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Bereslavskii E.N.,St. Petersburg State University of Civil Aviation
Doklady Physics | Year: 2016

Within the framework of the theory of plane steady filtration of an incompressible fluid according to Darcy’s law, two limiting schemes modeling the filtration flows under the Joukowski tongue through a soil massif spread over an impermeable foundation or strongly permeable confined water-bearing horizon are considered. © 2016, Pleiades Publishing, Ltd.

Zvereva G.,St. Petersburg State University of Civil Aviation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

In the work the influence of the processes characteristic for atmospheric pressure heavy inert gases discharge plasma on the value of the first Townsend ionization coefficient were investigated. Krypton plasma was considered. Calculations have shown that the greatest impact on the value of the first Townsend ionization coefficient has dissociative recombination of molecular ions, followed by descending influence processes occur: stepwise ionization, the electron-electron collisions and superelastic ones. The effect of these processes begins to appear at concentrations of electrons and excited particles higher than 1012 cm-3. At times shorter than the time of molecular ions formation, when dissociative recombination is absent, should expect a significant increase of the ionization coefficient. © 2016 SPIE.

Isaev S.A.,St. Petersburg State University of Civil Aviation | Leontiev A.I.,Moscow State Technical University
Journal of Engineering Physics and Thermophysics | Year: 2010

This paper analyzes the state of the art of numerical and partly physical simulation of convective heat transfer in the vicinity of dimpled reliefs on one of the walls of narrow plane-parallel channels. We show that there is a mismatch and spread of the results of these investigations, their conclusions lack substantiation, and there are "white spots" in the problems under consideration and in the methods of their investigation. Several physical experiments have been analyzed, and the correlation between the calculated predictions and measurement data has been discussed. In conclusion, the thermohydraulic characteristics of various dimpled reliefs are compared, and the advantage of oval dimples over spherical ones is demonstrated. © 2010 Springer Science+Business Media, Inc.

Bereslavskii E.N.,St. Petersburg State University of Civil Aviation
Journal of Engineering Physics and Thermophysics | Year: 2015

Within the framework of the Darcy′s theory of plane steady fi ltration of an incompressible liquid, two limiting schemes are considered that model fi ltration fl ows under a Zhukovskii sheet pile through a large mass of ground underlain by an impermeable base or by a permeable water-bearing pressure horizon. For purposes of analyzing these schemes, mixed boundary-layer problems of the theory of analytical functions are formulated that are solved with the aid of the Polubarinova-Kochina method. Based on these models, algorithms have been developed for calculating a saturation zone in those cases where, while considering the motion of water, one has to take into account the exposure of fl ow pattern to the combined effect of such important factors as backwater from the side of the impermeable base or of the underlying well permeable water-bearing bed, evaporation or infi ltration on the free groundwater surface, as well as the ground capillarity. © 2015 Springer Science+Business Media New York

Bereslavskii E.N.,St. Petersburg State University of Civil Aviation
Doklady Physics | Year: 2013

The linear differential equation of the Fuchsian class with six regular singular points, which corresponds to the problem of conformal mapping of circular hexagons in polar networks with two sections, is considered. It is shown that when fixing the parameter, which characterizes the deviation of the radii of the circles constituting the opposite sides of the polygon, on which the sections can appear, the configuration and mutual arrangement of the latter depend substantially not only and not even mainly on the known properties of θ functions, based on which the partial solutions of the equation under consideration are constructed, but mainly on the ranges of varying the unknown constants of the conformal mapping, which enter the expressions for imaging functions. The results of numerical calculations are presented. © 2013 Pleiades Publishing, Ltd.

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