Patterned Thermite Propellant for Controlled Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional propellants for firearms and other applications experience a rapid increase and subsequent decrease in gas pressure, leading to lost opportunities for increasing projectile velocity, as the pressure decreases while the projectile is still within the barrel.
Innovation Solution
A thin film propellant with a high burn rate material, such as thermite, is deposited in a pattern on a substrate sheet, allowing for a predetermined ignition rate and pressure curve by controlling the coverage area of the ignitable material, which is rolled around a nonburnable tube and inserted into a cartridge casing to maintain a consistent pressure level throughout the projectile's travel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional propellants are used, then the propellant burns quickly to produce gas pressure, but the pressure reaches maximum very quickly and then rapidly decreases, losing opportunity to increase projectile velocity
Solution Approach 1:
The propellant is divided into multiple granules with different size ranges (first granules: 0.5-2.0 mm, second granules: 2.0-4.0 mm, third granules: 4.0-8.0 mm) that burn at different rates, creating a segmented combustion process that extends pressure duration while maintaining velocity gain
Solution Approach 2:
The invention changes the burn rate parameter by using granules of different sizes - smaller granules burn faster while larger granules burn slower, creating a distribution of burn rates that maintains pressure over an extended period rather than a rapid spike and decline
2Productivity
If granule size is controlled to regulate burn rate, then the burn rate is controlled, but the pressure still reaches maximum quickly and decreases rapidly
Solution Approach 1:
Different regions of the propellant charge have different granule size distributions - the composition includes first granules (0.5-2.0 mm), second granules (2.0-4.0 mm), and third granules (4.0-8.0 mm) that create localized variations in burn rate throughout the charge, extending overall pressure duration
Solution Approach 2:
The propellant is a composite material combining three different granule size ranges in specific proportions (first granules: 30-70 wt%, second granules: 10-40 wt%, third granules: 5-20 wt%), creating a multi-component system with extended and controlled pressure duration
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
This approach maintains a consistent and controlled pressure level, allowing for higher projectile velocities while reducing felt recoil and wear on the firearm, by gradually increasing and maintaining pressure to optimal levels.
Implementation Method 1
Propellants typically burn to produce a gas. Increasing gas pressure serves to propel the projectile.
Implementation Method 2
A thermite reaction occurs between a metal oxide and a reducing metal.
Implementation Method 3
The ignitable material is deposited in a pattern, with the pattern defining at least one covered sheet portion upon which ignitable material has been deposited and at least one uncovered sheet portion upon which ignitable material is not present.
Data Source
AI summary
A propellant is made from a flexible sheet that in some examples is nitrocellulose. An ignitable material is deposited on one side of the flexible sheet. The ignitable material is a series of triangles having a base adjacent to one edge of the sheet, and an apex adjacent to the other side of the sheet. Some examples of the ignitable material may be thermite compositions. The flexible sheet is rolled around a nonburnable tube and placed within a firearm casing, with the triangle bases being adjacent to the back of the casing, and the triangle apexes being adjacent to the front of the casing. The nonburnable tube is disposed over the primer pocket, so that ignition products from the primer travel through the tube, igniting the propellant adjacent to the front of the casing.