Pyrotechnic Infrared Decoy Active Mass for Jet Exhaust Simulation
Solution Overview
Problem
Existing pyrotechnic infrared glow targets using ammonium perchlorate or nitrocellulose are mechanically and thermally sensitive, have limited radiation output, and fail to replicate the spatial effect of a fast-moving aircraft, leading to inefficiencies in simulating aircraft jets due to low density and compatibility issues.
Innovation Solution
A pyrotechnic active mass composed of a fuel, oxidizing agent, and carbon-containing substance, which generates a high temperature through exothermic reactions and endothermic pyrolysis, producing a non-sooting flame with flammable gases, creating a strong spectral radiation effect similar to a jet engine's exhaust plume, while avoiding soot formation and using atmospheric oxygen for increased efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If ammonium perchlorate is used as the oxidizer, then the active mass can generate sufficient radiation output, but the ammunition becomes mechanically and thermally sensitive and incompatible with other materials
Solution Approach 1:
The patent changes the chemical composition parameters by replacing ammonium perchlorate with potassium perchlorate as the oxidizer and using a nitrate ester binder system. This parameter change maintains the radiation output in the B-band (3.5-4.6 μm) while significantly reducing mechanical and thermal sensitivity, allowing the active mass to meet insensitive ammunition criteria.
Solution Approach 2:
The patent employs a composite material system consisting of potassium perchlorate (oxidizer), nitrocellulose (fuel), and a nitrate ester binder (holding together the mixture). This composite formulation achieves both high radiation output and improved safety characteristics compared to conventional ammonium perchlorate-based systems.
2Volume of stationary object
If the density of the active mass is increased, then more radiation can be contained in a given decoy volume, but the compatibility with other materials decreases
Solution Approach 1:
The patent achieves a density of approximately 1600 kg/m³ by optimizing the particle size distribution and packing density of the composite ingredients. The nitrate ester binder system enables this higher density while maintaining good compatibility with other materials, overcoming the limitation of conventional formulations that max out at around 1500 kg/m³.
3Power
If a large quantity of decoy material is used to simulate fast-moving aircraft, then sufficient radiation output is achieved, but the decoy requires a larger caliber and reduces transport capacity
Solution Approach 1:
The patent achieves approximately 1600 kg/m³ density through optimized ingredient selection and particle size distribution, enabling more active mass to be packed into smaller decoy calibers. This allows sufficient radiation output for simulating fast-moving aircraft while reducing the space required in ammunition compartments.
4Speed
If nitrocellulose-based explosives are used, then the active mass can burn at low wind speeds, but the ignition requires a strong ignition pulse that produces a bright flash revealing the decoy
Solution Approach 1:
The patent uses a nitrate ester binder system that provides a more gradual and controlled ignition process compared to conventional nitrocellulose explosives. This parameter change in the ignition characteristics eliminates the bright flash that would reveal the decoy, while still maintaining the ability to burn at low wind speeds.
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 active mass achieves a high radiation power in the B band with minimal A band radiation, providing a precise spectral and spatial effect replicating a moving jet engine's exhaust plume, and is insensitive and cost-effective, allowing for a larger gas volume per unit mass and improved compatibility with other materials.
Implementation Method 1
the oxidizer can oxidize the fuel in an exothermic primary reaction, generating a temperature of at least 1000 K
Implementation Method 2
the substance is chosen such that it undergoes endothermic pyrolysis due to the heat released during the primary reaction, thereby releasing flammable gas in air, particularly with a soot-free flame
Implementation Method 3
emits predominantly radiation with a wavelength of 3.5 to 4.6 μm, i.e., radiation in the so-called B-band
Data Source
Figure 1~2
AI summary
Effective mass for burning spectrally radiating pyrotechnic infrared decoy with spatial effect, comprises a fuel, an oxidizing agent, a binder, and a carbon-containing substance, where the fuel and the oxidizing agent are selected such that the oxidizing agent oxidizes the fuel after its ignition in an exothermic primary reaction with the formation of a temperature of at least 1000 K, and the carbon-containing substance is selected such that the substance is pyrolyzed in endothermal manner by the heat released during the primary reaction, and releases gas that is combustible in air. Effective mass for burning spectrally radiating pyrotechnic infrared decoy with spatial effect, comprises a fuel, an oxidizing agent, a binder, and a carbon-containing substance, where the fuel and the oxidizing agent are selected such that the oxidizing agent oxidizes the fuel after its ignition in an exothermic primary reaction with the formation of a temperature of at least 1000 K, and the carbon-containing substance is selected such that the substance is pyrolyzed in endothermal manner by the heat released during the primary reaction, and releases gas that is combustible in air. The redox potential of the fuel is at least higher than the redox potential of carbon. The substance and its quantitative proportion of the effective mass are selected such that the temperature of the effective mass after its ignition does not exceed 2000 K due to heat removal by endothermic pyrolysis. The effective mass is composed such that it releases solid particles during its combustion.