Patent Application
20090314269
1. Field of the Invention
The invention relates in general to a device that accelerates an object or a fluid, and in particular to a device that accelerates an object to high velocity by a helical force field that converts rotational kinetic energy in the device into linear kinetic energy in the object or fluid, and alternatively, that decelerates an object or a fluid from high velocity to low velocity by converting the linear kinetic energy into rotational kinetic energy.
2. Description of the Related Art
There are many different types of accelerating devices. For example, a railgun is a device in which electrical current is made to flow cross-wise through a conductive projectile, causing the projectile to become magnetized. Because magnetic fields and electrical current are repelled by each other, and because this repulsive force always acts in a direction perpendicular to the flow of the electrical current, the projectile is made to accelerate forward in response to this current flow.
Because railguns are powered by electricity, they require heavy and complex systems to store this electrical energy, and to produce and condition their huge electrical power pulses. For example, the University of Texas Center for Electromagnetics is creating an experimental rail gun for the US Marines that will accelerate a 2 kg projectile to 2.5 km/s. The railgun requires a power system that produces a 30 GigaWatt electrical pulse, stores hundreds of megajoules of energy, and weighs many tens of tons.
Railguns operate at extreme current densities. As a comparison, a resistance welder, which uses electrical current to melt and weld material, operates at a fraction of the current density of typical high energy railgun. The high current density required by railguns causes extreme wear on the rail and barrel, and as a result, practical railguns can achieve projectile velocities of no more than about 2.5 km/s. Railguns that do reach greater velocities are typically single-shot, or nearly single-shot.
In a railgun, the accelerating magnetic field is produced by what is essentially a single-turn coil. Generating the required high magnetic-flux density using such a coil requires an extremely high current density, combined with a relatively low voltage. However, concerns over the maximum current carrying capacity of the conductors typically limit a railgun's magnetic flux density to approximately 5 Tesla, which in turn limits a railgun's accelerating force.
Railguns use an arc of plasma to make the electrical contact between the projectile and the rails. Therefore, it is essential that this plasma arc accelerates at the same rate as the projectile. However, with existing railgun technology, it is not possible to control the plasma arc in a repeatable manner when operating at very high velocities and power densities. As a result, the plasma arc typically either lags behind the projectile, or passes it, further limiting the efficiency and maximum velocity that a railgun can attain.
In a coilgun, also known as a “mass driver”, or “co-axial accelerator”, a projectile is made to pass through a series of electromagnetic coils, or solenoids. These solenoids are precisely controlled to turn on, or become magnetic, as the projectile is approaching, and to turn off the instant the projectile passes, allowing the projectile to be pulled forward by the next solenoid in the series.
The magnetic pressure that is applied to an object by a solenoid decreases with the square of the distance between the object and the solenoid's center. Therefore, to get the maximum efficiency out of a coilgun, the projectile must be allowed to approach as closely as possible to the center of each soil (solenoid) before the coil is turned off. However, if the projectile is allowed to pass through the center of the coil before the coil is completely turned off, the magnetic force that was previously accelerating the projectile will now be pulling it back, causing the projectile to slightly decelerate. As the ultimate velocity of the projectile increases, the turn-off time of each coil must decrease for the efficiency of the accelerator to be maintained. However, it is a fundamental characteristic of magnetic coils to create self-generated magnetic fields, which act to keep the coils partially energized (and thus partially magnetized) even when there is no current flowing to them. This characteristic of magnetic coils makes it very difficult to turn them off quickly enough. As a result, the efficiency of the coilgun decreases rapidly with increasing projectile velocity, and coilguns that operate at practical energy density levels are even more limited in their velocity than railguns.
In a conventional (explosive) gun, expanding gas from a chemical explosion pressurized the inside of a barrel behind the projectile. Because the projectile forms a sliding seal between itself and the barrel, it is accelerated by the pressurized gas behind it.
Due to gas dynamics limitations, a chemical-explosive gun cannot accelerate a projectile to a velocity that exceeds the blastwave velocity of the explosive being used. The highest blastwave velocity attainable with a chemical explosive is 2 km/sec. Therefore, even if provided with an infinitely long barrel, a conventional gun cannot accelerate a projectile beyond 2 km/s. Furthermore, the tremendous amounts of ammunition that would be required to operate a conventional gun for extended periods at high rates of fire would make it highly impractical for applications involving continuous operation, such as cutting or drilling.
A light gas gun uses a chemical explosive to produce the energy used to accelerate the projectile. However, a light gas gun circumvents the blastwave velocity limitations of a conventional gun by using its explosive to first accelerate a specific volume of low density gas, or “light gas”, such as hydrogen, which is held in a series of stages behind the projectile. Upon discharge, a sliding piston, driven by the expanding gas from the conventional explosion, compresses the lower density gas in front of it, creating a second blastwave. However, unlike the relatively massive byproducts that make up the conventional explosive's blastwave, the lower mass of the “light” gas allows it to be driven to a much higher velocity by the same amount of energy. As a result, projectiles fired from light gas guns can reach velocities of 8 km/s or more.
Each shot of a light gas gun requires extensive manual preparation. For example, they typically use an exploding metal valve between each stage, which must be replaced after each shot, making continuous firing impractical. Furthermore, because barrel length and piston mass increase rapidly with projectile mass and velocity, light gas guns do not scale well to larger sizes. This characteristic limits the use of light gas guns to highly specialized research applications, within controlled laboratory environments.
The inventor of the present invention has recognized these and other problems associated with conventional accelerating devices, and has developed a cost-effective and energy efficient device for accelerating (and decelerating) an object are extremely high speeds.
In one embodiment of the invention, a helical field accelerator comprises one or more rotating members having outer surfaces in close proximity of each other; and a conduit disposed on the outer surface of one of the rotating members in the form of a helix, the conduit having a fluid disposed therein, wherein the conduit is influenced by the other one of the rotating members to transmit rotational kinetic energy of the one or more rotating members to a projectile disposed within the conduit, thereby converting rotational kinetic energy of the rotating members to linear kinetic energy of the projectile.
In another embodiment of the invention, a device comprises a first magnetic structure in close proximity to a second magnetic structure that produces a localized magnetic field having a variable pitch, wherein rotational kinetic energy of the magnetic structures is converted into linear kinetic energy in an object.
In yet another embodiment of the invention, an accelerator for accelerating an object comprises a plurality of structures, one of said plurality of structures comprising at least one rotating structure that interacts with another one of said plurality of structures to produce a helical field upon an object to cause the object to accelerate along said plurality of structures.
In the drawings:
a shows a plan view of the structure of
b shows a plan view of the structure of
a and 16b show a cross-sectional view of an alternative embodiment of a rigid conduit according to the invention in an open, unsealed position and a closed, sealed position.
a and 17b show a side view and a front view, respectively, of a magnetic-pressure accelerator having two rotating helical magnetic structures or cylinders according to an embodiment of the invention.
a and 18b show a side view and a front view, respectively, of a magnetic-pressure accelerator having one rotating helical magnetic structure and one linear magnetic structure according to an alternate embodiment of the invention.
a and 19b show a side view and a front view, respectively, of a magnetic-pressure accelerator having one rotating helical magnetic structure and two linear magnetic structures according to an another alternate embodiment of the invention.
a and 20b show a side view and a front view, respectively, of a magnetic-pressure accelerator having one rotating helical magnetic structure and three linear magnetic structures according to yet another alternate embodiment of the invention.
a and 21b show a side view and a front view, respectively, of a magnetic-pressure accelerator having two rotating helical magnetic structures and one linear magnetic structure according to still yet another alternate embodiment of the invention.
a and 22b show a side view and a front view, respectively, of a magnetic-pressure accelerator having one rotating helical magnetic structure and a rotating linear magnetic structure according to still yet another alternate embodiment of the invention.
a and 23b show a side view and a front view, respectively, of a magnetic-pressure accelerator having two concentric rotating helical magnetic structures according to still yet another alternate embodiment of the invention.
a and 24b show a side view and an end view, respectively, of a magnetic-pressure accelerator having two concentric rotating helical magnetic structures surrounded by a magnetic field according to yet another alternate embodiment of the invention.
a and 25b show a side view and an end view, respectively, of a magnetic-pressure accelerator having two concentric rotating helical magnetic structures surrounded by a magnetic field according to still yet another alternate embodiment of the invention.
The principles of the invention will now be described. In general, a helically configured structure 1, or an array of structures capable of producing a localized pressure field is arranged in a helical, or spiral, pattern, is shown in
Referring now to
When the helically configured structure or structures 2 are made to rotate relative to each other (indicated by the arrows in
The pressure waves travel down the structures 2, 3 at a rate that is related to the pitch of the helix at any particular point. In a region of the helix where the pitch is lower than 1:1, or less than 45°, the speed of the traveling pressure wave will be some fraction of the rotational surface-speed of that point on the helix. In a region of the helix where the pitch is higher that 1:1, or greater than 45°, the speed of the traveling wave will be some multiple of the rotational surface-speed of that point on the helix. Thus, assuming a constant speed of rotation, in a region of low helix pitch, the pressure wave moves slowly; in a region of high pitch, the pressure wave travels more rapidly.
Because the pitch of the helix varies from relatively low at its beginning, to relatively high at its end, the resulting pressure waves travel relatively slowly at the beginning of the helix and progress down it at an ever increasing rate. When the final pitch ratio of the helix is very high, for example 50:1, extremely high pressure-wave velocities can be produced using relatively moderate rotational speeds.
When a pressure-responsive object is placed in or near one of these traveling pressure waves 5, the object will be accelerated, or decelerated, depending on whether the pressure wave is traveling in the direction of increasing pitch, or decreasing pitch, along the helix.
In the case where the device is being used as an accelerator, this variation in the speed of the pressure waves allow the device to accelerate an object gradually, ensuring that the force holding it within the pressure wave is not exceeded. Furthermore, by matching the helix pitch and helix rotation speed to the mass of the object, the pressure wave can be made to accelerate the object at the highest rate that object's inertia will allow. This direct control that the device allows over the velocity of the pressure wave makes it possible to precisely match the acceleration rate of the pressure wave to the maximum possible acceleration rate of the object, ensuring that the pressure wave does not leave the object behind.
The above acceleration mechanism can employ a variety of pressure fields, including contact and non-contact fields. Examples of contact pressure fields include fluid pressure against a surface, and the pressure created by the direct mechanical contact between one surface and another. Examples of non-contact pressure fields include magnetic fields, and electrostatic fields. For the sake of convenience, however, the following device configurations will all contact pressure fields to be from fluid pressure, and all non-contact pressure fields to be from magnetic pressure. Among those configurations that employ fluid pressure, a distinction will be made between compressible and non-compressible fluids.
A Fluid-Pressure Accelerator
In general, in a helical accelerator that employs fluid pressure, the rotational kinetic energy in the device is transmitted to the projectile through the medium of a fluid, such as water, or the like, which acts as a buffer between the rotating members of the device and the projectile. This buffer fluid may be either a compressible or non-compressible fluid.
Referring now to
Referring to
The cylinders 11, 12 are driven rotationally in the direction of advancing helix pitch with the starting point of the helix being the end with the lowest pitch, and the final point of the helix being the end with the highest pitch. During rotation, the intersection of these two cylinders 11, 12 with the conduit 10 creates a traveling pinch-point (indicated by the ‘X’), which moves down the cylinders 11, 12 in the direction of increasing helical pitch.
When a controlled volume of fluid is introduced into the conduit 10 at the point of lowest pitch, this volume will be captured by and pushed ahead of this traveling pinch-point, thereby forcing the captured fluid to travel through the conduit at the same rate as this intersection point. Because the conduit 10 is arranged around the cylinder 11 in a helix of increasing pitch, the rate at which the pinch-point travels down the cylinder 11 increases accordingly, even though the rotation speed of the cylinders 11, 12 may be constant.
Referring now to
The fluid may either be drawn into the conduit 10 under its own pumping action, or the fluid may be forcibly injected. In the case where a compressible fluid, or gas, is used, it may be desirable to introduce the gas into the conduit with an initial pressure, in a pre-compressed state. By pre-compressing the gas in this way, the accelerator is able to devote more of its length to the actual acceleration of the gas, rather than having to first compress it before bringing to bear the full accelerating force. This pre-compression may be accomplished either through the use of a separate pumping stage, or through a chemical reaction during injection, such as a chemical explosion.
In the case where a non-compressible fluid is used as the buffer fluid, it may be desirable to introduce the fluid into the conduit 10 with an initial velocity. Because the helical conduit would not have to accelerate the fluid from a standing start, this would allow a higher cylinder rotation speed and a correspondingly higher fluid exit velocity.
It should be noted that the friction between the fluid and the wall of the conduit 10 is proportional to surface area. It is therefore desirable to limit the volume of the buffer fluid in each uptake to only the amount needed to perform the work required by a particular application. As shown in
The resulting pulsed characteristic of its operation distinguishes the device 100 from a conventional pump, where the intent is typically to produce continuous flow. As a result of its pulsed operation, the helical accelerator 100 is not subject to cavitation, in which a fluid is forced to separate into both its liquid and gas states. In a conventional continuous-flow pump, fluid is both drawn or “pulled” into the pump on the intake side, and expelled or “pushed” through the output side. It is during the intake stage that cavitation can occur, where the dramatic acceleration of the fluid subjects it to such low pressure that it partially vaporizes. Due to the resulting gas in the fluid stream, the pump now must act on a fluid which is elastic in nature. This elasticity limits the force that can be exerted on the fluid during the time it is within the pump, and therefore limits the acceleration that the fluid can undergo. In contrast, in the helical accelerator 100 of the invention, the primary acceleration of the fluid occurs while the fluid is under compression on the “push” side of the pump, which therefore makes cavitation impossible. This allows the device 100 to exert an extremely high accelerating force on the fluid.
One aspect of the device 100 is that no sliding contact occurs between the cylinders 11, 12 and the conduit 10 during compression. As a result, wear on the conduit 10 is minimized.
In one embodiment of the invention shown in
Referring to
As shown in
As shown in
In an alternate configuration of a device 100′ is shown in
Alternatively, this same effect may be achieved by the use of a series of pistons or rams 32 arranged linearly along the conduit 33, which are actuated in a controlled sequence to produce the effect of a virtual helix, as shown in
When a fluid pressure accelerator is used to directly accelerate an object traveling within the conduit, a rigid, non-elastomer conduit may be preferable, due to its ability to guide and stabilize the projectile within its walls.
One such method of implementing a rigid conduit 102 with a reducible cross section is shown in
It may be appreciated that the invention can be practiced with other methods for producing a rigid conduit with a reducible cross section, and can be employed by the device 100 with no change to its essential principle of operation.
Modes for Accelerating a Projectile
There are several methods through which the above device 100 can use the energy from a high velocity fluid stream to accelerate a projectile. Four methods are given below.
Buffer fluid pushing a projectile ahead of it:
In this mode, a projectile is injected into the conduit 10 with the buffer fluid, and is pushed forward by the buffer fluid. Here, both the buffer fluid and the projectile are accelerated, but it is only the kinetic energy imparted to the projectile that is of interest.
Buffer fluid directed against a projectile:
In this mode, the buffer fluid is accelerated and then directed against the projectile, so that the kinetic energy of the fluid is imparted to the projectile through a momentum transfer.
Buffer fluid pressurizing an enclosed chamber:
Here, a compressible fluid is explosively injected into an enclosed chamber such as a gun barrel, thereby raising the pressure within the chamber and expelling a projectile contained within.
Buffer fluid as the projectile:
In this mode, the device 100 behaves strictly as a pump, and the buffer fluid itself serves as the projectile.
In all of the above operation modes, the rotation of the cylinders 11, 12 may be of a constant speed, or of a pulsed or intermittent nature. When the device 100 is used as a pump, as in the last configuration, a constant speed of rotation may be preferable. However, when the device 100 is used to accelerate an object, as in the first three modes given above, an intermittent rotation which allows energy to be injected into the device 100 in a single pulse may be preferred.
An Internal Combustion Engine
It is a fundamental principle of the device 100 that if rotation can cause compression, then expansion can cause rotation. This characteristic of the device 100 allows it to function as an internal combustion engine. By introducing a second cylinder or roller into the device 100, the conduit 10 may be closed in multiple locations simultaneously. This allows a gas and fuel mixture contained within it to be selectively compressed, ignited, and decompressed in a controlled sequence before exiting the device 100. In this configuration, the cylinders are self-powered, and a transmission is used to extract torque from the device 100. Unlike a reciprocating engine or a turbine engine, a helical internal combustion engine can operate efficiently at a very small scale due to its ability to provide arbitrarily long combustion cycles, regardless of the engine's scale. With reciprocating engines and turbine engines, the time available for combustion decreases as the engine's scale decreases.
A Magnetic-Pressure Accelerator
Referring now to
A localized magnetic field 41 is generated at the surface of each cylinder 39 and is made to wrap around each cylinder 39 to form a helical or spiral pattern (helix). The pitch of this helix varies in a specific manner, from relatively low at its beginning at one end, to relatively high at its other end. When these cylinders are made to rotate in the same direction, the magnetic pressure wave that is produced by the convergence of their helical fields travels down the structures at a rate that is related to the pitch of the helixes at any particular point. In a region of low helix pitch, the pressure wave moves slowly; in a region of high pitch, the pressure wave travels more rapidly. Thus, given a fixed rotation speed, the magnetic pressure wave will move relatively slowly at the beginning of the helix and progress down it at an ever increasing rate.
Situated in the gap between the two cylinders 39 is a tube or similar containment structure 42 made of a rigid, magnetically transparent material, such as ceramic or the like. The structure 42 serves to guide and stabilize an object 43 being acted upon by the magnetic pressure wave. Alternatively, the helical magnetic cylinders 39 can be used by themselves to contain and stabilize the object 43, thereby making a separate guide unnecessary.
In another alternate configuration of the device 200, a device 210, shown in
In a variation on the preceding configuration, a magnetic-pressure accelerator 220 includes two linear magnetic structures 48 may be used, rather than a one, effectively forming a magnetic “trough” for the projectile 49, as shown in
As a further modification to the device 200, a magnetic-pressure acceleration 230 includes a third linear magnetic structure 51 is mounted on the opposite side of the helix to balance the side forces that are imposed on the helical structure by the lower magnetic structures, as shown in
As with the previous configuration, this configuration allows several magnetic structures 48, 51 to be arranged around a single rotating helix 50, making it possible to accelerate multiple objects simultaneously. When this is the case, the side forces on the helix can be balanced by arranging these magnetic structures symmetrically around the helix, thereby making it unnecessary to use a separate magnetic structure specifically for this purpose.
Elements of the preceding configurations may be combined to form yet another configuration of a magnetic-pressure accelerator 240, as shown in
In yet another configuration of a magnetic-pressure accelerator 250, as shown in
In still another possible configuration of a magnetic-pressure accelerator 260, as shown in
In a variation on the preceding configuration, a magnetic-pressure accelerator 270 is shown in
As with the other configurations, this traveling-intersection effect can be achieved through the use of a helical feature 65 and linear feature 66 in a magnetic-pressure accelerator 280 as shown in
Some, but not all, possible configurations of a helical magnetic structure used in combination with other helical or linear structures are described. Instead, this description refers to any configuration in which a helically-patterned magnetic field interacts with a magnetically responsive object in such a way that relative rotational motion between them causes the object to be either accelerated or decelerated. Additionally, this device is not limited to magnetic structures that are arranged on a cylinder, but can employ any structure which generates a helically-patterned magnetic field at the point of interaction with a magnetically responsive object, regardless of how the field is produced. For example, this device does not require the helical magnetic pattern to be geometrically continuous, but rather the pattern may be comprised of an array of multiple, discrete magnetic sources, such that the net effect upon the object is that of a helix.
Performance Parameters
The device of the invention has multiple applications, spanning a diverse range of fields, and each of these applications has its own optimal projectile characteristics. These characteristics primarily involve projectile mass, projectile velocity, and rate of fire.
Projectile mass and projectile velocity are determined by specific physical characteristics of the device itself, such as the helix surface speed (the speed at which every point on surface of the helix is traveling axially), the final helix pitch (the distance that a point on the helix advances during one rotation), and the length of the helix (the accelerating distance available). Other characteristics include the pressure field strength, or ‘flux density’, at the point of interaction with the projectile, and the size of the power source used to rotate the helix or other components.
As a result, the basic physical parameters of the accelerator can vary widely depending on its application. Indeed, one of the principle benefits of this device is its ability to be scaled up or down to virtually any power level.
Although specific requirements for each application will be addressed separately, they all share a general range of performance criteria, which allows for a generalized version of the device to be described in the following terms:
Projectile velocity: Most of the applications for this device require a projectile velocity in excess of 3 Km/sec, with some requiring velocities of up to 150 Km/sec or more. For comparison, the velocity of a typical rifle round is approximately 1 Km/sec, and the velocity of a satellite in low earth orbit is approximately 7 Km/sec. Materials research has demonstrated that a ‘universal damage criteria’ exists at an energy density of 10,000 Joules/cm2, and a projectile that is able to impart a net energy of 12,000 Joules to its target will vaporize one cubic centimeter of virtually any known material upon impact. Since many of the device's intended applications call for a complete removal of the target material, this velocity is used as a minimum benchmark for many of the projected versions.
Projectile mass: For most applications, the projectile will be traveling through air (as opposed to vacuum) during all, or part, of its flight. This requires that the projectile have a certain minimum mass to maintain its velocity through the air over the required distance. Therefore projectile mass ranges from milligrams for short range, low energy applications, to hundreds of kilograms or more for longer range and higher energy applications.
Surface speed: Due to the centrifugal forces involved, it is desirable to limit the surface speed of the helix and other rotating components to roughly 500 meters/sec (1.5 times the speed of sound) or less. However, it may be necessary to use higher surface speeds in certain applications.
Final helix pitch: Due to the above limitation on the surface speed of the rotating components, projectile velocity is largely determined by the final pitch of the helix. A helix pitch in the range of 7:1 (approximately 8°) is used in low velocity applications, and a pitch of up to 500:1 (approximately 0.11°) or greater is used in higher velocity applications.
Helix length: Since many applications require the device to be portable, a typical helix length might be in the range of 8 to 15 meters (25 to 50 ft). However, much shorter and much longer configurations can be produced for specific applications.
Magnetic flux density: The strength, or ‘flux density’, of the magnetic pressure wave determines the accelerating force that can be brought to bear on the projectile without the projectile breaking free from, and being left behind by, the traveling wave. For example, given a helix length of 8 meters, a flux density of 6.5 Tesla would be required to accelerate a 10 gram iron projectile to a velocity of 5,000 m/sec. This flux density is well within the range of existing resistive electromagnets and superconducting magnets.
Power source: Because this device uses rotational kinetic energy directly, without the need to first convert the energy into electrical form, it can be driven by a wide range of conventional power sources, including gas turbines, electric motors, and diesel engines. For example, a device that can accelerate a continuous stream of 10 g projectiles, at a rate of ten per second, to a velocity of 5,000 m/sec would require a power source of about 750 hp. A wide variety of power sources currently exist that are able to provide this level of output while still being suitably compact and inexpensive.
Applications
The following are some example applications for which the disclosed device either improves upon an existing process, or enables the creation of an entirely new field.
Borehole Drilling and Tunnel Drilling
Research funded by the Department of Energy has determined that the eventual development of hundred-kilowatt lasers will significantly decrease the cost of borehole drilling for natural gas and oil. Our device performs this application with a level of power and efficiency a full order of magnitude higher than these future lasers, and does so with currently available technology. As an example, when used for oil drilling, a version of the device powered by a 1 MegaWatt (˜700 hp.) gas turbine, electric motor, or diesel engine, could drill a 1 cm. diameter borehole through one kilometer of any type of rock in approximately 16 minutes (assuming 12 KJ/cm3). This is hundreds of times faster than with conventional drilling techniques. Since the projectiles would vaporize the rock face on impact, it would be unnecessary to remove debris. Furthermore, as with laser drilling, the resulting heat would cause a ceramic liner to spontaneously form on the borehole walls, making it unnecessary to later reinforce the borehole with a separate metal liner.
In addition to borehole drilling, the higher power and efficiency provided by our device makes it ideal for applications that remain closed to lasers in the foreseeable future, such as horizontal tunnel drilling. The device of preceding example could drill a 1 meter diameter, one kilometer long tunnel through any type of rock in approximately five days, and a 2 meter diameter tunnel in approximately 22 days. Performing such bulk material removal with a laser would be extraordinarily costly, due to a laser's inefficiency and low power output.
In applications where it is merely sufficient to pulverize the rock face, as is done in conventional tunneling, the device can be used to inscribe a progression of deep grid patterns in the rock face, rapidly granulating it for later removal by an excavator.
Materials Processing
Our device would address many of the materials processing applications that are currently envisioned for future high-powered lasers, and will do so at a fraction of the cost on a per-Watt average power basis, as well as on a cost-per-part basis. One such application is shot peening. In conventional shot peening, critical metal components, such as aircraft turbine blades and medical implants, are bombarded with small, high velocity metal or ceramic balls. The impact of these balls compresses the surface of the part, hardening it and making it significantly more resistant to wear and fractures. In laser shot peening, this surface-compression effect is achieved through the reaction force of an intermediate substance, such as water, which is driven explosively against the surface of the part as the beam passes though it. Because laser shot peening does not face the energy density limitations of conventional shot peening, it can produce compression effects that extend far deeper into the surface of the part, resulting in parts that are up to four times stronger than with ball peening. However, laser shot peening is an extremely expensive operation, and is therefore currently only projected for use in high-value, high-cost industries such as aerospace and medical manufacturing. In comparison, our device will provide greater energy density than laser shot peening at much lower cost per part, making the process accessible to high volume industries such as automobile manufacturing, which currently uses conventional shot peening.
Anti-Ballistic Missile Systems
It is easy to envision a version of this device that can accelerate projectiles with masses of tens to hundreds of grams to a velocity of 15 km/s, yet is sufficiently small and light enough to be carried under the wing of a jet fighter. When carried to high altitudes, such a device could destroy ballistic missiles in flight, and unlike laser-based anti-missile systems, it would be able to engage missiles at any point along their flight path, from launch-stage to reentry.
Likewise, a space-based anti-ballistic missile version of this device would have significant advantages over a space-based system using a laser. For a laser to maintain the necessary power-densities over the immense distances involved, an extremely large lens or mirror is required. Furthermore, the satellite that carries it will need to operate at a relatively low altitude to minimize the distance between it and the target. For example, a currently proposed design for a laser-based anti-ballistic missile system calls for a mirror that is 11-meters in diameter, carried by a satellite stationed at the relatively low altitude of several hundred miles. Achieving complete coverage of the Earth's surface from this low altitude is projected to require a continuously orbiting formation of over 1000 such satellites. In comparison, a kinetic energy weapon system does not have the fundamental distance limitations of a laser, and as a result, it can operate from a much higher altitude. In theory, only three kinetic-energy based satellites would be required to create a missile shield that provided complete coverage across the entire Earth's surface.
Other Weapons Systems
Our device would also have applications in other types of weapons systems, including:
Hypervelocity artillery
Anti-artillery guns
Anti-tactical missile guns
Close-in weapons
Satellite Launching
The possibility of using ultra-high power lasers to launch satellites has been studied since the 1960s. In laser launching, a ground-based high power laser is aimed at a specially designed launch vehicle. The laser heats fuel within the vehicle, which vaporizes and produces thrust. Since the energy for the flight is transmitted to the vehicle from the ground, the vehicle does not need to carry its own chemical energy in the form of rocket fuel. As a result, a greater percentage of the launch vehicle's weight can be devoted to payload. However, research has estimated that at least 1 MW of laser power would be required for each kilogram of launch-vehicle mass, and that hundreds of megawatts of laser power would be required to launch payloads of any practical weight. One study estimated that the capital cost of supplying this amount of continuous electrical power to such a laser would be approximately $1 per watt of generating capacity for the power plant alone. Therefore, the initial capital cost for the necessary electrical generation plant would be on the order of one hundred million dollars. The same study estimated that the focusing lens required by such a laser would cost 80 million dollars. And none of these estimates takes the capital cost of the 100-megawatt laser itself into account.
In contrast, our device scales up to this level output power far more easily than a laser, and, perhaps just as importantly, it does not require input power to be provided in the form of electrical energy. Instead, power is provided to it in the form of rotational kinetic energy. In practice, this kinetic energy would most likely be supplied by a large flywheel, which would drive the accelerator directly, without the need for an intermediate electrical conversion or any other electrical power-generation or storage stage. Flywheels of this power level are currently in use in other applications and cost hundreds of times less per Watt than an electrical power plant of similar performance.
Impact Fusion
In Impact fusion, a high velocity projectile is fired at a target made of a reactive material. The extremely high pressure of its impact results in nuclear fusion, thereby yielding more energy than was delivered to the target by the projectile itself. Although this application was originally conceived of for rail guns, the required minimum projectile velocity of 150 km/s, combined with the mega-joule kinetic energy level, has proven to be far beyond their capability, or any other similar accelerator technology to achieve. A version of our device having the appropriate combination of helix length, helix pitch and rotational velocity could conceivably be constructed to meet the requirements of high projectile velocity, high kinetic energy, and continuous fire, opening a new field of alternative energy production.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.
This application claims the benefit of U.S. Provisional Application No. 60/514,487, filed Oct. 24, 2003, the entire contents of which are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60514487 | Oct 2003 | US |
