Kinetic and gasdynamic processes in nonequilibrium molecular physics

Ratkowski

2018

Acta Phys. Pol. A

Nonlinear effects of planar magnetosound perturbations in a plasma are discussed. Plasma is non-adiabatic due to optically thin radiation and external heating. For these reasons, thermal instability of a plasma may appear which makes it acoustically active. The plasma is assumed to be initially homogeneous ideal gas with infinite electrical conductivity permeated by a straight magnetic field which is orthogonal to the trajectories of gas particles. The instantaneous dynamic equations which describe nonlinear effects of intense sound in quasi-isentropic plasma, are derived. Nonlinear interaction of periodic and aperiodic magnetoacoustic perturbations with the non-wave modes, are discussed. The conclusions concern dissipative or active behavior of magnetoacoustic perturbations which is determined by the kind of the heating-cooling function.

Section: Nonlinear Effects Which Associate With the Intense Magnetoacmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 94%

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On the Nonlinear Effects of Magnetoacoustic Perturbations in Optically Thin Quasi-Isentropic Plasmas

Ratkowski

2018

Acta Phys. Pol. A

“…The first example relates to a gas whose steady state is maintained by pumping energy into the vibrational degrees of molecule's freedom (Osipov, Uvarov, 1992;Clarke, McChesney, 1976). The quantity…”

Section: Examples: Gases With Excited Vibrational Degrees Of Moleculementioning

confidence: 99%

“…The non-equilibrium molecular physics began to develop quickly due to the laser revolution in physics and chemistry (Osipov, Uvarov, 1992;Clarke, McChesney, 1976). Since that, the attention is concentrated on media which may reveal anomalous dispersion and attenuation (Bauer, Bass, 1973;Molevich, 2001).…”

Section: Introductionmentioning

confidence: 99%

Standing Waves in a Rectangular Resonator Containing Acoustically Active Gases

2016

Archives of Acoustics

The distribution of perturbations of pressure and velocity in a rectangular resonator is considered. A resonator contains a gas where thermodynamic processes take place, such as exothermic chemical reaction or excitation of vibrational degrees of a molecule's freedom. These processes make the gas acoustically active under some conditions. We conclude that the incident and reflected compounds of a sound beam do not interact in the leading order in the case of the periodic sound with zero mean pressure including waveforms with discontinuities. The acoustic field before and after forming of discontinuities is described. The acoustic heating or cooling in a resonator is discussed.

Relations between magnetosonic perturbations as an indicator of a magnetosonic exciter and equilibrium parameters of a plasma

Contributions to Plasma Physics

2022

The thermodynamic relations between perturbation of pressure and perturbation of mass density and between components of velocity which specify a magnetosonic wave are theoretically studied. A planar flow with the wave vector forming a constant angle with the equilibrium magnetic field is investigated. The theory considers deviation from the adiabaticity of a flow due to some kind of heating–cooling function and thermal conduction of a plasma. It considers also the weak impact of nonlinearity. The thermodynamic relations and corresponding diagrams reveal the hysteretic character of irreversible processes in a plasma flow and may indicate damping and nonlinear parameters of a flow. They may indicate also the geometry of a flow, the equilibrium parameters of plasma, and specify a magnetosonic source. The harmonic and impulsive exciters are discussed in this connection.