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Parametric analysis of mathematical models of amyl nitration in a continuous stirred tank reactor and a tube reactor was erformed. Curves of steady states versus control parameters, multiplicity and neutrality curves of the steady states, and parametric and phase portraits of the system were plotted. The critical values of the input concentration and the heat<!dash!>transfer coefficient leading to disturbance of the steady<!dash!>state nitration of amyl were obtained for the tube reactor. P.30-36

When specimens pressed from a chromium powder react with nitrogen at pressures of 1<!ndash!>8 MPa and relative densities of 0.47<!ndash!>0.55, unsteady combustion of a nonthermal nature, which was not known previously, is observed. It is shown that the unsteadiness is due to cracks formed ahead of the combustion front. The specimens fail as a result of an increase in the condensed-phase volume upon formation of nitrides. P. 37-40

A three-dimensional mathematical model is constructed for the gasless combustion of a solid circular cylindrical specimen. The steady-stated spin regimes obtained were studied by numerical methods. The structure and mechanism of spin combustion are illustrated and discussed. It is shown how the space-time pattern of spin-wave propagation is complicated as the radius of the cylinder increases. Spin propagation of the front can proceed in a regime in which the structure of the front does not change (for small radii of the sample) or in an unsteady regime, in which the structure of the front undergoes numerous changes over a period. In the second case, a synchronous or alternate <!ldquo!>flicker<!rdquo!> of the sites is observed on the surface of the cylinder. The nonuniqueness of the combustion regimes is detected. It is shown that the average velocity of propagation of the spin-combustion front is of the order of the velocity of steady front propagation under adiabatic conditions. P. 41-48

The mechanism of combustion in a multilayer system of disks pressed from a 5Ti+3Si mixture under compressive stresses was studied experimentally. In the examined range of process parameters, the existence of only the relay-race combustion regime is revealed. The times of combustion transfer between the disks are determined. P. 49-53

The paper deals with the combustion of a SiO₂-Al stoichiometric mixture after mechanochemical treatment in activator mills of two types: mills using predominantly shear loading and those using sheardynamic compression. It is shown that treatment in different loading regimes, leading to different energy states of the material, and the use of modifying organic additives change significantly the ignition and combustion temperature of the mixture. Modification of the surface of the quartz particle by mechanochemical treatment in the presence of butanol or polystyrene and aluminum activates the combustion process, thus ensuring greater completeness of the oxidation-reduction reaction. P. 54-59

The combustion of a mixture of molybdenum and carbon activated by a high-energy magnesium-fluoroplastic mixture was studied. The adiabatic combustion temperature and the equilibrium compositions of the combustion products were calculated and, experimental dependences of the combustion temperature and rate on the main parameters of the process are obtained. It is shown that the activation of the formation of molybdenum carbides is of a thermal nature. The two observed mechanisms of formation of molybdenum carbides are found to differ in combustion temperature: at T= 2470 K, formation of carbides proceeds by a diffusion mechanism, and at T = 2470 K it proceeds by crystallization from a melt. The possibility of synthesis of single-phase Mo₂C in the combustion regime is shown. P. 60-64

A new method for an experimental study of burning processes in condensed substances is suggested, based on the statement and solution of inverse problems. An inverse problem of reconstructing the erosive burning rate of solid propellants from experimental data is formulated. The choice of an approach to solving the problem by the joint application of well<!dash!>known methods for inverse problem solution and specific features of experimental studies of burning processes, in particular, erosive burning, has been justified. The problem solution is illustrated by a numerical example. The testing involves a comparative analysis of two optimization methods: although both methods are characterized by an identical accuracy, the steepest descent method has a higher rate of convergence for this class of problems than the conjugate gradient method. P. 65-70

The paper presents estimates of the dynamic characteristics of unsteady combustion of a solid rocket propellant in a combustion chamber with in pressure is varied automatically by a specified program. The estimates are obtained from experimental data by mathematical modeling with the use of a simplified model of unsteady processes in the combustion chamber. A linear approximation is obtained for the transfer function of the unsteady-combustion rate, and its coefficients are expressed analytically in terms of the parameters of a simplified model of unsteady processes. Results of identification of the model for several fragments of experimental processes are given. Families of approximate frequency characteristics of the unsteady-combustion rate are constructed, analyzed, and compared with available results. P. 71-80

The paper describes a new probe method for determining the quantitative composition of solid-propellant combustion products at temperatures of 25003200 K and pressures of 48 MPa under conditions typical of rocket motor conditions. A twostep probe is described, which allows a sample to be frozen without passing through the main shocks inside the sampler. The gas dynamics and the kinetics of chemical reactions were simulated to asses the correctness of sampling. It is shown that during sampling from a flame, the relative change in concentrations for most of the stable components does not exceed 3, and for H₂ and O₂, it does not exceed 12. The method permits additional operations with a sample, in particular, separation of CO and N₂ with subsequent analysis on a timeofflight mass spectrometer. The CO and CO₂ concentrations in the combustion products of the model composite solid propellant ammonium dinitramide ADN with polycaprolactone pCLN were determined at a pressure of 4 MPa. P. 81-91

The effect of gaseous combustion environment on particle size distribution and chemical compositions of condensed combustion products of a model propellant containing ammonium perchlorate, binder, and 23.4% aluminum was studied. Experiments were conducted at pressures of 0.6, 4.0, and 7.5MPa. Oxide particles with sizes of 1.2<!ndash!>60 <!mgr!>m and agglomerates with sizes from 60 <!mgr!>m to maximum were investigated. In experiments with nitrogen and helium, the difference in the mean sizes of the sampled agglomerates does not exceed the experimental error. The difference in the amount of unreacted <!lpar!>metallic<!rpar!> aluminum in the agglomerates sampled in nitrogen and helium is also negligible. Replacement of nitrogen by helium affects the size distribution of the oxide particles by increasing the mass fraction of particles with sizes of 1.2<!ndash!>10 <!mgr!>m, and this effect is enhanced with pressure. P. 92-100