Method and system for shockwave attenuation via electromagnetic arc

• US 8,981,261 B1
• Filed: 05/30/2012
• Issued: 03/17/2015
• Est. Priority Date: 05/30/2012
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Tillotson, Brian J.
• Primary Examiner(s): PELHAM, JOSEPH MOORE
• Application Number:
  US13/483,995
• Time in Patent Office: 1,021 Days
• Field of Search: None
• US Class Current: 219/383
• CPC Class Codes: F41H 13/0093 Devices generating an electromagnetic pulse, e.g. for disrupting or destroying electronic devices
• CPC Class Codes: F41H 5/007 Reactive armour; Dynamic armour
• CPC Class Codes: F42D 5/045 Detonation-wave absorbing or damping means

Abstract

A method and system for attenuating a shockwave propagating through a first medium by heating a selected region of the first fluid medium rapidly to create a second, transient medium that intercepts the shockwave and attenuates its energy density before it reaches a protected asset. The second medium may attenuate the shockwave by one or more of reflection, refraction, dispersion, absorption and momentum transfer. The method and system may include a sensor for detecting a shockwave-producing event, determining a direction and distance of the shockwave relative to a defended target and calculating a firing plan, and an arc generator for creating the second medium. The arc generator may create the second medium by creating an electric arc that travels along an electrically conductive path utilizing at least one of high intensity laser pulses, pellets forming a conductive ion trail, sacrificial conductors, projectiles trailing electrical wires, and magnetic induction.

Claims

1. A shockwave attenuation system, comprising:

a sensor for generating a detection signal based on at least one of detecting an explosion capable of producing a shockwave traveling through a first fluid medium to a protected region, and estimating a location and time of the explosion, and detecting an explosive device and estimating a location and time of an explosion from the explosive device that is capable of producing the shockwave traveling through the first fluid medium; and

an arc generator in communication with the sensor for receiving the detection signal therefrom, and in response thereto heat a selected region of the first fluid medium rapidly to create a second, transient medium, different from the first medium, interposed between the shockwave and the protected region such that the shockwave contacts the second, transient medium and is attenuated in energy density before it reaches a protected asset in the protected region.

2. The system of claim 1, wherein the second medium differs from the first medium in at least one of temperature, density and composition.

3. The system of claim 1, wherein the arc generator heats the region of the first fluid medium to create the second medium by using one of an electric arc, a laser-induced arc and a microwave-induced arc.

4. The system of claim 1, wherein the arc generator includes a power supply, and the arc generator rapidly creates the second medium by creating an electrically conductive path from the power supply to the selected region and back to the power supply.

5. The system of claim 4, wherein the arc generator creates the electrically conductive path utilizing at least one of high intensity laser pulses to form a laser-induced plasma channel (LIPC), pellets that leave a conductive trail of ions, sacrificial conductors, projectiles trailing electrical wires fired along converging paths, magnetic induction utilizing flexible channels of ionized air, and magnetic induction utilizing substantially rigid conductors.

6. The system of claim 1, wherein the protected region includes at least one protected asset, and at least one of the sensor and the arc generator is mounted on the protected asset.

7. The system of claim 1, wherein the sensor detects at least two bands of electromagnetic radiation generated by the explosion.

8. The system of claim 1, wherein the sensor detects at least one of a shape, trajectory and speed of an incoming threat containing the explosive device, and to calculate a signature of the incoming threat, the sensor also using the signature to determine likely explosion characteristics of the explosive device.

9. The system of claim 8, wherein the explosion characteristics include at least one of a location of the explosion, a time of the explosion, and a magnitude of the explosion.

10. The system of claim 9, wherein the sensor uses the explosion characteristics to calculate a location of the selected region.

11. The system of claim 6, wherein the protected asset is one of a surface vessel, a submarine vessel, an offshore platform, a land vehicle, a land structure, and a human, and wherein the sensor determines the selected region based on one or more predetermined vulnerabilities of the protected asset.

12. The system of claim 1, further comprising multiple arc generators, each connected to the sensor.

13. The system of claim 12, wherein the multiple arc generators are adapted to be mounted on a protected asset.

14. The system of claim 1, wherein the first fluid medium is ambient air, and the arc generator utilizes at least one of electric, microwave and laser energy to produce at least one of relatively hot and ionized air to form the second, transient medium in the selected region, such that the shockwave contacts the second, transient medium and is attenuated in energy density by at least one of reflection, refraction, absorption, momentum transfer and magnetic induction.

15. A method of attenuating a shockwave, the method comprising:

detecting with a sensor at least one of an explosion capable of producing a shockwave traveling through a first fluid medium to a protected region, and an explosive device;

estimating a location and time of the explosion of the at least one of an explosion from the explosive device and the explosive device that is capable of producing the shockwave;

generating a detection signal by the sensor in response to detecting at least one of the explosion and the explosive device;

heating a selected region of the first fluid medium rapidly to create a second, transient medium, different from the first medium, by an arc generator in communication with the sensor, in response to the detection signal, the second medium being interposed between the shockwave and the protected region such that the shockwave contacts the second, transient medium and is attenuated in energy density before it reaches the protected region.

16. The method of claim 15, wherein the second, transient medium attenuates the energy density of the shockwave by at least one of reflection, refraction, absorption, momentum transfer and magnetic induction.

17. The method of claim 15, wherein detecting includes detecting, with one or more sensors, at least two bands of electromagnetic radiation from the explosion.

18. The method of claim 15, wherein heating includes rapidly creating the second medium by creating an electrically conductive path from a power supply to the selected region and back to the power supply.

19. The method of claim 18, wherein creating an electrically conductive path utilizes at least one of high intensity laser pulses to form a laser-induced plasma channel (LIPC), pellets that leave a conductive trail of ions, sacrificial conductors, projectiles trailing electrical wires fired along converging paths, magnetic induction utilizing flexible channels of ionized air, and magnetic induction utilizing substantially rigid channels of ionized air.

20. A method of attenuating a shockwave, the method comprising:

detecting with a sensor at least one of an explosive device and an explosion from the explosive device;

estimating a location and time of the explosion of the at least one of an explosion from the explosive device and the explosive device and predicting an explosion therefrom that is capable of producing the shockwave;

calculating with a computer a firing plan based upon at least one of data and models of vulnerability of a protected asset, and at least one of data and models of effectiveness of actuating an arc generator to heat a selected region adjacent the protected region; and

if the firing plan determines that it is cost effective to execute the firing plan in view of a cost to operate an arc generator and probable cost of damage from a shockwave from the explosion, actuating the arc generator to heat a selected region of a first fluid medium rapidly to create a second, transient medium, different from the first medium, the second medium being interposed between the shockwave and the protected region such that the shockwave contacts the second, transient medium and is attenuated in energy density before it reaches the protected asset.

21. The method of claim 20, wherein detecting includes

measuring a signature of an incoming threat carrying the explosive device;

comparing the signature with known signatures of a plurality of different threats;

determining a probability the incoming threat is one of the plurality of different threats; and

calculating includes estimating a probability distribution function of explosion magnitudes and locations relative to the protected asset based on at least one of stored data about the type of explosive device, measured motion of the incoming threat, and a shape, relative orientation and relative motion of the protected asset; and

making a determination to counter the incoming threat or not counter the incoming threat, based on one of stored data and models of vulnerability of the protected asset to shockwaves, and data from at least one of data and models of performance of the arc generator with respect to attenuating shockwaves from the estimated explosion magnitudes and locations.

22. The method of claim 20, wherein detecting includes

measuring a signature of the explosion from the explosive device;

comparing the signature with stored signatures of a plurality of known different explosive devices;

determining a probability the explosion is from one of the plurality of known different explosive devices; and

calculating includes estimating a probability distribution function of explosion magnitudes and locations relative to the protected asset based on at least one of stored data about the type of explosion, the location of the explosion and the shape, relative orientation and relative motion of the protected asset; and

making a determination to counter the explosion or not counter the explosion, based on one of stored data and models of vulnerability of the protected asset to shockwaves from the explosion, and data from at least one of data and models of performance of the arc generator with respect to attenuating shockwaves from at least one of an estimated explosion magnitude and location.

23. The method of claim 20, wherein calculating includes calculating with a computer a firing plan based upon at least one of data and models of vulnerability of the protected asset within a protected region.