EFFECT OF BORON ON THE COMBUSTION CHARACTERISTICS OF METALLIZED HIGH-ENERGY MATERIALS

2020 ◽  
Author(s):  
A. Korotkikh ◽  
◽  
I. Sorokin ◽  
◽  
Keyword(s):  
Specific Impulse ◽  
Equilibrium Composition ◽  
Combustion Products ◽  
High Energy ◽  
Combustion Characteristics ◽  
Solid Propellants ◽  
Energy Materials ◽  
High Energy Materials ◽  
Condensed Combustion Products ◽  
Active Fuel Binder

The paper presents the results of thermodynamic calculations of the effect of pure boron additives on combustion characteristics of high-energy materials (HEM) based on ammonium perchlorate, ammonium nitrate, active fuel-binder, and powders of aluminum Al, titanium Ti, magnesium Mg, and boron B. The combustion parameters and the equilibrium composition of condensed combustion products (CCPs) of HEM model compositions were obtained with thermodynamic calculation program “Terra.” The compositions of solid propellants with different ratios of metals (Al/B, Ti/B, Mg/B, and Al/Mg/B) were considered. The combustion temperature Tad in a combustion chamber, the vacuum specific impulse J at the nozzle exit, and the mass fraction ma of the CCPs for HEMs were determined.

THE BURNING RATE OF HIGH-ENERGY MATERIALS CONTAINING METAL FUELS BASED ON AL AND B

2020 ◽  
Author(s):  
A. Korotkikh ◽  
◽  
I. Sorokin ◽  
E. Selikhova ◽  
V. Arkhipov ◽  
...  
Keyword(s):  
Ammonium Nitrate ◽  
Specific Energy ◽  
High Energy ◽  
Solid Propellants ◽  
Amorphous Boron ◽  
Energy Materials ◽  
Energy Characteristics ◽  
High Energy Materials ◽  
Metal Borides ◽  
Active Fuel Binder

An effective method of increasing the energy characteristics of high-energy materials (HEMs) is the use of boron and metal borides powders, which have high values of specific energy released during oxidation and combustion. This study investigates powders of amorphous boron and aluminum borides, which are used in compositions of solid propellants based on ammonium perchlorate, ammonium nitrate, and active fuel-binder.

IGNITION, COMBUSTION, AND AGGLOMERATION OF HIGH-ENERGY MATERIALS BASED ON ALUMINUM AND BORON

2020 ◽  
Author(s):  
A. G. Korotkikh ◽  
◽  
V. A. Arkhipov ◽  
O. G. Glotov ◽  
I. V. Sorokin ◽  
...  
Keyword(s):  
Burning Rate ◽  
Ignition Time ◽  
Combustion Products ◽  
High Energy ◽  
Metal Powders ◽  
Energy Materials ◽  
Complete Replacement ◽  
Aluminum Powders ◽  
High Energy Materials ◽  
Condensed Combustion Products

The burning rate control of the high-energy materials (HEM) is mainly achieved by introducing the catalysts in composite solid propellant as well as by partial or complete replacement of ammonium perchlorate (AP) and ammonium nitrate by nitramines that change the equivalence ratio of formulation, or by varying the particle size of oxidizer and metal fuels. Promising metallic fuels are highly dispersed aluminum powders, which are characterized by different dispersity and passivation method, as well as bimetallic powders or mixtures of aluminum and other metals, their alloys, and metal powders with various coatings. In this study, the Al-based, Al/B-based, and Al/Fe-based HEM compositions have been used for comparative analysis of the ignition, combustion, and agglomeration characteristics. At the use of boron additive in the Al-based HEM, the ignition time is decreased by a factor of 1.2-1.4 and the burning rate is virtually unchanged as compared with that for the Al-based HEM. However, the agglomeration is significantly enhanced, which is manifested in the increase in the agglomerate particle content in condensed combustion products (CCP), increase in the agglomerate mean diameter, and increase in the unburned metal fraction in agglomerates.

scholarly journals Exploratory investigations on metal-based fuels for air-breathing propulsion

2019 ◽  
Author(s):  
F. Maggi ◽  
S. Colciago ◽  
C. Paravan ◽  
S. Dossi ◽  
L. Galfetti
Keyword(s):  
Specific Impulse ◽  
Combustion Products ◽  
High Energy ◽  
High Energy Density ◽  
Metal Powders ◽  
Air Breathing ◽  
Condensed Combustion Products ◽  
Calorimetric Investigations ◽  
Combustion Tests ◽  
Ducted Rocket

Air-breathing solid fueled propulsion devices represent rugged, cheap, and rather simple options, out of the ramjet (RJ) category, which can contribute to volume containment and structural weight reduction. In the case of a ducted rocket, a fuel-rich propellant is burned in a primary combustion chamber and part of the oxidizer is taken from the atmosphere to complete the combustion inside a ram burner before exhaust. The use of metal additives contributes to the development of high-energy density materials, featuring better volumetric specific impulse. Metal powders are characterized by high energetic content per unit volume but can feature issues of difficult ignition, generation of condensed combustion products (CCPs), and incomplete combustion. The present work discusses a series of exploratory investigations on aluminum-based pyrolants. Thermochemical analyses, calorimetric investigations, and combustion tests will be considered, looking at improvements introduced by metal addition.

THERMAL BEHAVIOR AND IGNITION OF HIGH-ENERGY MATERIALS CONTAINING B, ALB2, AND TIB2

2020 ◽  
Author(s):  
A. G. Korotkikh ◽  
◽  
V. A. Arkhipov ◽  
I. V. Sorokin ◽  
E. A. Selikhova ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Behavior ◽  
Flux Density ◽  
Ignition Delay ◽  
Delay Time ◽  
Heat Flux Density ◽  
Ignition Delay Time ◽  
High Energy ◽  
Energy Materials ◽  
High Energy Materials

The paper presents the results of ignition and thermal behavior for samples of high-energy materials (HEM) based on ammonium perchlorate (AP) and ammonium nitrate (AN), active binder and powders of Al, B, AlB2, and TiB2. A CO2 laser with a heat flux density range of 90-200 W/cm2 was used for studies of ignition. The activation energy and characteristics of ignition for the HEM samples were determined. Also, the ignition delay time and the surface temperature of the reaction layer during the heating and ignition for the HEM samples were determined. It was found that the complete replacement of micron-sized aluminum powder by amorphous boron in a HEM sample leads to a considerable decrease in the ignition delay time by a factor of 2.2-2.8 at the same heat flux density due to high chemical activity and the difference in the oxidation mechanisms of boron particles. The use of aluminum diboride in a HEM sample allows one to reduce the ignition delay time of a HEM sample by a factor of 1.7-2.2. The quasi-stationary ignition temperature is the same for the AlB2-based and AlB12-based HEM samples.

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