V. G. Prokof’ev

Gasless combustion in two-layer structures: A theoretical model

Combustion of two-layer structures formed by a lower layer of highly caloric porous reactive mixture and an upper layer of low-melting inert metal is analyzed theoretically. During combustion, the melted upper layer flows into a porous combustion product to yield a composite material. The modes of combustion and material synthesis are characterized.

Effect of the phase transition on three-dimensional unstable regimes of gasless combustion

The thermal effect of the phase transition on unstable regimes of gasless combustion is numerically studied within the framework of the model of solid flame combustion of a cylindrical sample. The closer the phase transition temperature to the burning temperature, the more pronounced the effect of the phase transition on the combustion character. In this case, the combustion front surface is noticeably smoothed owing to reduction of temperature gradient values. A relationship between the change in the combustion modes considered in the study and the change in the phase transition parameters is found. An unsteady periodic symmetric mode of combustion with ring-shaped trajectories of motion of combustion sites over the side surface is obtained.

Influence of mechanical activation on gasless combustion of three-component SHS systems with competing (parallel) reactions

AbsrtactSuggested is a mathematical model that describes the process of mechanical activation (MA) in three component SHS systems with competing (parallel) reactions. Preliminary MA of starting blends and their mixtures was found to change combustion modes and result in non-uniqueness of burning velocity and product composition.

Combustion of Granulated Gasless Mixtures in a Flow of Inert Gas

Combustion of granulated gasless mixtures in a flow of inert gas was numerically explored in terms of a two-temperature approximation to mathematical modeling of unsteady combustion. The regimes of combustion wave propagation were analyzed as a function of gas flow characteristics and parameters of interphase heat transfer.

Effect of Melting of Inert Components and Melt Flow on Nonstationary Combustion of Gasless Systems

The effect of the thermocapillary flow of melt of inert components of gasless mixtures on the spinning combustion regimes of cylindrical samples has been studied numerically. The change in the structure of the spinning combustion wave due to a change in the sample radius is discussed, and new spinning combustion regimes are found. Increasing the melt flow velocity leads to stabilization of the combustion, i.e., to the transition from spinning regimes to the stationary propagation of the combustion wave.

Ignition and unstable regimes of gasless combustion of a disk-shaped sample

The effect of ignition conditions and the parameters of the melting of the inert component on unstable combustion modes is studied numerically using a model of solid-flame combustion of a disk. It is shown that the shape of the heated region initiating combustion of the disk determines the number and trajectories of hotspots of the self-propagating combustion zone. The effect of the phase transition on the combustion characteristics is the more pronounced the closer the phase transition temperature to the combustion temperature. In this case, the combustion front takes the shape of a ring.

Spinning combustion regimes in gasless systems containing one melting component

The propagation of a gasless combustion wave in a continuous cylindrical sample pressed from a mixture of solid reactants has been numerically simulated with allowance made for the melting of one of the components. The melting point of the component has been assumed to be equal to the reaction rate “cutoff” temperature. Symmetric and asymmetric combustion regimes can take place in the sample, depending on the sample radius. The reaction rate cutoff temperature is an additional perturbation factor in the propagation of the gasless combustion wave.

Combustion of gasless systems in conditions of uniaxial loading

Combustion of gasless SHS systems in conditions of uniaxial loading was mathematically modeled in approximation of viscous compressible liquid and numerically analyzed. Boundaries of the deformation zone were found to depend on the melting point of one of the reagents and on the volume fraction of refractory component in combustion product. Burning velocity, strain rate, and final product porosity were estimated as a function of applied load and green porosity. Outlined was the applicability range for our model to adequate description of deformation processes taking place during combustion of gasless SHS systems.

On the theory of combustion and synthesis of composite materials in the field of mass forces

The formation of a composite material during combustion of a two-layer sample in a centrifugal device was studied by mathematical modeling. The liquid combustion products of the upper layer flow into the lower porous layer under the action of the centrifugal force and initiate its combustion to form a composite material. The critical conditions for the passage of the combustion wave from the upper to the lower layer of the sample are determined depending on the gravitational overload and initial porosity. Dependences of the burning velocity and the impregnation depth of the lower layer on its porosity and overload are obtained.