Effect of negative ions on probe measurements in a chemically reacting plasma at negative probe potentials

Probe measurements in a chemically reacting plasma provide information about certain parameters of the medium, for example, the effective ionization rate [1, 2]. At atmospheric pressure in a low-temperature plasma containing electronegative components with significant electron affinity (of the order of or greater than 1.5 eV) considerable negative ion concentrating may occur. The effect of the negative ions on the volt-ampere characteristic (VAC) of the probe when the chemical reactions in the plasma are assumed to be frozen was investigated in [3, 4]. Here, the VAC is obtained for negative probe potentials with allowance for ionization and electron attachment reactions whose characteristic lengths are of the order of the dimensions of the region disturbed by the probe. Moscow. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 163–169, September–October, 1988.     

Stability of quasilongitudinally propagating solitons in a plasma with hall dispersion

By analogy with the generalization obtained in [16] for the Korteweg-de Vries equation, the derivative nonlinear Schrödinger equation is extended to the weakly non-one-dimensional case. On the basis of the equation obtained the stability of solitons propagating at small angles to the undisturbed magnetic field relative to non-one-dimensional perturbations is investigated.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 159–165, March–April, 1987.     

Effect of ion heat fluxes on the stability of an anisotropic collisionless plasma

Small perturbations of an unbounded volume of anisotropic collisionless plasma in a strong magnetic field are studied on the basis of MHD equations. It is assumed that there are present in the plasma ion heat fluxes connected with the third-order moments of the ion distribution function. The dispersion equation obtained, determining the velocity of five types of waves, is analyzed. In the space of the undisturbed plasma parameters the regions of values in which small perturbations are damped exponentially with time are found.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.2, pp. 153–157, March–April, 1993.     

Slip boundary conditions on a catalytic surface in a multicomponent gas flow

The boundary conditions for the velocity slip and temperature and concentration jumps on the surface of a body in a rarefied multicomponent gas flow are obtained. The mathematical treatment is given in detail because of the need to examine critically some previous results which disagree with each other in spite of the fact that the initial premises and the methods of solution were the same. The results of this study, which are given in a convenient form, represent the boundary conditions for both the simplified and the complete Navier-Stokes equations in problems of hypersonic rarefied gas flow past bodies with a catalytically active surface.Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 159–168, January–February, 1996.     

初始温度对CO2抑爆作用的影响

将CO₂充入的液化石油气中并进行点火,研究不同初始温度下CO₂对多元混合气液化石油气爆炸的抑制作用。实验显示:初始温度15℃时CO₂体积分数达到36%时,混合气体退出可爆范围,临界氧浓度为12.8%;初始温度50℃时CO₂体积分数达到39%时,混合气体退出可爆范围,临界氧浓度为12.2%。结果表明:CO₂对液化石油气爆炸的抑制效果在一定程度上要受环境温度的影响。     

Effect of dissipative processes on compression flows in a plasma accelerator channel

Plasma flows in coaxial channels with a truncated central electrode are accompanied by compression and heating of the plasma on the channel axis [1–4]. Such flows were calculated in [1, 4] within the framework of a simple MHD model and by simple numerical methods and, accordingly, the results reflect only the basic qualitative characteristics of compression flows. Below, these flows are investigated in greater detail on the basis of a more accurate physical model with allowance for the finite conductivity, heat conduction and radiation of the plasma and impurities. The cases of anisotropic and classical isotropic heat conduction are considered. The numerical method employed is based on two finite-difference schemes: SHASTA-FCT [5–7] and TVD [8, 6]. The main advantage of these methods is the high resolution of the shock waves and contact discontinuities, which is highly desirable in describing compression flows. The calculations relate to the case of a fully ionized hydrogen plasma.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 102–109, May–June, 1991.In conclusion, the author wishes to express his gratitude to K. V. Brushlinskii and A. I. Morozov for frequent discussions and to K. P. Gorshenin for the use of his calculation results.     

Velocity of sound in a multicomponent medium at rest

The Kuropatenko model is considered, as applied to a multicomponent medium where the number of the sought functions coincides with the number of equations. The velocities of sound in a multicomponent medium at rest are determined. A formula of a polynomial of power N whose positive roots are squared velocities of sound in a medium with N components is derived. For N = 2, the values of two velocities of sound are determined in explicit form. It is demonstrated that the thus-found maximum value of the velocity of sound in a two-component medium containing nitrogen and oxygen with volume concentrations corresponding to air differs (in dimensionless form) from the velocity of sound in air by less than 0.3%. Numerical calculations predict the existence of three velocities of sound in a three-component medium. If the velocity of sound in all N components is identical, it is proved that the maximum velocity of sound in such a medium equals this velocity, and there is only one more velocity of sound in the medium, which has a lower value. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 35–44, May–June, 2008.     

Motion of a nonisothermal multicomponent sorbable mixture in a porous medium

The numerical solutions of a system of quasilinear equations in partial derivatives, describing the motion of a nonisothermal multicomponent sorbable gas mixture (or mixture of liquids) through a porous saturated medium consisting of porous grains and incapable of undergoing deformation, are analyzed; the conditions for the convergence of the iteration process used in solving the difference scheme and for the stability of the numerical solutions are obtained; the necessary and sufficient conditions for the existence of solutions of the traveling-wave type, permitted by the system of equations of motion, are also analyzed.     

Examples of the simplest boundary conditions for electron and ion concentrations and electron and heavy-particle temperatures

Examples of boundary conditions in certain particular cases are considered. The conditions proposed in [1, 2] can be used for any plasma component The boundary conditions for the same wall will generally be distinct for each of the components.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 169–172, November–December, 1976.