V. Yu. Velikodnyi

Nonadiabatic excitation of iodine molecules in the translational disequilibrium zone of a shock wave

Short-lived peaks of nonequilibrium emission are detected at 320–350 nm in shock-wave fronts in He, Ne, Ar, and H2 containing from 0.1 to 3% iodine molecules. The effect is observed in the range of Mach numbers from 3.2 to 6.3 for initial pressures of the mixtures ranging from 133 to 2660 Pa. The emission observed is assigned to the electronic I2(D3Σ→B3Π) band, which is located at excitation energies 5.45→1.8 eV, i.e., significantly above the dissociation threshold of iodine molecules (1.54 eV). An analysis of the results shows that the leading role in the excitation of iodine molecules is played by high-energy collisions in the translational disequilibrium zone of the shock wave. The best description of the experimental data is achieved for the value of the effective collision energy in the front calculated on the basis of a numerical solution of the Boltzmann equation by a modified Tamm-Mott-Smith method. The absolute values of this energy under the conditions of the experiments performed are roughly 10 times greater than the mean collision energy in the equilibrium zone behind the shock wave. The probability of nonadiabatic supercollisions of the type I2+I2→I2(D3Σ)+I2−6.4eV exceeds the adiabatic values by a factor of 1015–1020.

The Rates of Nonequilibrium Physicochemical Processes in the Shock Wave Front in a Dense Gas Mixture

The possibilities of increasing the rates of physicochemical processes (PCP) occurring in shock waves (SW) have been recently investigated in a number of studies [1–5]. This effect was theoretically predicted and experimentally revealed [3]. A mode with different partial velocities and temperatures of the components is observed in the SW front in mixtures of gases with different masses and cross sections of particles. In addition, because of the comparability of the shock wave thickness and the free path, particles from regions before and after the shock wave may interact with one another. As a result, the possible physicochemical processes (the processes of excitation of internal degrees of freedom and the chemical reactions) will occur under nonequilibrium conditions. It is the objective of this study to calculate the maximal possible increase in the PCP rates (electron level excitation) in the SW front in a mixture of dense gases with different masses of particles. The calculation is to be performed using a kinetic equation of the Enskog type for the soft-sphere model.

Experimental study of the ignition of liquid hydrocarbon fuels and stabilization of their combustion by an arc discharge

The ignition of liquid hydrocarbon fuels and stabilization of their combustion by an arc discharge in a supersonic air flow are investigated experimentally. The discharge parameters and flame characteristics (ignition time lag) are determined. It is shown that the average energy deposited in the flow by the igniter is five orders of magnitude less than the kinetic energy of the main gas flow.

Theoretical investigation of nonequilibrium processes in shock wave in bubbly liquid

The effects related to a translational nonequilibrium at the shock wave front in a bubbly liquid flow with volume gas contents within 0.3 ≤ φ ≤ 0.98 have been theoretically studied. Analytical expressions for the longitudinal and transverse pressures, longitudinal and transverse temperatures, viscous stresses, and heat flux are obtained and the corresponding values are calculated for various Mach numbers and gas contents in the bubbly flow. The influence of the translational nonequilibrium at the shock wave front on the bubble fragmentation process is considered.

Properties of erosive discharge in a gas-dispersion flow

Erosive discharge in the flow of a gas-dispersion mixture (air with dispersed microscopic drops of an electrolyte) has been experimentally studied. The products of erosion were obtained by coating the electrodes with a wax (this method was originally used by N. Tesla). Two phenomena were observed behind the discharge gap, i.e., (i) a linear breakdown in the form of a bead lightning (within 0.5–1 m behind the interelectrode gap) and (ii) the appearance of long-lived plasma formations (plasmoids). Cotton-like wax deposits formed on glass slides were examined in optical microscopes at various magnifications. The propagation of long-lived plasmoids in an applied magnetic field was monitored by a high-speed TV camera. Waveforms of a current transferred by the gas-dispersion flow were measured using a conducting screen. Based on these data, a self-consistent physical model is formulated, which describes the generation, evolution, and decay of the long-lived plasmoids.

Investigation of the ignition of liquid hydrocarbon fuels with nanoadditives

During our experimental studies we showed a high efficiency of the influence of nanoparticle additives on the stability of the ignition of hydrocarbon fuels and the stabilization of their combustion in a highfrequency high-voltage discharge. We detected the effects of a jet deceleration, an increase in the volume of the combustible mixture, and a reduction in the inflammation delay time. These effects have been estimated quantitatively by digitally processing the video frames of the ignition of a bubbled kerosene jet with 0.5% graphene nanoparticle additives and without these additives. This effect has been explained by the influence of electrodynamic processes.

Cluster-Impact Fusion of Light Nuclei

A number of researchers, who performed experiments to investigate the interaction of charged clusters of heavy water (D2O)+n, accelerated in an electric field to an energy of 300 keV, with a wall of deuterated materials (TiD, (C2D4)n), revealed an “anomalously” high yield of products of the reaction 2D + 2D with increasing size of clusters. It is demonstrated in this paper that the “anomalously” high yield of products of the reaction 2D + 2D with increasing size of clusters may be caused by nonequilibrium effects arising as a result of collective interaction between 2D and heavy atoms of O and Ti by the Fermi mechanism. Based on the results of analysis of experimental data and prediction results, we suggest methods of realizing the process of fusion of light nuclei at a close-to-maximal rate at a relatively low average energy per nucleon in a cluster of about 0.005 to 0.8 keV. In principle, no novel breakthrough technologies are required to realize the suggested methods (standard commercially available equipment is adequate for the purpose). A characteristic feature of the suggested devices consists in their small dimensions and a relatively low value of the initial energy input, which offers possibilities for their utilization as a source of energy in flights to outer planets of the solar system and at stations on those planets.

Effects of translational nonequilibrium in the shock wave front in dense gases and liquids

On the basis of the generalized Enskog kinetic equation, the problem of the structure of a shock wave in dense reacting gases and liquids is solved. It is shown that the physicochemical processes in the zone of translational nonequilibrium (ZTN) in the shock wave front do not obey the Arrhenius kinetics. The rates of high-threshold processes in the ZTN in the shock wave front may exceed these rates in equilibrium behind the front by a factor of 106 and more. An analytical expression is obtained for the rate constant of nonequilibrium processes in the front. Comparison of the results of calculation of the yield of products with broken double bond in the benzene molecule with the experimental data reveals that the formation of these products proceeds by the mechanism of nonadiabatic collisions realized under highly nonequilibrium conditions.