Powder material dispenser attached to an external station of an aircraft

Abstract

A dispenser of powder material designed to be attached to an aircraft is described. The device should be able to release large quantities of material within seconds, from a platform potentially flying at high speed and high altitude. A potential application is in the framework of a concept of defense against hypersonic missiles featuring atmospheric dispersal of abrasive material on the expected path of the incoming threat. The powder material is stored in one or several cylindrical volumes from which openings allow the material to exit. A moving part fitted inside the cylinder separates the volume into compartments. The rotational movement of the moving part inside the cylinder brings the material contained in each compartment to the exit at a controlled rate, depending on the speed of rotation. The device may be designed to be attached to standard weapon stations of an aircraft or to purpose-built hard points.

Description

Powder Material Dispenser Attached to an External Station of an Aircraft

[0001] The present disclosure relates to a device intended to release powder material in the atmosphere. In the specific application described, it is a component of an air defense system which is itself based on the concept of “Defense against hypersonic vehicles by atmospheric dispersal of abrasive material”, described in a separate invention.

[0002] Although the specific application described is in the framework of a concept of defense against hypersonic missiles, the atmospheric release of powder material is not limited to that purpose.

[0003] The atmospheric dispersal of abrasive material has been proposed as a new defense concept against aerial threats, and especially hypersonic vehicles (see Canadian patent application CA-3264406). It aims to temporarily affect the environment in a wide area around the expected path of an incoming vehicle moving at or close to hypersonic velocity in a way that renders displacement at such velocities unsuitable, therefore leading to the abrupt degradation and ultimate destruction of the vehicle. This is done through the atmospheric dispersal of finely divided refractory material, whether sand, basalt ash, metal fragments or any material whose composition, density, grain size and shape is chosen and optimized for its ease of atmospheric dispersion, residence time in air, abrasive power at elevated temperatures or a combination thereof. The concept focuses on actuation of the payload release from a vector at least several seconds before the arrival of the incoming threat and affecting a large cross section around its expected path, therefore reducing the need to precisely determine the point of encounter (in time and space) between the threat and the interceptor.

[0004] In several of the proposed embodiments of this concept, powder material is released by one or several dispensers fitted on a manned or unmanned aircraft. This generally requires the release of large quantities of material at a high altitude, close to the operational ceiling of the aircraft, and potentially at high velocity, including in the supersonic range.

[0005] Aircrafts are often used to spray or dust croplands, forests and other land areas with material such as chemicals, fertilizers, seeds or fire suppressants that could be in solid form. Unlike the dispersal of powder material in a volume of air at potentially high altitude as required for the application of interest of the present invention, the applications reported above relate to the spreading of material over large areas on the ground, from a relatively low altitude, typically by a slow-moving aircraft. This includes applications ranging from crop dusting to firefighting and even chemical or biological warfare contamination or de-contamination operations. The only exception may be the large-scale dispersal of solid nucleation particles for climate control, but this implies a release over large zones rather than the rapid and localized release of large quantities of material in a specific volume. This could be carried out with well-known classical methods involving conveyors fitted in the cargo bay of an aircraft and do not require specific developments or inventions.

[0006] For operational purposes in the framework of an air-defense system, it is also important to have a device that could be rapidly attached to a flying platform as well as reloaded or replaced from a reusable platform after use. A system fully integrated in a dispenser that could be attached to or detached from the external pylons of an aircraft would bring a considerable flexibility.

[0007] A dispenser is typically defined as an automatic machine or container which is designed to release a specific amount of something. The two primary functions are therefore to store material and to release it in a controlled way.

[0008] In the present invention, one or several dispensers are fitted on hard points of an aircraft, used as reusable flying platform. The dispenser features one or several cylindrical volumes in which the powder material is stored. Each cylindrical volume contains a moving part, either a paddle wheel, a screw or a hybrid version of those, separating the cylindrical volume in different compartments. Once the moving part is set in rotational motion, the different compartments and their content move around the central axis and align, sequentially, with an opening from the cylinder. The content of each compartment is then released in the air by the combination of the centrifugal motion and the flow of air in the air channel leading to the exhaust from the dispenser.

[0009] schematically illustrates sectional views of potential embodiments of the invention corresponding to a single (left) or double (right) cylindrical volumes. The device consists on an external envelope (1), fixtures to the flying platform, for example a pylon (2), moving parts which could be screws or paddle wheels (3) fitted inside a cylindrical volume (4), from which optionally closeable openings (5) allow the powder material (6) stored in different compartments to exit once the moving parts are in controlled rotational motion. The material release can be done directly from the opening(s) (5) or through air channels (7) in the device, from an air intake to one or several exits (not represented). The embodiment on the right enables a better mitigation of mass imbalance during the release process.

[0010] schematically illustrates a paddle wheel representing paddles (8) and sectional separations (9) that together define compartments (10). The number of sectional separations and paddles, as well as their shape and curvature, are illustrative.

[0011] schematically illustrates a technical option to simultaneously control the openings in two cylinders (5) and in the external envelope (11). The figure on the left is in closed configuration, and the figure on the right in open configuration. The option features four sets of panels, two for the openings from the cylinders (12) and two for the exhaust from the envelope (13), linked by four sets of hinges: one at a fixed location (14), one that can move along the vertical axis (15) and two that are free (16). When hinge (15) is raised, all gates are open simultaneously. Note that it is preferable to raise (15) rather than lower it in order to avoid protuberance that could compromise aircraft landing.

[0012] schematically illustrates a close-up of the edge of a paddle (3) in one potential design featuring a terminal section with an increased angle (17) with the surface of the cylinder (4), which is intended to mitigate the accumulation of powder material between the paddle and the cylinder during rotation, which would risk clogging the wheel.

[0013] represents the Object-Process Diagram, consistent with conventions in ISO standard 19450, of the operation of the device described in the present invention and its operating platform. The material release vector is made of the flying platform (the aircraft) and one or several dispensers as described in the present invention (“The Device”). Moving parts typically consist in the screw(s) or wheel(s) fitted in the cylindrical volume(s). It may also include the optional presence of activable gates to control the aperture enabling the material to exit the cylindrical volume and / or creating air flow in specially designed channels in the device. The source of energy can either be fitted in the device or in the flying platform, with suitable power transmission at the interface.

[0014] Requirements

[0015] The device should be able to release in the air large quantities of material (from kilograms to metric tons) within seconds. Such material may consist of small grains, fibres, fragments, flakes or foils of metal, sand, glass, ceramics or other material, which will be referred to herein as “powder material”. The atmospheric release should be carried out at high speed, taking into account aerodynamic considerations and turbulence during release, as well as potential effect of acceleration on the perceived gravitational drag.

[0016] The device and the platform should be reusable. For a flexibility of employment, the device should be useable with different types of platforms (aircrafts) and enable re-fitting with a new, ready-to-use, device within a short time. In a preferred embodiment of the invention, the device should be attached to an aircraft by its standard external pylons, implying that the material storage should be integrated with the release mechanism.

[0017] Another important consideration is to avoid mass imbalance during the release process.

[0018] The external envelope of the device should be designed to avoid excessive drag during flight and prevent drag increase during release.

[0019] From the considerations above, the device described in the present invention features a forced-release mechanism integrating material storage. Powder material would be stored in different compartments of one or several cylindrical volumes, the compartments being defined by the shape of an object fitted inside the cylinder and that could rotate around its central axis. This could be a screw, a paddle wheel or variants thereof. The different compartments would therefore be mobile, depending on the rotational motion of the screw or wheel, leading to the material they contain towards an exit from the cylinder.

[0020] The release mechanism and the rotational motion of the screw or wheel, as well as the optional opening of one or several gates creating an exit from the cylinder and / or an air channel, are controlled by the external sub-system that provides guidance to the platform. This is considered to be outside of the scope of the present invention.

[0021] Key Considerations – Material Release

[0022] A dispenser is typically defined as an automatic machine or container which is designed to release a specific amount of something. The principal considerations for the material release in the framework of the present invention are 1) a complete release of the stored amount of material in a relatively short time, and 2) at a rate that should be controllable. The technical option proposed is to store the material to release in a cylindrical volume from which one or several openings allow the material to exit. A moving part fitted inside the cylinder separates the volume into compartments. The rotational movement of the moving part inside the cylinder brings the material contained in each compartment to the exit at a controlled rate, depending on the speed of rotation.

[0023] The first embodiment to consider for the moving part is a screw. Once the screw is in motion, the thread leads the powder material towards one end of the cylinder at a controllable rate. This option has the drawback that during the release process, the center of gravity of the stored material moves towards the end of the cylinder. This could be considered if there is sufficient margin for mass imbalance. It should also be highlighted that separation of powder material with a screw could only be practical with a type of aircraft providing relatively small accelerations compared with earth gravity, otherwise the material would move in the cylinder in an un-controlled manner.

[0024] The second embodiment involves the separation of the cylindrical volume into compartments with separations in two directions: axial, along the central axis of the cylinder, and radial, perpendicular to the axis. This is the option represented in, with a paddle wheel in which the paddles form axial separations and sectional disks provide radial separations. Once in motion, the wheel would bring the different compartments along an open sector of the cylinder, releasing the material contained in the corresponding compartments.

[0025] A hybrid option between the paddle wheel and the screw would be a double-threaded screw, with superposed inverted threads, forming diamond-shaped compartments around the axis.

[0026] Ideally, the shape of the paddles should be designed to ease the expulsion of the material from the compartment. The shape of the paddles represented in Figures 1 and 2 is an example of such features, although other variants are possible without departing from the spirit of the invention. One potential adaptation is represented on, in which the edge of the paddle has an increased angle with the inner surface of the cylinder in order to mitigate the risk of clogging of the wheel by accumulation of material during rotation. Note that the main part of the paddle and the terminal section at the edge may be in different materials.

[0027] The speed of rotation of the wheel can be set so that the sequential release of material from the different compartments corresponds to the expected duration of the process, or slightly less, optionally followed by a significant acceleration of the rotation to force potentially remaining material out of the device.

[0028] The powder material could be ejected from the cylinder directly outside of the device (as on the left figure in) or indirectly through a channel between an air intake and one or several exhaust. The aperture of the air intake, exhaust and / or exit from the cylinder(s) can be permanently open or actionable to be opened only slightly before release. This last option would bring complexity to the overall design but allows for better control of the powder material environment during storage. A potential option for the synchronized opening of the different gates in the device is schematically illustrated in

[0029] Key Considerations –Impact on flying performance of the aircraft

[0030] The dispenser should be designed so that it has a minimal impact on the flying performance of the aircraft. Besides the balance of mass already considered previously, another aspect to take into account is the aerodynamic drag of the external envelope. This aspect was not taken into account for devices fitted on slow-moving platforms, such as the system described US 9,346,545.

[0031] In addition to the aerodynamic characteristics of the envelope, the drag increase during the release process should be minimized to avoid excessive mechanical shocks on the device, the pylon and / or the aircraft hardpoint in-flight.

[0032] Finally, the release process, for example gates opening, should not create protuberance of the device that would exceed clearance for a safe flight and landing.

[0033] Key Considerations – Interfaces with other systems

[0034] Most of the interfaces are with the flying platform, the aircraft, through the hard point. This includes the mechanical fixture and potentially power provision.

[0035] The order to release powder material is provided by an external command and control system. However, this system also directly interacts with the flying platform for guidance towards the point of release, as well as with other platforms and sensors for threat detection, identification, and other functions necessary for the overall air-defense process. Ideally, the communication system with the command and control will be incorporated with the flying platform, and the order(s) to trigger the release process transmitted from the platform to the device through the cabling at the physical interface.

[0036] Key Considerations – Cost considerations

[0037] In its primary use, the present invention is a component of an air-defense system. Compared with the operation of expandable interceptors, the employment of a reusable aircraft as platform to release and disperse material in the atmosphere already represents a significant potential for cost reduction.

[0038] Even with a reusable flying platform, the dispenser(s) can either be disposable or re-fillable. Despite the increased complexity of design related to refill operations, it is assessed that this option would be more cost effective, especially since a filled canister would likely have a finite shelf-live due to potential moisture ingress in the powder material storage compartments. Besides, in addition to the actual threat level at a given site, the number of dispensers expected to be used in operation should include a certain number of devices employed for live exercises.

[0039] Key Considerations – Dispenser maintenance and refill

[0040] As mentioned previously, the ability to refill the dispenser after usage is a significant feature of cost effectiveness. This could be done either by dedicated openings on the side(s) or top of the device, combined with the controlled rotation of the wheel to fill the different compartments sequentially, or by turning the device upside-down and re-filling the compartments from the exhaust opening. Alternatively, empty cylinders including the moving part may be removed altogether from the front or rear and replaced by a full cylinder.

[0041] Whether the device can be refilled or not after usage, a certain level of maintenance and verification that the device remains fit for service is important. This relates to aspects including the mobile parts not being gripped, the charge of the battery or the performance of the motor, potentially by disconnecting it from the wheel axis and running at regular intervals.

[0042] A specific aspect of the device operationality is the physical integrity of the powder material and especially avoiding that the powder forms compact blocks. This could potentially be affected by the level of moisture in the compartments. Features mitigating moisture ingress such as air-tight barriers (inside of the device or enveloping the whole device during storage) and / or actively absorbing components should be considered, and their integrity verified on a regular basis.

[0043] Key Considerations – Assessment of Prior Art

[0044] Systems used for the current applications of powder material release from an aircraft, such as crop dusting, typically use spreaders attached to a gate box at the base of a hopper or sifter, which can be located inside of the fuselage (as described in US 9,173,337) or mounted on external structures such as for example the spray boom of aircrafts normally used for spraying liquids (as described in US 9,346,545). These systems use gravity to allow the powder material to leave the hopper or sifter, in which it is stored, and geometrical constraints (shape of the equipment, opening of aperture and / or presence of a grid) to limit and control the flow. These options can hardly be applied if large quantities of material are to be released in a very short time, and especially if it is released from a fast-moving aircraft.

[0045] Unlike the system described in US 9,346,545, the material storage in the present invention is combined with the release mechanism. It doesn’t include a separate sifter and relies on specifically designed wheels having both the functions of storage before release and control of release flow.

[0046] Similarly, unlike the system described in US 9,173,337, the present invention doesn’t feature a hopper separated from the spreader mechanism by a gate box. Also, the guidance of the aerial platform and the control of the release mechanism are provided by a dedicated dynamic system linked to a range of sensors rather than a pre-programmed pattern compared to data from a global navigation satellite system. A satellite-based positioning system may be one component of the sensors used by the guidance system to improve the 3D picture of the environment and especially the position of the vector relative to the incoming threat but would not be used directly to guide the vector or actuate the release mechanism.EXAMPLES

[0047] In the following description, the invention will be discussed primarily as a means to counter incoming hypersonic threats in the framework of the operational employment of the concept described in a related invention. It is to be understood that the present invention is not limited to this application and would also cover the design and use of a similar device for other purposes.

[0048] In a preferred embodiment, a powder material dispenser would be designed to be attached to the standard under-wing and / or underbody hardpoints, or weapon stations, of a military aircraft.

[0049] An exemplary employment of this variant would consist in the use of the device in combination with a decommissioned fighter jet equipped with a remote-control kit and typically used as target for training, such as the QF-16, that could be used as unmanned vector. It can carry an external payload of 2,000 lbs under each wing. Such a platform could loiter at subsonic speed for a significant amount of time and reach the powder material release area in full after-burner at up to Mach 2 upon request, releasing between 1 and 2 metric tons of powder material on a 1 km long section in about 2 seconds. In this configuration, the powder material could be released at an altitude of up to 50,000 ft (15 km), the service ceiling of this kind of platform. After release, the platform would go back to base and be refitted with one or several new dispensers, and be operational again. This exemplary employment would be complementary to classical air-defense systems based on interceptors for the defense of land-based assets against long-range strategic vectors.

[0050] In another exemplary employment of the embodiment, one or several devices could be attached to specially designated carrier-borne aircraft, including a potential remote-controlled QF-18 version similar to the QF-16 mentioned previously, or be part of the standard payload of carrier-based patrol aircraft. Such platforms would be capable to deploy a screen of powder material at low altitude, between the aircraft carrier and an identified enemy launch platform for short-range hypersonic cruise missiles, once launches have been detected, in order to protect the asset against a salvo of missiles that would otherwise be challenging for point defenses.

[0051] In another embodiment, powder material dispensers could be fitted to purpose-designed drones that would be deployed as fleets of long-lasting loitering platforms, depending on the threat level. Such platforms may not be as responsive and flexible as fast-moving aircraft but would be deployed in larger number, being able to disperse material in a larger volume of atmosphere. A variant of this embodiment would be a drone design incorporating, or built around, a powder material release device.

[0052] In the different embodiments described above, the airborne platform may be equipped, in addition to the powder dispensers, with sensors that would complement the ground- and / or space-based sensors of the wider air defense system. It may also be fitted with air-to-air weapons to counter subsonic or supersonic threats. These additional features highlight the integration of the system in a broader air and missile defense architecture and the synergies that can be exploited.

[0053] It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the application presented may be combined with each other arbitrarily without conflict.

Claims

A device to release and disperse powder material in the atmosphere, designed to be attached to one or several external stations of an airborne platform, comprising:At least one screw or paddle wheel (collectively called “wheel”) fitted in a cylindrical shape casing, separating the cylindrical volume in several compartments in which the powder material is stored and sequentially released while the wheel is put in motion around its central axis and in which the rate of powder material release is controlled by the speed of rotation,At least one motor to put the wheel(s) in rotational motion at a controlled speed,Interfaces with the airborne platform.The device of claim 1 in which the powder material is released in one or several internal channels between an air intake and exhaust, which can optionally be closed before the release mechanism is activated.The device of claim 1 or 2 where the source of power is integrated with the device.The device of any claim 1 to 3 where the powder material consists in small grains, fibers, fragments, flakes or foils of metal, sand, glass, ceramics or other finely divided material.The device of any claim 1 to 4 with a storage capacity ranging from kilograms to metric tons of material.The device of any claim 1 to 5 where the airborne platform is a manned or unmanned fixed-wing aircraft.The device of any claim 1 to 6 where the release mechanism can be activated remotely.The device of any claim 1 to 7 where the interface with the airborne platform includes the control of the release mechanism.The device of any claim 1 to 8 where the interface with the airborne platform includes provision of power.The device of any claim 1 to 9, equipped with means to prevent or mitigate moisture ingress during storage.The device of any claim 1 to 10 where the fixture to the station is a standard support structure used for ordnances or external fuel tanks on a pylon, that enable the device to be easily attached to and detached from different aircrafts.The device of any claim 1 to 10 where the airborne platform is purpose-built to incorporate the device.The device of any claim 1 to 12, equipped with means to refill the device with new material after usage.A system to operate the device and the platform described in any claim 1 to 13.A system to carry out the maintenance of the device described in any claim 1 to 13.A system to refill the device described in claim 13.

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