Propulsion Device Regulated Gas Flow for ALR

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Solution Overview

Problem

Existing large-caliber projectile propulsion devices are not suitable for ALR applications due to uncontrolled unburned propellant powder, leading to inconsistent exit velocities and potential jamming or degradation of the device, as they require a reduced quantity of propellant powder which results in insufficient confinement and combustion inefficiencies.

Innovation Solution

A cartridge design featuring a rear chamber with igniting means and confinement vents, an intermediate chamber of constant volume, and a low-pressure chamber with a regulated orifice for controlled gas flow, ensuring complete combustion and progressive pressure increase for safe and controlled ejection of large-caliber projectiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a reduced quantity of propellant powder is used to achieve low exit velocity for ALR applications, then the projectile exit speed is reduced to compatible levels, but the combustion becomes incomplete and unburned powder remains in the chamber

Engineering Contradiction:
Improveprojectile exit velocityVSAvoidcombustion completeness
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The combustion chamber is divided into a first chamber for propellant combustion and a second chamber for projectile propulsion, separated by a diaphragm. This segmentation allows the first chamber to maintain high pressure and temperature for complete combustion of reduced powder quantities, while the second chamber receives controlled gas flow to propel the projectile at reduced velocity without requiring excessive powder that would cause incomplete combustion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A diaphragm acts as an intermediary element between the first combustion chamber and the second propulsion chamber. It transmits pressure from the combustion gases to propel the projectile while maintaining separate combustion conditions in each chamber, ensuring complete burning of the propellant before gas expansion occurs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Force

If a large quantity of propellant powder is used to ensure safe propulsion of large-caliber projectiles, then the propulsion force is sufficient, but the exit velocity becomes too high for ALR applications and unburned powder increases

Engineering Contradiction:
Improvepropulsion forceVSAvoidprojectile exit velocity
Core Design Contradiction:
ForceVSSpeed

Solution Approach 1:

The propulsion system is segmented into two chambers: the first chamber generates high propulsion force through complete combustion of a controlled powder quantity, while the second chamber allows gradual gas expansion to propel the projectile. This segmentation enables sufficient force generation without excessive exit velocity or unburned powder.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the pressure parameter through controlled gas flow regulation. The first chamber maintains high pressure for complete combustion and force generation, while the second chamber allows pressure to decrease gradually as the projectile moves along the barrel, achieving both sufficient propulsion force and controlled exit velocity.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the volume of the combustion chamber is increased to accommodate large-caliber projectiles, then the projectile can be propelled, but the risk of unburned powder increases due to insufficient confinement

Engineering Contradiction:
Improvecombustion chamber volumeVSAvoidcombustion efficiency
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The large-volume combustion chamber is segmented into a first chamber with restricted volume for propellant combustion and a second chamber for projectile propulsion. The diaphragm separates these functions, ensuring that the combustion phase occurs in a confined space that maintains high pressure and temperature for complete burning, while the larger second chamber volume allows controlled gas expansion without compromising combustion efficiency.

Inventive Principle:
Principle #1Segmentation

4Speed

If the quantity of propellant powder is reduced for ALR applications, then the exit velocity is reduced to acceptable levels, but the projectile may jam or progress jerkily in the barrel due to insufficient thrust

Engineering Contradiction:
Improveprojectile exit velocityVSAvoidpropulsion smoothness
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The system ensures continuous useful action by maintaining pressure in the second chamber throughout the projectile's travel along the barrel. The regulated gas flow from the first to the second chamber provides continuous thrust, preventing the projectile from stopping or progressing jerkily, while still achieving reduced exit velocity suitable for ALR applications.

Inventive Principle:
Principle #20Continuity of useful action

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 solution ensures complete combustion of propellant powder, reducing the risk of unburned matter and pressure peaks, allowing for controlled and safe ejection of large-caliber projectiles at low speeds, preventing jamming and ensuring consistent performance.

Implementation Method 1

an ignition system aimed at igniting a propellant powder placed in a combustion chamber, the pressure thus generated in the combustion chamber causing the propulsion of the projectile

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

means for confining the powder in the rear chamber while allowing the gases resulting from the combustion of the powder to pass through vents in the rear chamber

Methodology Applied
Scientific EffectPhysical confinement: Physical Containment

Implementation Method 3

a low pressure chamber, forming the projectile propulsion chamber, and communicating with the intermediate chamber through an orifice of predetermined section

Methodology Applied
Scientific EffectFluid flow regulation:

Data Source

PatentEP2192376B1Propulsion device with regulated engagement
Publication Date: 2015.04.22 NEXTER MUNITIONS SA
  • EP2192376B1 patent drawingFigure 1~2

AI summary

The cartridge has a rear chamber (1) including an ignition unit. A confining unit confines a propelling powder i.e. progressive combustion powder, in the rear chamber, while allowing passage of gases resulting from combustion of the powder via vents of the rear chamber. A low pressure chamber (3) forms a projectile propulsion chamber, and is communicated with an intermediate chamber (2) having constant volume by an opening (13) of a predetermined section. A wedging disk is made of polystyrene, felt or carton, and placed around an igniting tube.