Effect of the addition of ultrafine aluminum powders on the rheological properties and burning rate of energetic condensed systems

The effect of small additives (1.25–5.00%) of ultrafine aluminum powders (UFAP) on the rheology and combustion of model four-component energetic condensed systems is studied. It is found that the addition of UFAP decreases the temperature of HMX decomposition. Small additives of UFAP increase the burning rate of model energetic condensed systems and decrease the exponent ν in the burning rate law without deteriorating the rheological characteristics of the model propellants. __________ Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 1, pp. 54–59, January–February, 2007.     

Physicomathematical model of the agglomeration of aluminum in the combustion of mixed condensed systems

Novosibirsk. Translated from Fizika Goreniya i Vzryva, Vol. 25, No. 1, pp. 39–48, January–February, 1989.     

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.     

Effect of material mass flows on the ignition of condensed systems containing solid-phase reaction products

We consider the problem of ignition of a preheated metallic wire covered with a layer of reagent with a low heat conductivity. Solutions are derived both by numerical and approximate analytical methods. An analysis is presented for the dependence of the critical ignition conditions on the reagent's Stefan flow and the heat release. The degeneration during the reaction of the explosive nature of the ignition related to a change in the effective heat release coefficient is described. Various criteria for defining the critical conditions are discussed.Tomsk. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 2, pp. 8–14, March–April, 1992.     

缩合磷酸铝的制备与应用

对缩合磷酸铝的制备、固化机理及其在无机胶黏剂、涂料、无机建材、陶瓷和无机模塑材料中的应用进行了综述,指出未来应加强缩合磷酸铝合成工艺和在不同领域应用及应用机理的研究,以促进该类环保材料的推广应用。     

Experimental and theoretical basis for improving the accuracy of measuring the burning rate of energetic condensed systems by a microwave method

Theoretical basis and practical ways to improve the accuracy of measuring the burning rate of energetic condensed systems by a microwave technique are considered. An analysis is made of the factors that reduce the measurement accuracy, in particular, edge effects, the non-evanescence of the waveguide, change in the effective diameter of the waveguide due to incomplete burning of the reinforcing composition, intrachamber pressure, curvature (roughness) of the burning surface. The components of the systematic measurement error are determined, the measurement error is calculated, and a numerical correction method for reducing the error to 4.5% is proposed.     

Combustion of boron-containing condensed systems

Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 1, pp. 51–53, January–February, 1992.     

Effect of the curvature of the burning surface of condensed energetic materials on the burning rate

Combustion of homogeneous condensed energetic materials (CEMs) with a curved burning surface is considered within the framework of the phenomenological theory of unsteady combustion. A dependence of the burning rate on the burning surface curvature is found. It is demonstrated that there exists a limiting surface curvature value above which self-sustained combustion is impossible. This limiting curvature depends on thermophysical and ballistic characteristics of CEMs. The existence of the limiting curvature of the burning surface offers an explanation of the critical conditions of combustion of homogeneous CEMs. Based on this hypothesis, the critical diameters of combustion of several homogeneous CEMs are calculated. The calculated results are in good agreement with available experimental data.     

Nonadiabatic dynamics of condensed phase rate processes

The study of quantum rate processes occurring in condensed phase environments is difficult because of the large number of degrees of freedom involved. Since a full quantum mechanical treatment is not computationally feasible, one is motivated to use mixed quantum-classical dynamical methods. This type of dynamics is applicable when one can single out a few degrees of freedom to be quantum in nature while treating the remainder classically. We describe a method that is based on the quantum-classical Liouville equation, which clearly prescribes the details of the coupling between the quantum and classical degrees of freedom. With the aid of this machinery, we show how to compute rate constants of reactions involving quantum particles immersed in a classical bath. We illustrate the use of this method on a model for proton transfer in a molecular complex dissolved in a polar solvent.     

Two and three phase equilibrium calculations for systems containing water

A recently proposed two-constant equation of state is used to predict the phase behaviour of systems exhibiting a water-rich liquid phase, a hydrocarbon-rich liquid phase and a vapor phase. The algorithm proposed is efficient and thermodynamically rigorous and it converges significantly faster than earlier models. Representative calculations are shown for the methane-n butane water system, the n butane-1 butane-water system, and a synthetic six-component hydrocarbon mixture containing waer.