Method and apparatus for shockwave attenuation via cavitation

• US 8,740,071 B1
• Filed: 04/17/2012
• Issued: 06/03/2014
• Est. Priority Date: 11/22/2011
• Status: Expired due to Fees

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Tillotson, Brian J., Higgs, Christopher
• Primary Examiner(s): Savusdiphol, Paultep
• Application Number:
  US13/449,025
• Time in Patent Office: 777 Days
• Field of Search: 235/400, 235/401, 235/412, 235/413
• US Class Current: 235/412
• CPC Class Codes: F41H 11/02 Anti-aircraft or anti-guided missile or anti-torpedo defence installations or systems cartridges or missiles for producing smoke or for dispensing radar chaff or infrared material F42B5/15, F42B12/48, F42B12/70; informative reference: details of radar or sonar systems G01S7/00; jamming or electronic countermeasures G01S7/38, G01S7/495, H04K3/00
• 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. The method and system may include providing a sensor for detecting a shockwave-producing event, which may include detecting an explosive device or detecting an explosion from an explosive device, determining a direction and distance of the shockwave relative to a defended target, calculating with a computer control a firing plan, and interposing a second medium between the shockwave and a protected asset if cost effective to do so. The second medium may be different from the first medium and the shockwave may be reflected, refracted and dispersed, or absorbed as it passes through the second medium prior to reaching the protected asset, and thus may be attenuated in force as it reaches the protected asset.

Claims

1. A shockwave attenuation system, comprising:

a sensor configured to generate a detection signal based on at least one of detecting an explosion capable of producing a shockwave and predicting an explosion from an explosive device that is capable of producing the shockwave;

a projectile launcher configured to launch projectiles in a pre-set quantity and direction; and

a computer configured to receive the detection signal and activate the projectile launcher to deliver at least one projectile to a body of water adjacent a protected asset, the at least one projectile being delivered at a location and in a manner that creates a cavitation region between the shockwave and the protected asset such that the shockwave contacts the cavitation region and is attenuated in energy density before it reaches the protected asset.

2. The system of claim 1, wherein the protected asset is a waterborne asset.

3. The system of claim 1, wherein at least one of the sensor, the projectile launcher and the control is mounted on one of the protected asset, another waterborne asset, or adjacent the body of water.

4. The system of claim 1, wherein the shockwave is generated by the explosive device.

5. The system of claim 4, wherein the explosive device is one of a torpedo, a naval mine, a depth charge, a missile, a bomb, and a ballistic shell.

6. The system of claim 1, wherein the projectile launcher is configured to launch a projectile having a size, velocity and trajectory sufficient to form the cavitation region in the body of water to have a shape and position to at least one of at least partially reflect the shockwave, refract the shockwave, absorb energy from the shockwave, and slow the velocity of the shockwave toward the protected asset.

7. The system of claim 1, wherein the projectile launcher is one of a machine gun, a chain gun and a rocket launcher.

8. The system of claim 7, wherein the projectile launcher is configured to launch a plurality of projectiles to create a plurality of cavitation regions in the body of water adjacent the protected asset and in a path of the shockwave.

9. The system of claim 1, wherein the projectile launcher is configured to launch at least one of a regular bullet, shot, a sabot-mounted lightweight bullet, a set of pellets, a plurality of flechettes, and a bullet that fragments upon impacting the body of water.

10. The system of claim 1, wherein the sensor is configured to detect at least two bands of electromagnetic radiation generated by the explosion.

11. The system of claim 1, wherein the sensor is configured to detect at least one of the shape, trajectory and speed of an incoming threat containing the explosive device to calculate a signature of the incoming threat.

12. The system of claim 11, wherein the sensor is further configured to detect at least one of a location of the explosion, a time of the explosion, and a magnitude of the explosion.

13. The system of claim 12, wherein sensor detection is used to calculate an intercept region, the at least one projectile being launched by said projectile launcher to create the cavitation region.

14. The apparatus of claim 13, wherein the protected asset is one of a surface vessel, a submarine, and an offshore platform, and wherein the intercept region is determined based on one or more vulnerabilities of the protected asset.

15. 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; and

launching with a projectile launcher at least one projectile in a direction so the projectile enters a body of water adjacent a protected asset in a manner that creates a cavitation region between a shockwave from the explosion and a protected asset such that the shockwave contacts the cavitation region and is attenuated in energy density before it reaches the protected asset.

16. The method of claim 15, wherein detecting includes detecting with a sensor at least two bands of electromagnetic radiation from the explosion.

17. 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;

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 related to a projectile launcher to launch a projectile into a body of water adjacent the protected asset; and

if the firing plan determines that it is cost effective to execute the firing plan in view of a cost to operate a projectile launcher and probable cost of damage from a shockwave from the explosion, launching with the projectile launcher at least one projectile in a predetermined direction so the projectile enters the body of water in a manner that creates a cavitation region between a shockwave from the explosion and the protected asset such that the shockwave contacts the cavitation region and is attenuated in energy density before it reaches the protected asset.

18. The method of claim 17, 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 a known explosive device, motion of the incoming threat, and the shape, orientation and motion of the protected asset; and

making a determination to counter the incoming threat or not to 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 related to the projectile launcher with respect to attenuating shockwaves from the estimated explosion magnitudes and locations.

19. The method of claim 17, wherein detecting includes

measuring a signature of the explosion from the explosive device;

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

determining a probability the incoming threat is one of the plurality of different explosives; 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 a known explosive device, motion of the incoming threat, and the shape orientation and motion of the protected asset; and

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

20. The method of claim 17, wherein detecting an explosion includes detecting at least two bands of electromagnetic radiation generated by the explosion.