Reactive Material Liner Velocity Enhancement in Explosively Formed Projectiles
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Solution Overview
Problem
Conventional explosively formed projectiles (EFPs) face limitations in destructive capability due to the geometry and weight of the projectile formed, as well as aerodynamic drag, which reduces velocity and effectiveness against heavily armored targets.
Innovation Solution
Incorporating a reactive material liner that ignites upon expulsion, increasing the velocity of the projectile beyond what is achieved by the explosive material, through a combination of fuels, oxidizers, and ignition initiators, which enhances the kinetic energy and aerodynamic stability of the projectile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional explosive material is used to form the projectile, then the projectile achieves sufficient initial velocity, but aerodynamic drag reduces velocity and limits destructive capability against heavily armored targets
Solution Approach 1:
The patent changes the chemical composition and energy release parameters of the liner material from conventional explosive to reactive material. The reactive material contains fuel, oxidizer, and ignition initiator in specific proportions, enabling controlled combustion that releases energy over an extended period, thereby maintaining higher velocity despite aerodynamic drag
Solution Approach 2:
The reactive material is pre-configured with ignition initiators distributed throughout its structure. Upon ejection, the ignition system activates the reactive material before the projectile encounters significant aerodynamic resistance, ensuring velocity enhancement occurs at the critical early phase of flight when drag begins to act on the projectile
2Strength
If the liner geometry and weight are increased to improve destructive capability, then penetration ability increases, but the velocity imparted by the explosive material decreases due to greater mass
Solution Approach 1:
The patent merges two energy delivery mechanisms: the initial impulsive energy from the explosive material that forms and ejects the projectile, and the sustained energy release from the reactive material that propels the already-formed projectile. This combination allows the liner to achieve both high initial velocity (for range) and sustained thrust (for penetration), resolving the trade-off between speed and strength
Solution Approach 2:
The reactive material provides continuous useful action through sustained combustion after ejection. While the explosive material provides only instantaneous energy release at detonation, the reactive material continues to burn and generate thrust throughout the projectile's flight, maintaining velocity and enhancing penetration capability without requiring increased liner mass
3Strength
If pyrophoric metals are added to the liner for incendiary effects, then secondary reactions improve destructive capability, but the liner's structural integrity and velocity generation may be compromised
Solution Approach 1:
The patent applies local quality by distributing ignition initiators and fuel-oxidizer components throughout the liner structure rather than concentrating pyrophoric metals in a separate layer. This ensures that incendiary effects are generated locally at multiple points along the projectile's flight path, maintaining structural integrity while providing sustained velocity enhancement and destructive capability
Solution Approach 2:
The reactive material liner is a composite material combining fuel, oxidizer, binder, and ignition initiator in a unified structure. This composite approach integrates the velocity-generation function (through controlled combustion) and the incendiary function (through pyrophoric reactions) into a single material system, eliminating the need for separate pyrophoric metal layers that would compromise structural integrity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The reactive material liner increases the projectile's velocity by 10-40% post-expulsion, enhancing its range and destructive capability, including penetration and behind-armor debris effects, while maintaining structural integrity.
Implementation Method 1
a reactive material liner that ignites upon expulsion, increasing the velocity of the projectile beyond what is achieved by the explosive material, through a combination of fuels, oxidizers, and ignition initiators
Implementation Method 2
utilize explosive energy to deform a liner disposed over a concave-shaped explosive material into a coherent projectile while simultaneously accelerating it to extremely high velocities
Data Source
AI summary
A liner assembly for an explosively formed projectile device may include a reactive material liner and a primary liner configured to form into a projectile responsive to initiation of an explosive material. The reactive material liner may be configured and formulated to increase the velocity of the projectile after formation thereof. An ordnance device for generating an explosively formed projectile may include a case, an explosive material, and a reactive material liner and a primary liner configured, in combination, to form into a projectile. An explosively formed projectile may include a deformed primary liner and a deformed reactive material liner having an ignited portion increasing the velocity of the projectile. Methods of explosively forming a projectile may include explosively expelling a primary liner and a secondary liner and increasing the velocity of the projectile by combusting at least a portion of the secondary liner.