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In the article constructs the criterion (test) that allows us to check the hypothesis on the homogeneity and independence of sampling elements of random variables having the continuous distribution. The constructed criterion is exact and, in contrast to the various criteria of the series, does not require the imposition of conditions on the sample size and conditions for the moments of random variables. The criterion does not depend on the distribution of the observed random variables and can be applied, including, for samples of small volume. This test is suitable for testing the hypothesis of homogeneity and independence of perturbations (errors) of regression models. Authors describe the methodology for applying the developed criterion for revealing the structural shifts observed in time series. The structural shift in 2008 is revealed in study of the dynamics of the Russian Federation gross domestic product in the period from 2000 to 2008 years.

Energetic polymers containing nitro, nitrato, and azido groups release high energy during combustion and thereby increase the performance of the systems. A number of energetic polymers have been found suitable for use as binders in high-performance propellant and explosive formulations. This review describes the synthetic aspects and applications of various modern energetic polymers for explosive formulations and propellants.

A mathematical model, laboratory setup description, and results of a numerical-experimental study of specific features of an unsteady two-phase flow of the air-ethanol fuel composition in the duct of a resonance gas-dynamic system (RGS) are presented. The basic specific features of ignition of the fuel mixture in the resonance cavity are detected. The conditions of ignition are determined, and the ignition delay time of the fuel composition in the RGS is estimated. The data obtained in this study can be used for modeling physical and chemical processes and for choosing liquid fuel injection modes satisfying the conditions of ignition of two-phase fuel mixtures in the RGS.

A new chemical reactor network model is developed to predict the emission of nitrogen oxides in an industrial combustion chamber operating on liquefied petroleum gas. The boundary conditions and operating parameters used for this model are typical operating conditions of an industrial combustion chamber. The global mechanism is developed by GRI-MECH 3.0 in the UW code. The model predictions are compared with experimental data. The chemical reactor network model provides an accurate estimation of nitrogen oxide emission.

This paper describes the model of the propagation of solid-phase exothermic reaction in a layer between inert materials with various thermal and physical properties. The model is implemented numerically. The relationships between the ignition time and the model parameters, as well as the behavior of some energy characteristics under various conditions in time (heat reserve in the heated layer and excess of enthalpy). The influence of the thermal and physical properties of inert materials on the temperature distribution in the sample in stationary and nonstationary regimes is demonstrated.

On the basis of the previously proposed model, the values of the self-diffusion coefficient of He, Ne, Ar, Kr, Xe, H₂, D₂, N₂, O₂, CO₂, NH₃, and CH₄ The previously proposed model is used to determine the values of the coefficient self-diffusion He, Ne, Ar, Kr, Xe, H₂, D₂, N₂, O₂, CO₂, NH₃, and CH₄ in the liquid and dense gaseous states, which were compared with the experimental data obtained at a pressure ≈200 MPa and a temperature ≈500 K. The calculations are carried out with the use of the state equation of these substances in the form of a modified Van der Waals model. The self-diffusion model was generalized for the case of mutual diffusion in binary mixtures, which is based on the modified model of the Van der Waals state equation for mixtures. The model coefficient of mutual diffusion for a great number of binary mixtures of the above-mentioned individual substances is determined, and the results are compared with the known data. Without special calibration for the experiment, the model correctly predicts the relationship of the self-diffusion and mutual diffusion coefficients (with their change by several orders of magnitude in the case where the density changes from gaseous to liquid) with both pressure and temperature. For most substances considered in the paper, the maximum deviations of calculations from the experiment do not exceed 30-50%.

Results of modeling propagation of a shock wave formed by an explosion of a spherical charge of a high explosive in a semi-infinite space bounded by a plane substrate are reported. Problems of the action of such a wave on objects rigidly fixed on the substrate (single prism and a set of prisms simulating an urban area) are considered. The computations are performed in a three-dimensional inviscid formulation with the use of the AUTODYN module of the commercial software package ANSYS. These numerical predictions are compared with experimental data on the static pressure in sensors mounted on the prism walls. A possibility of providing an adequate description of the unsteady flow pattern formed around the obstacles mounted on the substrate is demonstrated. Based on these numerical data, the intensity of the shock wave action on various objects is estimated.

The problem of interaction of an expanding spherical shock wave with a layer of particles is considered within the framework of the model of mechanics of continuous media with due allowance for granular pressure in the dense gas suspensions. The influence of particle collisions on the shock wave expansion process is analyzed. Generation of collision pressure and formation of shock wave structures in the gas suspension are found to be the governing factors of motion of the cloud of particles at the initial stage.

The influence of mineral additives (6.2-70% and water (15-54% to lignite on the possibility of its burning in an air flow in a continuous detonation regime in a radial vortex combustor 500 mm in diameter is studied. A syngas with a composition CO + 3H₂ is used for transporting the coal mixture and for promoting the chemical reaction. It is shown that regimes of continuous spin detonation, conventional combustion, and pulsed combustion may occur depending on the amounts of the mineral (TiO₂) added to coal, water, and syngas. The boundaries between the domains of existence of detonation and combustion are determined in the coordinates of the ratio of the syngas flow rate to the rate of consumption of the combustible portion of coal and the mineral component of coal and water. It is seen that the continuous spin detonation regime persists if the mineral additive fraction in the lignite mixture is up to 65% and the water fraction is smaller than 30%. It is also demonstrated that the syngas flow rate should be increased with increasing mineral additive fraction and increasing coal humidity in order to ensure burning of the combustible component of syngas.

The detonation properties of mechanically activated mixtures of ammonium perchlorate and aluminum were studied. The transition from combustion of low-density charges to detonation was investigated. Dependences of the detonation velocity of compacted charges with various types of aluminum on the activation time, the charge density and diameter were obtained. For compositions with nanosized aluminum, the detonation velocity was found to depend nonmonotonically on the reverse charge diameter, remaining almost unchanged in a certain range of charge diameters. It is shown that the joint use of mechanical activation and nanosized components of the composite explosive significantly increases the detonation capacity, reduces the critical diameter, and shifts the maximum on the detonation velocity vs. density curve to the highest charge densities.