the gases provide.
Once a vessel has lost lift at the surface and begins to sink in water, it is difficult to halt this process; and, as the process of increasing hydro-static pressure progresses, less and less buoyancy is available and the vessel disappears into the depths of the sea, usually ending up on the ocean’s floor and in the case of submersibles often with no survivors.
SUMMARY OF THE INVENTION
The invention herein disclosed is directed more specifically at solving many of the problems of current sea gliders by the innovative use of a hydro-turbine to generate power via the movement of the submersible through water that can generate and store power from the kinetic energy of motion as previously disclosed and the innovative use of a surface sled that can generate power from the motion of a wind turbine through the air and can generate power via solar power from the surface. Additional environmental energy resources that are available to a sea glider, including pressure differentials, temperature differentials, and current differentials, are also disclosed in detail herein. Further, the surface sled may prevent catastrophic loss of an attached submersible if the surface sled has sufficient lift capacity to hold the sea glider in a position so that it does not sink any further.
While the sea glider of the present invention may be constructed as a small research sized unit that is manned or unmanned, it is the intent of this patent application to disclose a sea glider capable of being constructed at a very large size that is capable of carrying cargo and passengers exceeding the capacity of a conventional surface ship. This may be accomplished because of the additional lift capacity of having the entire vessel submerged while a conventional ship only provides lift using the portion of its hull that is submerged for displacement. The apparatus of the present invention also gains the tremendous energy saving benefit of gravity powered sea gliding that is not available to a conventional surface
ship.
The hydro-turbine generates power from the motion of the glider through the water to generate the needed power for operational and ballast control purposes and to produce additional power for other uses. A hydro-turbine will perform in an identical manner either when the hydro-turbine is stationery as water moves over its blades or when the turbine is attached to the sea glider as it moves through stationery water and, likewise, the wind turbine on the surface sled will operate by the motion of the sled through the air. Further, a hydro-turbine and water pump may be used as a thruster to provide propulsion when used in the reverse mode in which pressurized water drives the pump to power the thruster, which is the hydro-turbine used in the reverse mode. Two different processes to provide pressurized water to drive the pump in reverse mode and to provide energy from pressure differentials are disclosed herein: (1) the first being the use of an expanded diaphragm; and, (2) the second is the use of compressed air.
It has been proposed that sea gliders use the temperature differential found within the sea as a power source. This potentially is a slow and marginally effective process. In the present invention, energy may be produced by a hydro-turbine that may be used to heat a high vapor pressure low-boiling-point-liquid to provide a faster and more effective use of a phase change from the liquid to the gaseous phase to provide buoyancy in order to produce lift for a sea glider or conversely the gas may be cooled to reduce lift. The low-boiling-point-liquid may be heated by RF (Radio Frequency) microwaves, may be heated by electrical resistance heating coils, may be heated by thermoelectric modules, or other forms of heat generation derived from stored energy or from energy currently being produced by the hydro-turbine to change to the high pressure gaseous phase.
Further, it has been proposed that sea gliders surface and re-charge their batteries with solar energy. However, the innovative use of a surface sled provides additional methods by which energy may be generated from environmental energy sources. The surface sled allows a wind turbine to generate power from the force of the wind and it also allows solar energy to be gained from the surface via the connecting lines from the surface sled to the submersible.
In the preferred embodiment of the present invention, the sea glider does not have to be sea gliding in order to generate power. The sea glider may be held stationery by an anchor / counterweight that may be lowered to the bottom of the sea. A stationery sea glider may harness environmental energy from: (1) the tidal movement of water over the blades of a hydro-tubine; and, (2) wind energy via the wind turbine at the surface; and, (3)
solar energy via solar cells from the sun at the surface; and, (4) the current differential between the wind and water.
Further, the sea glider does not even have to be anchored to generate power. Power can be generated by the opposing forces of the wind current energy and water current energy. Generally, the tidal current of the water will pull the sea glider underwater in one direction and the wind energy at the surface will pull the sled in a different direction, even if they are merely drifting in these currents, power is produced by the process. Power is obtained via the pressure differential created between current energy applied against the sea glider underwater and wind energy applied against the surface sled in the air that may be harnessed by the wind turbine and/or hydro-turbine respectively.
The innovation of a unique wind turbine that combines both solar energy production and wind energy generation is herein disclosed. Solar cells may be mounted onto the upper surfaces of the blades and support horizontal disk of the wind turbine as well as other structures on the surface sled to produce both solar and wind energy simultaneously.
The surface sled moves along the water’s surface and because it is open to the air it can provide: (1) real-time continuous communication capabilities for the submerged sea glider via a communication line, such as a fiber optic cable, connected to the submersible below water; and, (2) a supply of air to breath while submerged underwater via an air supply line connected to the submersible below water; and, (3) surface visibility via a fiber optic communication line connected to the submersible below water; and (4) radar surface detection and other electronic surface monitoring of the surface via a radar system mounted on the sled using a communication line, such as a fiber optic cable, connected to the submersible below water; and, (5) a stored air supply from the surface to use for ballast control on the submersible via an air supply line connected to the submersible below water that will allow the
submersible to use air to blow ballast water out of the glider in order to gain buoyancy without having to rise to the surface to acquire air. The sled can hold a pressure vessel having a pressurized air supply without negatively affecting the buoyancy of the submersible because the pressure vessel filled with compressed air is not on the submersible itself but rather is on the surface on the sled. The tank can remain filled by a wind turbine driven air compressor that uses the kinetic energy of the motion of the wind turbine through the air and via the kinetic energy of the wind blowing along the water’s surface as an additional energy source; and, (6) notification of the presence of the submersible below water via the visible surface sled, like a diver’s flag floating on the surface, and via air bubbles that will continuously rise from the submersible, like a divers bubble trail. Emergency signals may be placed on the sled in order to provide notification at the surface that there is a problem with the submersible below and the submersible can be reeled to the surface via the connecting lines if necessary; and (7) ability to acquire GPS global satellite positioning while submerged all of the time to more accurately navigate the sea glider; and, (8) supply electrical power when the sun is shining that is produced via solar cells mounted on the sled and mounted on the horizontal disc and shutters of the wind turbine; and, (9) emergency location of the sea glider via the surface sled located at the surface with the sea glider attached below; and, (10) provides a means via return air lines from the sea glider to the surface sled to discharge spent air back to the lower pressure atmosphere, which requires less pressure than discharging air into the water which must be at a higher pressure than the hydrostatic pressure of the water in order to enter the water; and, (11) added safety from catastrophic loss of the sea glider as the surface sled will provide buoyancy for the sea glider to prevent it from going to the bottom of a deep ocean in the case of ballast system failure of the sea glider that makes it impossible for the sea glider to return to the surface on its own and will supply needed air to the sea glider until a rescue can be accomplished by pulling the sea glider up from the depths by its line connected to the surface sled.
Environmental energy and gravity power energy sources available to the sea glider are: (1) wind power from both wind energy from the environment; and, (2) wind energy from the motion of the wind turbine through the wind as the sled is pulled forward by the submersible; and, (3) hydro-power from the kinetic energy of motion of the submersible the surface sled through the water if it has a hydro-tubine attached that is under the surface of the water; and (4) hydro-power from the kinetic energy of motion of the submersible through the water with hydro-turbines attached to the sea glider; and, (5) hydro-power produced by the motion of water over the hydro-tubines while the sea glider and surface sled are stationery; and (6) power produced as a result of temperature differentials that occur due to changing depths within the water or as a result of height within the air in regards to an
airship; and, (7) solar energy from solar cells mounted on the surface sled and wind turbine that remain at the surface all the time; and, (8) power generated from pressure differentials; and, (9) power generated from current differentials, using air currents at the surface acting upon the surface sled and water currents underwater acting upon the sea glider.
The sea glider of the present invention uses very long high aspect ratio wings that are designed with a high degree of aerodynamic capacity in order to obtain very high glide ratios of perhaps as high as 100 to 1. The glide ratio extends the duration of flight and the range of the flight, while not affecting the glide speed which is a function of the degree of mass differential alone. The glide ratio of the sea glider is very important because as the glide ratio increases more power is generated between ballast changes and a greater distance is traveled between ballast changes, which conserves valuable energy resources.
An improved glide ratio also means that a shallower glide path may be followed. This is important if the purpose of the vessel is to transport
passengers and cargo and it is desirable for the craft to be designed for shallower depth travel to avoid the high hydro-static pressure associated with greater depth.
The sea glider of the present invention will increase its velocity with an increase in the degree of mass differential with no loss of glide ratio and will attempt to produce as much mass differential at each ballast change as is reasonably practical.
Heavy lifting capability in excess of a surface ship may be achieved because the sea glider is fully buoyant as it fully sinks below the surface as where a surface ship only creates buoyancy using that portion of its hull that is below the surface of the water to create lift.
A sea glider may be constructed with a portion of its hull being pliable. This would allow the sea glider to become smaller and heavier than water when flooded with water and would then allow the pliable portion of the hull to be expanded via air pressure to make it buoyant in water. A flexible collapsible gas bag may be inflated to produce additional buoyancy.
A sea glider may be constructed with a hydraulic ram within lifting body pontoons that allow the cylinder of the ram to be flooded with water to lose buoyancy or filled with compressed air that forces the water out of the cylinder via the air being injected on the opposite side of the piston than the side containing the water that is discharged from the sea glider to gain buoyancy. Thrust is achieved by the rapid discharge of water from the lifting body pontoons.
In the alternative a ram may be operated by the use of hydraulic power to withdraw the piston in order to form a vacuum on the opposite side of the piston. In the preferred embodiment of the invention, both of these methods are used simultaneously. As hydraulic force provided by the hydro-tubine forces the piston backward, compressed air is supplied to the opposite side of the piston to reduce the energy (negative force of the vacuum) required to withdraw the piston by the hydraulic force. This is especially beneficial when substantial depth is encountered as the pressure of compressed air alone may not be sufficient to push the piston back due to the hydrostatic pressure of the water surrounding the sea glider. However, the pressure supplied by the compressed air makes it easier for the hydraulic force to move the piston backward to expel the ballast water from the sea glider. Further, the hydraulic ram acts as a backup to the failure of the supply of compressed air due for any reason. The ram may be operated by battery power or by the use of the hydro-turbine as an additional backup.
The preferred embodiment of the invention accomplishes dramatic ballast change with substantial mass differential by rapidly blowing water ballast out of lifting body pontoons located on the glider using compressed air provided from the surface sled via a connecting high pressure air line. The rapid ballast change accomplishes a powerful buoyant lifting force via the principal of buoyancy that is translated into forward and upward glide velocity. Thus the sea glider of the present invention is capable of gliding at substantial speeds that are far greater than the velocity attained by prior art sea gliders.
Thrust may be attained as the ballast is being blown from the ballast tanks by high pressure air by providing a jet propulsion nozzle that the water rapidly flows through to create an equal and opposite reaction via Newton’s Third Law.
Upon reaching a desired depth while ascending upward via the powerful lift force describe above, the compressed air is rapidly released from the lifting body pontoons by the opening of upper and lower hatches and the pontoons are again flooded with water. After the pontoons have been flooded, the hatches again close.
The degree of mass differential determines the amount of power available to a sea glider in water or gravityplane in air. The degree of mass differential is a function of both the quality and quantity of mass differential. The quality refers to the degree of mass differential between the lifting fluid and object lifted within the fluid. The quality of lift of air in water is 821 times greater than the quality of lift of a vacuum in air or almost a thousand times the quality of the lift of helium in air. The quantity refers to how much physical volume of lift is obtained by cubic area. To produce a large amount of power even if the quality of mass differential is good as it is for the sea glider, the quantity or number of cubic feet of displacement must still be significantly large as well.
Further, in order to have a stable velocity for fuel-less flight gravity powered gliding in air or for sea gliding in water the two forces of gravity must be in almost perfect balance. The amount of mass differential of gravity acceleration must match the amount of mass differential of buoyancy. For example if a sea glider has a net weight when in the heavier-than-water mode of 620 pounds to provide a downward motive gliding force, then it must have a net lift of 620 pounds in the lighter-than-water mode in order to obtain the same velocity in gliding upward. The ballast change of buoyancy accomplished then must be 1,240, with the first 620 pounds equaling and canceling the net weight of the heavier-than-water mode and then an additional 620 pounds of lift to provide a net lift via buoyancy of 620 pounds in the lighter-than-water mode.
The velocity will decrease as the mass differential decreases. In the preferred embodiment of the present invention, thrusters using stored energy are used to transition between the heavier-than-water modes of operation to the lighter-than-water mode to maintain a constant velocity. The hydro-turbine becomes a thruster in the reverse mode operation to provide propulsion power. The hydro-turbine that is powered by water movement is connected via a shaft to a hydraulic pump that provides a flow of high pressure water that is used for ballast change and for other uses in normal power generating use. In the reverse mode high pressure water is forced through the pump and the pump becomes a hydro-turbine itself to provide power to the thruster.
An innovative counter-weight is used to make the sea glider substantially heavier than the surrounding water when the pontoons are flooded. The counterweight provides forceful gravity acceleration for the sea glider to maintain the velocity in the downward and forward directions via the principal of gravity acceleration and gliding. The pontoons are flooded with water and the glider sinks lower in the water as the cables wench the craft underwater. Once the anchor is attached to the underside of the craft, sufficient water is displaced from the pontoons by compressed air to cause the craft to rise upward via buoyancy and to also begin an upward and forward glide through the water. Near the surface the air is discharged and the sea glider begins to move downward as it maintains its forward momentum.
Conventional submarines must surface to get a new supply of air after blowing ballast to gain buoyancy to rise to the surface.
Like a diver’s flag floating at the surface while the diver is underwater, the sled moving through the water will provide surface notification that the submersible is forward of and below the direction of movement of the attached sled that is being towed along the surface of the water.
Also, the air used for breathing in a manned sea glider will be exhausted back to the surface via the return air line to the surface sled to maintain good quality and to prevent unwanted floatation. Also, less energy is beneficially required to exhaust the air to the surface as the surface has less pressure than the hydro-static pressure at depth.
The glider may also be used as a boat using stored power, i.e. electrical power storage such as batteries or compressed air may be used as a power storage medium, etc.
The preferred embodiment of the sea glider is made of lightweight strong composite materials, instead of metal materials as is used by most submersibles. The counter-weight is removed and the pontoons are filled with air on the water’s surface and the craft becomes a boat and floats high in the water like a conventional boat. And, thus, may be used as a boat to travel along the surface of the water. Energy produced and stored during sea gliding may be used to power the boat via stored electrical energy or stored compressed air to run pneumatic motors to provide mechanical drive, etc.
The sea glider invention herein disclosed innovatively uses three different apparatus to create a new improved sea glider; (1) the composite sea glider that is the main vessel that may be lighter than a conventional submersible and may be used as a boat; and, (2) the sled that may be used to provide the above mentioned advantages; and, (3) a counter-weight device that may be connected to the main sea glider vessel or may be used as an anchor to hold the position of the sea glider and sled stationery. Further, a valuable cargo may be used instead of a counterweight in order to be transported by the sea glider, making the sea glider a cargo transport vessel.
The counterweight provides an additional safety feature for the sea glider as the craft is made of materials that are lighter-than-water and only sinks because of the weight provided by the counterweight. The counterweight may be disconnected from the submersible in order to allow it to surface in the event of failure of the crafts dual ballast system – compressed air supply and hydraulically and/or electrically powered ram to create a vacuum. In the event of release of the counterweight, the submersible is capable of making a rapid emergency ascent.
As a cargo carrying vessel, the counterweight may consist of cargo that is being transported by the sea glider. The innovative use of a modular cargo counterweight system disclosed herein allows the cargo to be transported in individual sections once the location of delivery of the cargo has been attained. It requires all or most of the cargo counterweight to make the sea glider heavier-than-water; therefore, a portion of the weight of the cargo counterweight can be transported on the surface by the sea glider, perhaps as much as one-half of the cargo weight, which would allow the cargo to be delivered in two trips to the port or the other half to be lifted onto a second vessel. Additional cargo or a counterweight must be obtained in order for the sea glider to again submerge. This could be accomplished by beneficially backhauling a second cargo.
A supply line reel housed on the surface sled controls the length of the line from the surface sled to the sea glider. The line may be wound around the Reel to bring the surface sled and sea glider fully together. Once together, the sea glider mounts underneath the surface sled to form one surface vessel having the combined capabilities of the surface sled and the sea glider.
The surface sled contains communications equipment such as radar and long distance visual aides, wind power and solar power, stored energy via its high pressure compressed air tanks and electrical energy storage batteries. The sea glider has hydro-turbines that remain below the surface to produce power from tidal movement of from the kinetic energy of movement through the water is the combined craft is being propelled by the wind turbines, solar power, or stored electrical power, the sea glider also has stored electrical energy stored in batteries.
The pontoons of the surface sled are pressure vessels that store high pressure compressed air that filled when wind energy is available either from environmental wind energy or from wind power created by the forward movement of the surface sled through the wind when the sea glider is providing power to pull the surface sled forward via sea gliding energy.
The anchor may be removed at such time that it is desirable to use the surface sled and sea glider when connected together as a surface vehicle. The anchor acts as a counterweight to hold the sea glider underwater. Without the counterweight anchor, the sea glider will float high up on the surface of the water like a conventional surface vessel. The anchor counterweight may be re-attached when it is desirable to resume sea gliding underwater or it may be simply allowed to rest on the bottom underwater to act as an anchor, which also removes the weight associated with the anchor counterweight from the sea glider so that it will float high on the surface of the water. In the alternative, the anchor counterweight may be lowered to the bottom to hold the sea glider in a stationery position below the surface of the water.
The vertical axis hydro-turbine invented by the present applicant has far less drag than that of a conventional hydro-turbine as one side is in the position of a horizontal disk having low drag through the water and the other side of the vertical shaft has shutters open to ninety degrees perpendicular to the oncoming water as the sea glider moves through the water and the shutters move backward as the force of the water acts upon the shutter to further reduce drag. In comparison a conventional hydro-turbine produces drag across its entire swept area, which is the area within the entire circumference of the hydro-turbine’s blades, like that of a vertical propeller that is on a horizontal axis.
A sled moves along the water’s surface and because it is open to the air it can provide: (1) real-time continuous communication capabilities for the submerged sea glider via a communication line, such as a fiber optic cable, connected to the submersible below water; and, (2) a supply of air to breath while submerged underwater via an air supply line connected to the submersible below water; and, (3) surface visibility via a fiber optic communication line connected to the submersible below water; and (4) radar surface detection and other electronic surface monitoring of the surface via a radar system mounted on the sled using a communication line, such as a fiber optic cable, connected to the submersible below water; and, (5) an air supply from the surface to use for ballast control on the submersible via an air supply line connected to the submersible below water that will allow the submersible to use air to blow ballast water out of the glider in order to gain buoyancy without having to rise to the surface to acquire air. The sled can hold a pressure vessel having a pressurized air supply without negatively affecting the buoyancy of the submersible because the pressure vessel filled with compressed air is not on the submersible itself but rather is on the surface on the sled. The tank can remain filled by a wind turbine driven air compressor that uses the kinetic energy of the motion of the wind turbine through the air and via the kinetic energy of the wind blowing along the water’s surface as an additional energy source; and, (6) notification of the presence of the submersible below water via the visible surface sled. Emergency signals may be placed on the sled in order to provide notification at the surface that there is a problem with the submersible below and the submersible can be reeled to the surface via the connecting lines if necessary; and (7) ability to acquire GPS global satellite positioning while submerged all of the time to more accurately navigate the sea glider.
Energy sources available to the sea glider are: (1) wind power from both existing wind energy from the environment; and, (2) wind energy from the motion of the wind turbine through the wind as the sled is pulled forward by the submersible; and, (3) solar power via solar cells on the wind turbine and surface of the sled; and, (4) hydro-power from the kinetic energy of motion of the submersible through the water; and, (5) power produced as a result of temperature differentials that occur due to changing depths within the water or as a result of height within the air in regards to an airship; and, (6) power produced as a result of pressure differentials.
Heavy lifting capability in excess of a surface ship may be achieved because the sea glider is fully buoyant as it fully sinks below the surface as where a surface ship on creates buoyancy using that portion of its hull that is below the surface of the water to create lift.
The preferred embodiment of the invention accomplishes dramatic ballast change with substantial mass differential by rapidly blowing water ballast out of lifting body pontoons located on the glider using compressed air provided from the surface sled via a connecting high pressure air line. The rapid ballast change accomplishes a powerful buoyant lifting force via the principal of buoyancy that is translated into forward and upward glide velocity. Thus the sea glider of the present invention is capable of gliding at substantial speeds that are far greater than the velocity attained by prior art sea gliders.
Upon reaching a desired depth while ascending upward via the powerful lift force describe above, the compressed air is rapidly released from the lifting body pontoons by the opening of upper and lower hatches and the pontoons are again flooded with water. After the pontoons have been flooded, the hatches again close.
The innovative use of a counter-weight is used to make the sea glider substantially heavier than the surrounding water when the pontoons are flooded and a forceful gravity is gained by the sea glider to maintain the velocity in the downward and forward directions via the principal of gravity acceleration.
The preferred embodiment of the sea glider is made of lightweight strong composite materials, instead of metal materials as is used by most submersibles. When the pontoons are filled with air on the water’s surface, the craft becomes a boat and float high in the water like a conventional boat and thus may be used as a boat to travel along the surface of the water. Energy produced and stored during sea gliding may be used to power the boat via stored electrical energy or stored compressed air to run pneumatic motors to provide mechanical drive, etc.
The sea glider is innovatively coupled to a surface sled that remains on the surface of the water to produce energy from wind via a wind turbine and solar energy via solar cells as the sea glider moves underwater. The sea glider and surface sled are connected via a tube that contains a bundle of individual lines for; radar, GPS, and visual communications, to supply compressed air from the surface sled to the submersible for ballast control and for breathing by occupants, to allow spent air to return to the surface to a lower pressure, to provide warning notification at the surface of the presence of the sea glider underwater. The shaft of the wind turbine on the surface sled is coupled to an air compressor to produce compressed air that is held within the pressure vessel pontoons of the surface sled.
The sea glider invention herein disclosed innovatively uses three different apparatus to create a new improved sea glider; (1) the composite sea glider that is the main vessel; and, (2) the sled that may be used to provide the above mentioned advantages; and, (3) a counter-weight device that may be connected to the main sea glider vessel or may be used as an anchor to hold the position of the sea glider and sled stationery.
An upward lifting force is generated by the force of buoyancy and a downward sinking force is generated by the force of gravity acceleration. The present invention is capable of generating energy via harnessing the upward motion caused by the force of buoyancy and the downward motion caused by the force of gravity in an alternating back-and-forth cycle more fully described herein.
In order to create a power cycle using buoyancy for lift and gravity acceleration as a downward motive force, there must be the ability to change the overall density of the body of mass that is being lifted within a surrounding lifting fluid via buoyancy to a higher density that will sink within the surrounding lifting fluid. For example, an enclosure containing a low density gas or having a vacuum may rise within a column of liquid and an enclosure containing a low density gas or a vacuum may rise within a column of heavier gas via buoyancy. To change the density of the enclosure containing a low density gas or a vacuum to a heavier configuration, the gas may be compressed or the vacuum may be released and than a heavier gas or liquid may be allowed to enter the enclosure taking the area previously occupied by the low density gas or vacuum, making the entire enclosure heavier than the lifting fluid so that it is capable of sinking via the greater gravitational pull of the earth on the heavier enclosure.
A greater mass differential means more forceful glide and faster velocity.
A phase change power cycle is thus created by alternately creating buoyancy via vaporizing a liquid to a low density gas that is lighter-than-air within an enclosure to create lift by changing the working fluid within the enclosure from the liquid state or solid state to the gaseous state. Then the lift is lost by altering the density of the enclosure by causing a phase change of the gaseous state working fluid to the liquid or solid state. Lift is lost because the density per cubic feet of the gas is greatly increased as a result of the phase change and the area previously occupied by low density gas is filled with high density liquid, which causes the mass of the enclosure to be much greater so that its density is greater than the density of the lifting fluid and it sinks via gravity acceleration. To continue the cycle, lift must be re-established when the enclosure has reached a lower elevation which may be accomplished by vaporizing the liquid back to the gaseous state in an alternating cycle.
A novel gravity powered fuelless sea glider is herein disclosed using a phase change technique to alter the sea glider’s density to being greater than the surrounding water by causing a working fluid to change phase to the liquid phase to create gravity powered gliding flight and then alternately at a greater depth the process is reversed to re-establish buoyancy lift by changing the working fluid back to the gaseous state in an alternating cycle.
Compressed air produced by the surface sled may assist the phase change process. When air is compressed, substantial heat is produced via the heat of compression. The heat may be used to vaporize a low-boiling-point-liquid via a heat exchanger.
Compressed air can also be used to accomplish liquefication of the vapor by removing the heat of compression by heat rejection to the environment then expanding the air to provide source of cooling to condense the vapor to the liquid phase. Expansion of the air will cause its temperature to dramatically drop to an extremely cold temperature to refrigerate the vapor to cause the gas within to change to the liquid state and a subsequent reduction in the volume of the working fluid will occur.
A second process for the liquefication of the gas is to compresses the gas, remove the heat of compression via heat exchange with the surrounding to reject heat and then expand the gas through a Joules-Thompson valve or a work producing turbo-expander, causing a large portion of the gas to liquefy.
The amount of power generated may be measured as the degree of mass differential with greater power output being generated as the mass differential increases. The greater the degree of mass differential; the greater the gravity powered energy output. Time must also be taken into consideration as an energy output factor. A given amount of energy input must be used to alter the mass from the gaseous state to the liquid state or from the liquid state to the gaseous state to make an enclosure lighter than the surrounding fluid or heavier than the surrounding fluid. The distance or height between phase changes that occur within the apparatus to change its ballast determines the period of useful time that elapses before another phase change must occur in the alternating phase change cycle. The greater the height or distance between phase changes in the upward and downward vertical plane; the greater the energy output. Height directly relates to potential energy. The greater the depth that the sea glider achieves in the heavier-than-the-surrounding-fluid mode, the more kinetic energy it achieves while rising after the mass of the enclosure has been altered to the lighter-than-the-surrounding-fluid mode via a phase change to the gaseous state. The height between phase changes of the apparatus determines the amount of potential energy gained in the lift process via buoyancy.
The heat of compression of air from the surface may be used to heat to the cabin area of a manned sea glider. The temperature of the air is dramatically increased via the heat of compression. The heat may be removed by heat exchange in the cabin, then the compressed air with its heat removed can be beneficially used on the gravityplane to provide on-board power then discharged as not to add weight to the sea glider to affect ballast control if desired or it may be used to create further buoyancy. Thus, air from the surface aides in temperature control of a manned sea glider.
LINKS
www.eng.uah.edu/~fahimi/Platform_Boat.html
www.gps4us.com/GPS-navigation-autonomous-vessels
http://en.wikipedia.org/wiki/Geodetic_system
http://en.wikipedia.org/wiki/ECEF
www.apl.washington.edu/projects/seaglider/summary
www.seaglider.washington.edu/
http://en.wikipedia.org/wiki/IRobot_Seaglider
TropicalBoats
http://www.imos.org.au/
http://www.uberreview.com/2008/02/
htmhttp://rucool.marine.rutgers.edu/deepwater/
http://www.webbresearch.com/slocumglider.aspx
Solarnavigator
is a battery electric ASV (Autonomous Solar Vessel), a trimaran with an extremely
efficient
active hull that runs on solar
power = energy from nature. This hull form has never been
attempted
before, nor has the use of wind energy been used in such manner for crew
comfort
(or
complete onboard autonomy). A fleet of such vessels could be the basis of an
international peacekeeping, and/or emergency rescue force.
Project
Objectives
AUTONOMY
| STEALTH
Galley
| Paints | Screens | Diving
Project
Estimates | Record Attempt | PR Events
Batteries
| Alloys | Timber | Composites | Navigation | Hydraulics
Motors
| Electronics | Solar
Panels | Propeller | Transmission | Tooling | Life Support
Tank
Testing (Model
Construction) & Results
 
The
design of the Solar Navigator boat
has been licensed for use in
the
John Storm series of books by
Jameson Hunter
|