arXiv subjects

O. V. Kliushnychenko

Publications and source records attributed to O. V. Kliushnychenko.

4 recordsLinked to original sources

arXiv2018

Effects of Collectively Induced Scattering of Gas Stream by Impurity Ensembles: Shock-Wave Enhancement and Disorder-Stimulated Nonlinear Screening

We report on specific effects of collective scattering for a cloud of heavy impurities exposed to a gas stream. Formation is presented of a common density perturbation and shock waves, both generated collectively by a system of scatterers at sudden application of the stream-inducing external field. Our results demonstrate that (i) the scattering of gas stream can be essentially amplified, due to nonlinear collective effects, upon fragmentation of a solid obstacle into a cluster of impurities (heterogeneously fractured obstacle); (ii) a cluster of disordered impurities can produce considerably stronger scattering accompanied by enhanced and accelerated shock wave, as compared to a regularly ordered cluster. We also show that the final steady-state density distribution is formed as a residual perturbation left after the shock front passage. In particular, a kink-like steady distribution profile can be formed as a result of shock front stopping effect. The possibility of the onset of solitary diffusive density-waves, reminiscent of precursor solitons, is shown and briefly discussed.

cond-mat.stat-mech↗

arXiv2016

Attraction/repulsion switching of non-equilibrium depletion interaction caused by blockade effect in gas of interacting particles. II

The effect of concentration-dependent switching of the non-equilibrium depletion interaction between obstacles in a gas flow of interacting Brownian particles is presented. When increasing bath fraction exceeds half-filling, the wake-mediated interaction between obstacles switches from effective attraction to repulsion or vice-versa, depending on the mutual alignment of obstacles with respect to the gas flow. It is shown that for an ensemble of small and widely separated obstacles the dissipative interaction takes the form of induced dipole-dipole interaction governed by an anisotropic screened Coulomb-like potential. This allows one to give a qualitative picture of the interaction between obstacles and explain switching effect as a result of changes of anisotropy direction. The non-linear blockade effect is shown to be essential near closely located obstacles, that manifests itself in additional screening of the gas flow and generation of a pronounced step-like profile of gas density distribution. It is established that behavior of the magnitude of dissipative effective interaction is, generally, non-monotonic in relation to both the bath fraction and the external driving field. It has characteristic peaks corresponding to the situation when the common density "coat" formed around the obstacles is most pronounced. The possibility of the dissipative pairing effect is briefly discussed. All the results are obtained within the classical lattice-gas model.

cond-mat.stat-mech↗

arXiv2015

Switching of non-equilibrium depletion force caused by blockade effect

The concentration-dependent switching of the non-equilibrium depletion forces between obstacles in an interacting Brownian gas flow is presented. It is shown that this switching is caused by the blockade effect for the gas particles. With increasing equilibrium gas concentration, the gas particles blockade causes the obstacle wake inversion (trace profile turn-over) that, in turn, leads to the change of sign of dissipative interaction. Some non-linear effects such as formation of a cavity-like sparse wake behind the obstacle and the dissipative pairing effect are discussed briefly. The results are obtained within the lattice gas model in the mean-field approximation.

cond-mat.stat-mech↗

arXiv2012

Induced long-time correlations in a two-component lattice gas

The distinguishability of at least two species of particles in the classical lattice gas with no interactions except hard-core exclusion entails additional interparticle correlations. A nonlinear mixing flow appears and manifests itself most pronounced in the case of significant difference between mobilities of species. It may result in the induced correlations for the slow component mediated by the fast one. In the quasi-one-dimensional case, the long-time correlations are demonstrated to take place in the slow component, that is similar to the hydrodynamic correlations between colloidal particles. In the adiabatic approximation, these correlations may come into play only in the non-equilibrium case with the flow of the fast component present in the system.

cond-mat.stat-mech↗