St. Petersburg State University of Civil Aviation

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Saint Petersburg, Russia
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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.


Isaev S.A.,St. Petersburg State University of Civil Aviation | Baranov P.A.,St. Petersburg State University of Civil Aviation | Sudakov A.G.,St. Petersburg State University of Civil Aviation | Usachov A.E.,St. Petersburg State University of Civil Aviation
Technical Physics Letters | Year: 2014

The Navier-Stokes and Reynolds equations have been numerically solved by a factorized finite-volume method. The Reynolds equations were closed using the Menter shear-stress-transfer model modified with allowance for the curvature of flow lines. The obtained solution has been used to confirm expansion of the range of critical Mach numbers during modeling of a nonstationary flow past a thick MQ airfoil with slot suction in circular vortex cells. © 2014, Pleiades Publishing, Ltd.


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

The flow of fluid under the Joukowski tongue was studied through an irrigated soil layer into the underlying highly permeable water-bearing horizon containing head subsoil waters, the left semi-infinite part of the roof of which is simulated by an impenetrable base. In this case, the flow-around velocity at the point of the tongue base was assumed to be limited from above by the infiltration intensity related to the soil filtration coefficient. An arbitrary specification of the complex-velocity region, can result in beforehand unforeseen flow features such as unnatural flow separation or the outcome of the depression curve beyond the scope of the motion region. The analysis shows that the use of the semi-inverse method requires obligatory posterior verification of the partial solutions obtained with the purpose of estimating their physical reality.


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.


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


Isaev S.A.,St. Petersburg State University of Civil Aviation | Baranov P.A.,St. Petersburg State University of Civil Aviation | Sudakov A.G.,St. Petersburg State University of Civil Aviation | Ermakov A.M.,Kazan State Technological University
Technical Physics Letters | Year: 2015

The Reynolds equations closed using the Menter shear-stress-transfer model modified with allowance for the curvature of flow lines have been numerically solved using multiblock computational technologies. The obtained solution has been used to analyze subsonic flow past a thick (37.5% chord) airfoil with slot suction in circular vortex cells intended for the Ecology and Progress (Ekologiya i Progress, EKIP) aircraft project in comparison to a distributed (from the central body surface) suction at fixed values of the total volume flow rate (0.02121) and Reynolds number (105) in a range of Mach numbers from 0 to 0.4. This analysis revealed a significant (up to tenfold) decrease in the bow drag (determined with allowance for the energy losses) and a large (by an order of magnitude) increase in the aerodynamic efficiency of the thick airfoil containing vortex cells with slot suction, which reached up to 160. © 2015, Pleiades Publishing, Ltd.


Bereslavskii E.N.,St. Petersburg State University of Civil Aviation
Journal of Engineering Physics and Thermophysics | Year: 2011

In the hydrodynamic formulation, we solve the problem of plane steady filtration under a Zhukovskii sheet pile through an irrigated ground mass underlain by a highly permeable pressure stratum the left semi-infinite part of whose roof is modeled by an impermeable inclusion. Using the P. Ya. Polubarinova-Kochina method, we give a constructive solution of the problem and accurate analytical representations for characteristic dimensions of the flow pattern. Results of the numerical calculations and an analysis of the effects of all physical parameters of the model on filtration characteristics are presented. Consideration is given to limiting cases of flow associated with the absence of an impermeable inclusion as well as of backwater in the underlying well-permeable layer. © 2011 Springer Science+Business Media, Inc.


Bereslavskii E.N.,St. Petersburg State University of Civil Aviation
Doklady Physics | Year: 2011

The flow of a fluid is investigated under the Joukowski tongue through an irrigated soil bulk into an underlying strongly permeable water-bearing horizon containing underground water under pressure, the left-hand semi-infinite roofing part of which is modeled by an impermeable basis. Two cases are considered, when the flow velocity at the tongue edge is finite or infinite and the corresponding region of complex velocity ceases to be one-sheeted. An increase in the infiltration intensity, the tongue length, and the stratum thickness, and a decrease in the flow velocity at the tongue edge and the head, result in increasing value of water rise. An increase in the infiltration intensity, the flow around velocity, and both heads and a decrease in the massif thickness and the tongue lengths result in a decreasing value of water rise.

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