Method for reducing violence of accidental explosions in solid fuel rocket motors and other energetic devices

Abstract

A method and system for reducing the violence of an accidental explosive reaction of an energetic material, the method comprising: (a) obtaining a solid energetic material configured for use within an energetic device, the energetic material comprising at least one void formed therein; and (b) filling at least a portion of the at least one void with an inert, incompressible material configured to mechanically stabilize the energetic material to prevent the void from collapsing and the surface area of the energetic material from increasing in the event of an insult tending to damage the energetic the material. In one exemplary embodiment, the inert, incompressible material is configured to temporarily modify the energetic device, meaning that the inert, incompressible material is configured to be removably inserted or otherwise applied to the energetic device.

Description

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser. No. 60/579,938, filed Jun. 14, 2004 and entitled, “Method of Reducing Vulnerability and Violence of Explosive Response to Solid Rocket Motors,” which is incorporated by reference in its entirety herein.

FIELD OF THE INVENTION

The present invention relates to explosives and various energetic devices, such as solid fuel rocket motors, comprising an energetic material or explosive medium. More particularly, the present invention relates to various methods and systems for reducing the violence or intensity of accidental explosion of all or a portion of the energetic material or explosive medium within such energetic devices, which accidental explosion is triggered by an insult of one or more types, such as a thermal or mechanical insult, that occurs while handling, storing, or transporting the energetic device, or during other activities involving the energetic device.

BACKGROUND OF THE INVENTION AND RELATED ART

Energetic devices, or explosive devices, comprise an energetic or explosive material or medium supported therein that is configured to release, upon ignition, a highly concentrated amount of energy within a defined area for one or more intended purposes. One example of a common energetic device is a solid fuel rocket motor, which comprises a molded energetic material, typically in the form of a propellant, designed to ignite and power the rocket. The molded energetic material is also typically configured to comprise one or more simple or complex geometric structures or voids, such as a central bore formed therein, fins, cutouts, etc., designed to enhance the burn rate of the energetic material. However, these structures or voids tend to make the energetic material susceptible to collapse upon localized internal pressurization, thus potentially creating additional burning surfaces that can increase the violence, or rather the intensity, of an explosion. The violence or intensity of an explosion can be mild if the combustion is limited to the outer surface of the energetic material, moderate if damage allows convective burning by gas flow through the porous damaged energetic material, and extreme if deflagration-to-detonation occurs from the convective mode to a fully developed shock wave.

Solid fuel rocket motors and other similar energetic devices comprise many different types. In addition, all energetic devices containing energetic materials are required to undergo a hazard classification to determine the requirements necessary for the safe transportation, storage, and handling of the particular type of energetic device. The U.S. Department of Transportation has defined these classifications, wherein energetic devices are typically classified as Class I Explosives. Due to the several different types of explosives currently on the market, there are further defined several divisions within the Class I Explosives classification. Currently, there are six different divisions, each one determined by the anticipated risks or hazards associated with a particular explosive. These divisions have been defined in light of the results obtained upon subjecting the various explosive materials to standardized tests designed to determine their propensity for various types of explosions or reactions under specific accident scenarios. The six divisions and their corresponding definitions are identified below.

Division 1.1 explosives comprise a mass explosion hazard. A mass explosion is one which affects almost the entire load instantaneously.

Division 1.2 explosives comprise a projection hazard but not a mass explosion hazard.

Division 1.3 explosives comprise a fire hazard and either a minor blast hazard or a minor projection hazard or, both but not a mass explosion hazard.

Division 1.4 explosives present a minor explosion hazard. The explosive effects are largely confined to the package and no projection of fragments of appreciable size or range is to be expected. An external fire must not cause virtually instantaneous explosion of almost the entire contents of the package.

Division 1.5 explosives are those that are very insensitive. This division is comprised of substances which have a mass explosion hazard but are so insensitive that there is very little probability of initiation or of transition from burning to detonation under normal conditions of transport.

Division 1.6 explosives comprise extremely insensitive articles which do not have a mass explosive hazard. This division is comprised of articles which contain only extremely insensitive detonating substances and which demonstrate a negligible probability of accidental initiation or propagation.

The explosive potential of an energetic device, namely its propensity for explosion and the potential violence or intensity resulting from such an explosion, will determine its classification in the above-identified divisions. As can be seen, those explosives that are associated with the greatest hazards, from a handling and storage perspective, are categorized as Division 1.1 explosives. Therefore, from a manufacturer's standpoint, the lower the division in which an explosive device may be categorized, the higher the costs and more restrictive the imposed requirements will be for handling and storing that particular explosive device. In addition, the lower the division, the greater danger there is to equipment and personnel in the event of an accidental explosion.

During even carefully deliberative handling and storage of energetic or explosive devices, there still remains a risk of accident that may result in hazardous ignition of the explosive material contained within the energetic device. Indeed, the energetic device may be inadvertently subjected to one or more types of insults, such as mechanical or thermal insults. Both mechanical and thermal insults typically function to mechanically or structurally damage the energetic material, which effectively increases the surface area of the energetic material, thus potentially increasing the reaction violence or reaction intensity in the event of an accidental or inadvertent ignition, resulting in an explosion involving the energetic material. One common type of thermal insult is accidental fire, such as that caused by spilled and ignited fuel. Accidental fire induces different heat flux conditions within the energetic device depending upon the severity, proximity, and duration of the fire.

Using the example of a thermal insult, there is a strong correlation between heat flux and what is commonly referred to as time-to-explosion of the energetic or explosive material. The magnitude of the heat flux influenced by the duration the energetic device is subjected to the thermal source, the temperature of the thermal source, and environmental conditions will often dictate the energetic material's time-to-explosion, as well as the amount of energetic material ignited. Notably, this relationship between time-to-explosion and heat flux largely determines the resulting severity or intensity of the explosion, or more commonly the violence of the explosion, in response to the insult on the energetic material.

Being somewhat unintuitive, it has been discovered that an insult induced explosion is relatively less violent when the energetic material is subjected to a rapid rate of external heat flux, such as when the energetic device is engulfed in flames. A rapid rate of heat flux causes a relatively less violent explosion because of the non-uniform heating of the energetic material as a whole. In other words, portions of the energetic material, particularly the inner portions, are not permitted to reach the ignition temperature, and thus do not ignite. Indeed, only the outer or surface layers of the energetic material rise to the ignition temperature, and thus ignite. This partial ignition, in which only the outer portions of the energetic material is ignited, results in a much less violent explosion as less explosive power, and therefore less energy, is released.

Conversely, an insult induced explosion is relatively more violent when the energetic material is subjected to a slow rate of external heat flux, such as when the energetic device is exposed for a prolonged period of time to a thermal source (e.g., when the energetic device is partially engulfed in flames or adjacent to or in close proximity to flames). A slow rate of heat flux produces a more violent explosion because the energetic material, as a whole, is more uniformly heated. In other words, most, if not all, of the energetic material is permitted to reach the ignition temperature, and thus ignite. Because all of the energetic material ignites simultaneously, more explosive power, and therefore more energy, is released, thus resulting in an explosion that is much more violent. As such, in the event of a mechanical or thermal insult, such as an accidental fire, it is desirable to protect the energetic device, and more particularly the energetic material contained therein, from prolonged exposure to a thermal source that provides a low level heat flux, which would increase the violence of the explosion. However, this is often not possible. As such, it may be desirable to take other measures to reduce the violence or intensity of the explosion.

As can be seen from the above discussion, any mechanical or thermal insult resulting in damage to the energetic material will result in a much more violent explosion than normal due to the fact that the effect of the insult is to increase the explosive surface area of the energetic material.

Based on the foregoing, there is an apparent need for various methods and systems specifically designed to reduce the reaction violence or reaction intensity of an energetic material during an accidental explosion caused by a mechanical or thermal insult.

SUMMARY OF THE INVENTION

In light of the problems and deficiencies inherent in prior related energetic devices, the present invention seeks to overcome these by rendering energetic devices, and more particularly the energetic material contained within the device, less susceptible to responses currently identified as violent. Stated differently, the present invention seeks to overcome the above-described deficiencies by reducing the relative violence or intensity resulting from an insult-induced or accidental explosion of an energetic device. In doing so, it may be possible to classify suitably equipped energetic devices under a less restrictive categorical division, which would effectively reduce the costs associated with the manufacture, transportation, storage, and deployment of the energetic device, and more importantly, the hazards associated with accidental explosions, such as danger to personnel and equipment.

In accordance with the invention as embodied and broadly described herein, the present invention features a method for reducing the violence of an accidental explosive reaction of an energetic material, the method comprising: (a) obtaining a solid energetic material configured for use within an energetic device, the energetic material comprising at least one void formed therein; and (b) supplying, filling, or otherwise applying at least a portion of the at least one void with an inert, substantially incompressible material configured to mechanically stabilize the energetic material to prevent the void from collapsing and the surface area of the energetic material from increasing in the event of an insult tending to damage the energetic the material. It is preferred that the inert, incompressible material conform to the void or other geometric configuration.

In one exemplary embodiment, the inert, incompressible material is configured to temporarily modify the energetic device, meaning that the inert, incompressible material is configured to be removably inserted or otherwise applied to the energetic device. In one aspect, the inert, substantially incompressible material may be configured for repeated insertion into and removal from the energetic material. The inert, incompressible material may be inserted or applied to the energetic material prior to transporting, handling or storing, and removed prior to an intended function of the energetic device.

The present invention further features a method for facilitating a reduction in violence of an accidental explosive reaction of an energetic material, the method comprising: (a) providing an inert, substantially incompressible material configured and intended for insertion into a void of an energetic material, the inert, incompressible material being configured to mechanically stabilize the energetic material to prevent the void from collapsing and the surface area of the energetic material from increasing in the event of an insult tending to damage the energetic material; and (b) facilitating the application of the inert, incompressible material to the energetic material.

The present invention still further features an energetic material configured for use within an energetic device, the energetic material comprising: (a) a substantially solid body configuration having at least one void formed therein; and (b) an inert, substantially incompressible material removably disposed within at least a portion of the void, the inert, incompressible material being configured to mechanically stabilize the energetic material to prevent the void from collapsing and the surface area of the energetic material from increasing in the event of an insult tending to damage the energetic the material, the inert, incompressible material reducing the violence of an accidental explosive reaction of the energetic material.

The present invention still further features an energetic device comprising: (a) a support structure; (b) a solid energetic material supported within the support structure and configured to ignite and burn to provide energy and power to the energetic device, the solid energetic material comprising at least one void formed therein; and (c) an inert, substantially incompressible material removably disposed within at least a portion of the void, the inert, incompressible material being configured to mechanically stabilize the energetic material to prevent the void from collapsing and the surface area of the energetic material from increasing in the event of an insult tending to damage the energetic the material.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings merely depict exemplary embodiments of the present invention they are, therefore, not to be considered limiting of its scope. It will be readily appreciated that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Nonetheless, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 illustrates a cross-sectional view representing a support structure of a prior related energetic device, wherein the support structure comprises an energetic material supported therein, and wherein the energetic material comprises a void formed therein in the form of a central core; and

FIG. 2 illustrates a cross-sectional view of the represented support structure of the energetic device of FIG. 1, wherein the energetic material comprises an inert, incompressible material supported within its central core;

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following detailed description of exemplary embodiments of the invention makes reference to the accompanying drawings, which form a part hereof and in which are shown, by way of illustration, exemplary embodiments in which the invention may be practiced. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. Thus, the following more detailed description of the embodiments of the present invention, as represented in FIGS. 1 through 2, is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the present invention, to set forth the best mode of operation of the invention, and to sufficiently enable one skilled in the art to practice the invention. Accordingly, the scope of the present invention is to be defined solely by the appended claims.

The following detailed description and exemplary embodiments of the invention will be best understood by reference to the accompanying drawings, wherein the elements and features of the invention are designated by numerals throughout.

The present invention describes a method and system for reducing the violence or intensity of inadvertent or accidental explosions, such as those caused by mechanical or thermal insult, of energetic material. More specifically, the present invention describes a method and system for reducing such violence by filling one or more voids formed in an energetic material with an inert, incompressible material. The inert, incompressible material may be provided or otherwise disposed to fill partially or completely each of the one or more voids of the energetic material. In addition, the inert, incompressible material may be supplied to or otherwise configured to function with one or more geometric configurations formed or located on the energetic material.

The present invention provides several significant advantages over prior related energetic devices and methods, some of which are recited here and throughout the following more detailed description. Indeed, the presence of an inert, incompressible material within the one or more voids of an energetic material provides many advantages. First, and foremost, the violence of any inadvertent insult-induced explosion is reduced. This reduction in violence may be significant enough to possibly qualify the energetic material to be classified in another, less restrictive explosive division, wherein all of the attendant advantages resulting from classification in a less restrictive division shall also inure to the benefit of those manufacturing, handling, and/or storing the energetic material or the energetic devices containing such. In the case of tactical missiles, the additional margins of safety would also benefit military operations by making it easier, faster and safer to deploy larger numbers of weapons in smaller magazines. This is of particular importance in naval operations where space is extremely limited. Second, the inert, incompressible material functions to stabilize the energetic material so that much of it remains unreacted in the event of an inadvertent explosion. Indeed, a less violent explosion typically means that only a fraction of the energetic material was consumed and that there was a low level of fragmentation. This is true since it is well known in the art that the creation of small fragments is indicative of an exhaustive explosion. Third, the inert, incompressible material may be designed to be temporarily inserted or otherwise secured within the void of an energetic material.

Each of the above-recited advantages will be apparent in light of the detailed description set forth below, with reference to the accompanying drawings. These advantages are not meant to be limiting in any way. Indeed, one skilled in the art will appreciate that other advantages may be realized, other than those specifically recited herein, upon practicing the present invention.

Preliminarily, it is noted that the term “void,” as referred to herein, shall be understood to mean any space, hole, cavity, core, crack, crevice, opening, fissure, hollow, or other similar area devoid of energetic material.

In addition, the phrase “geometric configuration,” as referred to herein, shall be understood to mean any fin, protrusion, crack, slit, void, cutout, or any other simple or complex geometry formed within or about the one or more voids formed in the energetic material.

The phrase “energetic material,” as referred to herein, shall be understood to mean any solid material having an explosively reactive property. For example, the energetic material may be selected from those consisting of a propellant, a pyrotechnic, an explosive, and other similar materials.

The phrase “energetic device,” as referred to herein, shall be understood to mean any type of device, system, or assembly comprising or supporting an energetic material.

The term “insult,” as referred to herein, shall be understood to mean any mechanical or thermal disturbance having the propensity to mechanically or structurally damage the energetic material, thereby increasing its surface area.

The phrase “inert, substantially incompressible material,” as referred to herein, shall be understood to mean any type of non-reactive solid, a liquid, or semi-liquid material that comprises an incompressible or substantially incompressible property as commonly known in the art.

With reference now to FIG. 1, illustrated is a cross-sectional representation of a prior related energetic device. As shown, the represented energetic device 10 comprises a general support structure 14 in the form of a cylindrical casing. In one exemplary embodiment, the energetic device 10 may comprise a solid fuel rocket motor, and corresponding support structure 14 may comprise that found in a solid fuel rocket motor, in which the support structure 14 would comprise a motor casing configured to form the exterior of the rocket motor and provide the necessary structural integrity and support for the rocket motor. Because of its designed purpose and function, the support structure 14 is typically made from a rigid and durable material, such as steel or even a type of composite, such as a filament wound composite. Although the exemplary embodiment refers to a solid fuel rocket motor, the energetic device 10 may comprise other types that are known in the art.

The support structure 14 or cylindrical casing of the energetic device 10 is configured to support an energetic material 18 therein. The energetic material 18 primarily functions to explosively react under controlled conditions for an intended purpose, such as to provide power from a solid fuel rocket motor, which provides the thrust for the rocket. As such, the reactive phases are largely contained within the support structure 14. For example, the propellant in a solid fuel rocket motor is burned within the interior of the rocket motor case, thus forming high pressure gasses. The rocket motor case is configured with a throat or nozzle, through which the high pressure gasses are allowed to release to propel the rocket.

The energetic material 18 may comprise various types, each of which include one or more reactive constituents. In one embodiment, the energetic material 18 may comprise a propellant, such as a solid propellant. In another embodiment, the energetic material 18 may comprise a pyrotechnic. In still another exemplary embodiment, the energetic material 18 may comprise an explosive. In the exemplary embodiment of a solid fuel rocket motor, the solid fuel comprises a molded propellant.

The energetic material 18 also preferably comprises a solid body configuration, wherein the energetic material 18 may be configured with one or more voids formed therein as known in the art. In the embodiment shown, the energetic material 18 comprises a void 22 in the form of a central core. Forming one or more voids in the energetic material 18 functions to increase its surface area, therefore, increasing its burn rate when ignited for one or more intended purposes. The energetic material 18 may comprise a plurality of voids, depending upon design and other factors. These may be located along the outer periphery or surface of the energetic material 18, or they may be located within the energetic material 18, such as the central bore shown in FIG. 1.

The energetic material 18 may further comprise one or more geometric configurations, as commonly known in the art, to enhance the burn rate of the energetic material 18. These may comprise configurations such as fins, vanes, etc.

With reference to FIG. 2, illustrated is a cross-sectional view of the energetic device 10 represented in FIG. 1. However, as shown, the energetic device 10 comprises an inert, substantially incompressible material 30 disposed, filled, or otherwise supported within the void 22 (the central core). The inert, incompressible material 30 is configured to conform to the void 22. In addition, the inert, incompressible material 30 is designed to support and stabilize the void 22 and other portions of the energetic material, such as any geometric configurations, in the event of an insult on the energetic device 10 and the energetic material 18 contained therein. More specifically, the inert, incompressible material 30 functions to prevent the void 22 from collapsing and the surface area from increasing, which increase in surface area results in a much more violent or intense explosion than if the energetic material 18 was not damaged. As explained above, a thermal or mechanical insult to the energetic device may mechanically or structurally damage the energetic material. For example, a thermal insult may cause significant internal localized pressures within the energetic material resulting in fragmentation of a portion of the energetic material, thus increasing the surface area of the energetic material, and therefore the reactive violence in the event of an accidental or inadvertent explosion. Likewise, a mechanical insult, such as an impact to the energetic device, may crack or fracture the energetic material, also increasing its surface area. To prevent the undesirable increase in surface area in, or rather to reduce the likelihood of mechanical or structural damage to, the energetic material 18, the inert, incompressible material 30 is inserted into all or a portion of the void 22, wherein it functions to render the energetic device less susceptible to violent explosion by resisting the forces acting within the energetic material in the event of an insult. The inert, incompressible material stabilizes the void and the energetic material as a whole. Of course, an inert, incompressible material may be inserted into other voids formed within the energetic material. Moreover, it is further contemplated that an inert, incompressible material may be applied or supplied to any one of the geometric configurations existing within or on the energetic material. In essence, the inert, incompressible material is configured to be inserted into or between the one or more voids and/or geometric configurations of the energetic material to fill volumetric voids left by these.

The inert, incompressible material 30 is preferably configured to be removable from the one or more elements (e.g., voids, geometric configurations) of the energetic material 18. As indicated above, the energetic material 18 is designed to perform a specific and intended explosive function. Therefore, under controlled conditions, the energetic material will be ignited or reacted for this purpose. At such time, the inert, incompressible material 30 may be removed as the energetic device is not likely to be in danger of an insult or disturbance. Although the application of an inert, incompressible material may be temporary in nature, the likelihood of reducing the violence or intensity of a potential accidental explosive response to a thermal or mechanical insult or disturbance will most likely have a significant impact on the costs of transporting and storing of energetic devices. Indeed, the modification to the energetic device, as taught and suggested herein, may be made prior to and remain in place during the transportation and storage of the energetic device, and then removed at a time of intended ignition.

The present invention further features a container 38 configured to house or support the inert, incompressible material 30. The container 38 functions to provide an efficient vehicle for inserting and removing the inert, incompressible material 30 from the one or more voids, such as void 22. When inserted, the container 38 provides a barrier between the energetic material 18 and the inert, incompressible material 30 that performs various functions, one of which is to reduce the chance of adverse reactions. In one exemplary embodiment, as shown in FIG. 2, the container 38 comprises an inert bladder. In another exemplary embodiment, the container 38 may comprise a moldable structure that is also inert. In addition, the container 38 is preferably comprised of materials having a low vapor pressure so that when the container is subjected to low level heating, the heat would not generate gasses inside the energetic device, which may generate pressure and possibly accelerate an explosion.

As indicated, the container 38 is preferably made of one or more inert materials, wherein the container is compatible with the particular energetic material present within the energetic device. In other words, the material(s) of the container may largely depend on the particular type and makeup of energetic material being used in the energetic device. The container may further comprise multiple liners. Still further, the present invention may comprise a sensor, such as a moisture sensor, supported within or about the container that is operable to detect and signal any defects or breaches in the container. The container may be configured to be malleable so that it better conforms to the voids and/or geometric configurations of the energetic material.

Effective inert, substantially incompressible materials may be in any form, such as a solid, a liquid, or a semi-liquid, namely a gel. These may be configured for use in the liquid state at high temperatures. Examples of some of the contemplated inert, incompressible materials include, but are not limited to, water, sand, ceramic particulates, various sealants, gels, and others that are incompressible or substantially incompressible. In consideration of the practical applications of the present invention in field deployment of the energetic devices, one advantageous material may be a liquid or a gel that is both easy to insert either at the time of manufacture of the energetic device or just prior to its transportation and/or storage, and easy to remove prior to an intended ignition and deployment of the energetic device. A liquid or gel is more likely to conform to any voids and/or geometric configurations than a solid, although a solid may be configured with precise dimensions. In one exemplary embodiment, the most advantageous fluid may be water. Using water would avoid problems of disposal, toxicity, or handling. At a time of insertion, a container may be filled with water. Similarly, at a time of removal, the water could simply be emptied from the container. Although water has a higher vapor pressure than other fluids, it is anticipated that the container of water will not heat as quickly as the external support structure and outer surface of the energetic material in the event of an accidental fire.

Some of the primary things to consider when selecting an appropriate inert, incompressible material include its ease of removal, whether or not the material might pose a hazardous threat to personnel at the point of insertion or removal, and its ability to be easily and properly disposed of or recycled.

The following examples set forth and present the effects of an inert, incompressible material as applied to or inserted within one or more voids or geometric configurations of an energetic material. These examples are not to be construed as limiting in any way, but are merely presented to illustrate the beneficial, advantageous, and reducing effects of an inert, incompressible material on the violence of an accidental explosive reaction caused by a thermal insult.

EXAMPLE ONE

Various tests or experiments were conducted to observe the behavior and response of several energetic devices as they were subjected to a thermal insult. The purpose of the tests was to determine the time-to-explosion and the degree of violence or intensity of the explosive response of the energetic devices in response to different levels of external heat flux. The tests also showed the results of utilizing an inert, incompressible material as taught and suggested herein. The experiments were carried out using a four-inch diameter cylindrical steel support structure filled with PBX-9501 propellant as the energetic material. The PBX-9501 propellant was heated electrically with electrical heating mantels. Voltages between 110 and 220 volts were supplied to the energetic device for a duration of time between 1 and 30 minutes. For the various tests, a molded high energy PBX-9501 propellant was used and configured as follows:

1) Test One—the core of a PBX-9501 material was hollowed out and rapid heating was applied to the energetic device.

2) Test Two—the core of a PBX-9501 material was hollowed out and slow heating was applied to the energetic device.

3) Test Three—a PBX-9501 was configured to comprise a solid core and slow heating was applied to the energetic device.

4) Test Four—the core of a PBX-9501 material was hollowed out and then filled with an inert, incompressible material. Slow heating was applied to the energetic device.

The results of the several experiments are identified below in Table One.

TABLE ONE
Configuration		Status of	Status of
of PBX-9501	Observed Time-	the Support	the PBX-9501
Propellant	to-Explosion	Structure	Propellant
Test One -	3	minutes	ruptured	most propellant
hollow core			and burning	is recovered
rapid heating				unburned and
				core collapsed
Test Two -	25	minutes	violent rupture,	complete
hollow core &			small fragments	consumption of
slow heating			propelled with	propellant and
			velocities	core collapsed
			of >1200 ft/s
Test Three -	27	minutes	ruptured	partial burnt
solid core &				propellant
slow heating
Test Four -	23	minutes	ruptured	partial burnt
core w/inert				propellant,
material &				core intact
slow heating

As can see from Table One, the PBX-9501 propellant having its inner core filled with an inert, incompressible material was rendered more stable and less susceptible to mechanical and thermal disturbances resulting in much less violent or intense explosive reactions.

During this testing, it was observed that the difference in the violence or intensity of the explosions of those energetic devices not employing an inert, incompressible material as compared to the explosions of those comprising such a material was significant. Indeed, the results were significant enough to most likely justify a reclassification of the response of an energetic device from a Division 1.2 or 1.3 response to a Division 1.1 or 1.2 response if such an inert, incompressible material were to be employed within the energetic device.

EXAMPLE TWO

A high-temperature inert, incompressible sealant was injected into the central bore hole of a steel container filled with a PBX 9501 propellant and fitted with a 110 volt electric heating band to fill the core. The sealant was allowed to set up overnight. Test was conducted in a similar manner as set forth above in Example One. The time-to-explosion was 23 minutes and the steel container did not fragment or burst open, but rather bulged. A large piece of unreacted material was recovered. This piece comprised a portion of the core with the sealant material still contained within the core. As such, the core had not collapsed. This test indicates that the inert, incompressible sealant inserted into the central bore hole or core stabilized the core such that it did not collapse, thus largely preserving the structural integrity of the steel container. In addition, much of the PBX-9501 material was not consumed, but left intact. By preventing the core from collapsing, the resulting explosive response appears to have been much less violent.

The foregoing detailed description describes the invention with reference to specific exemplary embodiments. However, it will be appreciated that various modifications and changes can be made without departing from the scope of the present invention as set forth in the appended claims. The detailed description and accompanying drawings are to be regarded as merely illustrative, rather than as restrictive, and all such modifications or changes, if any, are intended to fall within the scope of the present invention as described and set forth herein.

More specifically, while illustrative exemplary embodiments of the invention have been described herein, the present invention is not limited to these embodiments, but includes any and all embodiments having modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the foregoing detailed description. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the foregoing detailed description or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive where it is intended to mean “preferably, but not limited to.” Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. Means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are expressly recited. Accordingly, the scope of the invention should be determined solely by the appended claims and their legal equivalents, rather than by the descriptions and examples given above.

Claims

1. A method for reducing the violence of an accidental explosive reaction of an energetic material, said method comprising:

obtaining a solid energetic material configured for use within an energetic device, said energetic material comprising at least one void formed therein; and

supplying at least a portion of said at least one void with an inert, substantially incompressible material configured to mechanically stabilize said energetic material to prevent said void from collapsing and the surface area of said energetic material from increasing in the event of an insult tending to damage said energetic said material.

2. The method of claim 1, further comprising removing said inert, incompressible material prior to an intended ignition of said energetic material.

3. The method of claim 1, further comprising supporting said solid energetic material within an energetic device.

4. The method of claim 1, further comprising configuring said void of said energetic material with at least one geometric configuration configured to enhance a burn rate of said energetic material upon ignition.

5. The method of claim 4, further comprising supplying said at least one geometric configuration with an inert, incompressible material.

6. The method of claim 1, further comprising inserting said inert, incompressible material into said void of said energetic material prior to transporting, storing, and otherwise handling said energetic material.

7. The method of claim 1, further comprising supporting said inert, incompressible material within a container, wherein said container and said inert, incompressible material contained therein are configured to be removably inserted within said void.

8. The method of claim 1, further comprising securing, temporarily, said inert, incompressible material in place within said void.

9. A method for facilitating a reduction in violence of an accidental explosive reaction of an energetic material, said method comprising:

providing an inert, substantially incompressible material configured and intended for insertion into a void of an energetic material, said inert, incompressible material being configured to mechanically stabilize said energetic material to prevent said void from collapsing and the surface area of said energetic material from increasing in the event of an insult tending to damage said energetic material; and

facilitating the application of said inert, substantially incompressible material to said energetic material.

10. The method of claim 9, further comprising supporting said inert, incompressible material within a container.

11. An energetic material configured for use within an energetic device, said energetic material comprising:

a substantially solid body configuration having at least one void formed therein; and

an inert, substantially incompressible material removably disposed within at least a portion of said void, said inert, incompressible material being configured to mechanically stabilize said energetic material to prevent said void from collapsing and the surface area of said energetic material from increasing in the event of an insult tending to damage said energetic said material, said inert, incompressible material reducing the violence of an accidental explosive reaction of said energetic material.

12. The energetic material of claim 11, further comprising a container configured to support said inert, incompressible material and to facilitate the insertion and removal of said inert, incompressible material within said void of said energetic material, said container comprising a barrier for said inert, incompressible material.

13. The energetic material of claim 12, wherein said container comprises an inert material.

14. The energetic material of claim 12, wherein said container is formed of material(s) having a low vapor pressure.

15. The energetic material of claim 12, further comprising a sensor configured to detect and signal a breach in said container.

16. The energetic material of claim 11, wherein said inert, incompressible material is selected from the group consisting of a solid material, a liquid material, and a semi-liquid or gel material.

17. The energetic material of claim 11, wherein said energetic material is selected from the group consisting of a propellant, a pyrotechnic, and an explosive.

18. The energetic material of claim 11, wherein said void further comprises at least one geometric configuration operable therewith configured to enhance a burn rate of said energetic material upon ignition.

19. The energetic material of claim 18, wherein said inert, incompressible material is functional with said at least one geometric configuration to prevent said void from collapsing.

20. The energetic material of claim 11, wherein said void comprises a central core formed in said solid body.

21. The energetic material of claim 11, wherein said inert, incompressible material conforms to said void and any geometric configurations therein.

22. An energetic device comprising:

a support structure;

a solid energetic material supported within said support structure and configured to ignite and bum to provide energy and power to said energetic device, said solid energetic material comprising at least one void formed therein; and

an inert, substantially incompressible material removably disposed within at least a portion of said void, said inert, incompressible material being configured to mechanically stabilize said energetic material to prevent said void from collapsing and the surface area of said energetic material from increasing in the event of an insult tending to damage said energetic said material.

23. The energetic device of claim 22, wherein said energetic device comprises a solid fuel rocket motor.