S. S. Bondarchuk

Influence of aluminum particle size on ignition and nonstationary combustion of heterogeneous condensed systems

The results of studies of the effect of particle size of aluminum powder in condensed systems on the ignition, nonstationary combustion, and acoustic conductivity of the burning surface are presented. Analysis of the experimental data shows that the ignition delay and the temperature of burning surface of the heterogeneous condensed systems under study decrease with increasing particle size of aluminum powder, and the nature of the dependence of the nonstationary burning rate on the time of depressurization of the combustion chamber for compositions containing micron or ultrafine aluminum powders is in qualitative agreement with the phenomenological theory of nonstationary combustion. Replacement of micron aluminum powder by ultrafine powder in a heterogeneous condensed system increases acoustic conductivity.

Investigation of combustion of HEM with aluminum nanopowders

A number of problems related to the utilization of nanosize aluminum powders as a combustible component of perspective compositions of high-energy materials is considered. The technology of producing nanopowders using the technique of conductor electrical explosion and the method of dispersed powder composition analysis are shown. The results of experimental studies of conductive and radiant ignition of model propellant compositions containing aluminum nanopowder, as well as the results of investigating the rate of stationary and non-stationary combustion of the given systems, are given. The results of an investigation of the ignition and combustion of ecologically safe propellant systems based on a dual oxidant (ammonium perchlorate and ammonium nitrate, which partially replaces it) containing aluminum nanopowder are demonstrated.

Remote Optical Diagnostics of Nonstationary Aerosol Media in a Wide Range of Particle Sizes

Polydisperse gas flows with condensed particles suspended therein are widely spread in nature and play an important role in many branches of the modern engineering and technology. There is a necessity for estimating parameters of disperse media in the manufacturing processes, scientific research, and atmosphere sounding. In industry, the result of this estimation can be employed as the quality measure of a product. When designing and distributing multi-phase systems to study the processes of controlling their parameters, it is also needed to determine values of the quantities characterizing such systems.

Novel Micro- and Nanofuels: Production, Characterization, and Applications for High-Energy Materials

In this paper, the problems of production and characterization of nanosized metals (nanosized aluminum) and microsized metal borides (including aluminum, titanium, magnesium) are discussed. The preferences of application for high-energy materials are presented. Also, the technique for production of nanometals is described which is the electric explosion wire method. The results of characterization of nanometals produced by that method are shown and discussed. To protect an active surface of nanoparticles, the different ways for passivation are suggested. Different polymers including Viton and Fluorel are suggested as passivated agents. The problems of chemical stability and chemical compatibility are discussed. A technique for production of metal borides is also described which is known as self-propagating high-temperature synthesis (SHS) and the subsequent mechanical treatment. The result is microsized borides which have an average size of around 5 μm with a sharp curve for distribution sizes. The purity is enough for use as fuel of high-energy materials. The results of TEM, SEM, X-ray, DSC, and TG analyses are also presented and discussed.

A Method for Laser Measurement of Disperse Composition and Concentration of Aerosol Particles

A modified method of small-angle scattering that consists in solving a series of direct problems in aerosol optics is proposed to obtain a function of particle size distibution; a modified method of spectral transperancy is employed to determine the concentration of particles in a cloud. A measurement system comprising radiator (helium-neon laser), photodetector and recording instruments has been developed. Measurements in aerosol clouds are performed.

Synthesis and Properties of Energetics Metal Borides for Hybrid Solid-Propellant Rocket Engines

In this paper, the problems of production and characterization of microsized metal borides (including aluminum, titanium, magnesium) are discussed. The preferences of application for high-energy materials are presented. The problems of chemical stability and chemical compatibility are discussed. A technique for production of metal borides is also described which is known as self-propagating high-temperature synthesis (SHS) and the subsequent mechanical treatment. The result is microsized borides which have an average size of around 5 microns with a sharp curve for distribution sizes. The purity is enough for use as fuel of high-energy materials hybrid solid-propellant rocket engines. The results of SEM, X-Ray, DSC, and TG analyses are also presented and discussed.

Performance optimization of a standard-flow hybrid rocket engine

A method for performance optimization of a standard-flow hybrid rocket engine is considered. The method is based on inserting an additional amount of an oxidizer into a solid propellant with a prescribed distribution of the oxidizer mass fraction along the solid propellant charge. An analytical dependence is derived for the oxidizer fraction distribution that ensures uniform combustion and high efficiency of the solid propellant charge.

Morphology of ceramic particles produced by plasma-chemical synthesis

Thermal and diffusion processes in the droplet weakly concentrated metal salt solution during its heating in the plasma chemical reactor, in order to synthesize metal oxide powders are considered. Numerical study is based on previously proposed physical-mathematical model. The results of numerical calculations are analyzed to assess the possible influence of the operation parameters of the reactor and the characteristics of the initial solution (precursor) on the morphology of the particles formed.

Turbidimetric method for measuring the parameters of submicron aerosols

A new turbidimetric method for determining the parameters of submicron aerosols was developed and implemented in hardware using a wide range of probe radiation wavelengths and high-speed video recording. The particle size distribution function is found using an original algorithm for solving the inverse problem of the optics of aerosols based on a direct search computational procedure..

Laser diagnostics of the centrifugal nozzle spray cone structure

A method for determining the three-dimensional distribution of droplet concentration in the centrifugal nozzle spray cone is proposed; the method is based on measuring the spectral transmission coefficient in laser scanning of the spray cone. The results of studying the spray cone structure depending on the pressure differential and the distance from the nozzle exit are presented.