K. N. Volkov

Kingston University London, Londinium, England, United Kingdom

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Publications (36)5.5 Total impact

  • K. N. Volkov
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    ABSTRACT: The features of a simplified approach to coupled thermal analysis problems as based on the integration of the energy equation for a viscous compressible gas are discussed. The gas velocity field is assumed to be frozen, and a single iteration is run to update it at each step of the coupling procedure. The equation describing the temperature distribution in a solid is discretized using the finite element method, while the Navier-Stokes equations describing the velocity and gas temperature distributions are discretized using the finite-volume method. The system of difference equations resulting from the finite-volume discretization is solved by applying a multigrid method and the generalized minimal residual method. The capabilities of the approaches developed are demonstrated by solving several model problems. The accelerations of the computational algorithm obtained with the use of the full and simplified approaches to the solution of the problem and various methods for solving the system of difference equations are compared.
    Computational Mathematics and Mathematical Physics 04/2013; 53(4). · 0.41 Impact Factor
  • K N Volkov, V N Emelyanov
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    ABSTRACT: Formation, interaction and destruction of coherent structures play an important role in the propagation of the coherent beam through the environment and the occurrence of optical aberrations. The issues related to modeling and simulation of aero-optical effects in a free mixing layer and free round turbulent jet are considered. A semi-empirical model is developed to study the distortion of the phase function of the coherent beam, induced by turbulent flow fluctuations. Large-eddy simulation of free shear flows is performed. The results computed with the semi-empirical model and numerical results are compared with the experimental data and data computed with the Reynolds-averaged Navier–Stokes equations. The results obtained are beneficial for design and optimization of systems based on coherent optical adaptive technique.
    Journal of Physics Conference Series 12/2011; 318(4):042062.
  • K. N. Volkov
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    ABSTRACT: Results of large eddy simulations in a subsonic isothermal turbulent jet exhausting from a circular nozzle into a submerged space or a cocurrent flow are presented. The flow is described by space-averaged Navier-Stokes equations and by the RNG model of subgrid scale viscosity. Results computed for different values of the cocurrency parameter are compared with available results of numerical simulations and experimental data. The results obtained are found to agree well with measured data and to confirm the basic laws of variation of gas-dynamic and fluctuating parameters of submerged and cocurrent jets. Key wordsjet–turbulence–large eddy simulation–cocurrent flow
    Journal of Applied Mechanics and Technical Physics 01/2011; 52(1):48-56. · 0.25 Impact Factor
  • K. N. Volkov
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    ABSTRACT: Numerical modeling of inviscid compressible gas flow past a linear cascade of airfoils executing small harmonic translational and rotational vibrations is carried out. The control volume method on moving unstructured grid structures is used for discretization of basic equations. The influence of the frequency and phase characteristics of the airfoils on the pressure distribution over their surface and the lift coefficient is investigated. The results of numerical calculations are compared to the available calculated and experimental data. Keywordsairfoil cascade–unsteady flow–numerical modeling
    Journal of Engineering Physics and Thermophysics 01/2011; 84(2):392-401.
  • K. N. Volkov
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    ABSTRACT: The turbulent flow and coupled heat transfer in the cavity between the rotor and stator is numerically simulated. Reynolds-averaged Navier-Stokes equations closed with equations of the k-ɛ turbulence model are used to calculate the viscous compressible gas flow characteristics and heat transfer; the unsteady heat conduction equation is used to calculate the temperature field in the metal. The influence of the mass flow rate of the coolant on the flow structure and efficiency of cooling of the rotor and stator walls is studied. The calculated results are compared with experimental data. Keywordsturbulence–coupled heat transfer–cavity–rotation–numerical simulation
    Journal of Applied Mechanics and Technical Physics 01/2011; 52(3):436-449. · 0.25 Impact Factor
  • K. N. Volkov
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    ABSTRACT: Numerical modeling of the turbulent flow and conjugate heat exchange in a cavity bounded by a rotor and a stator is carried out. Coupled thermal calculations are based on the unsteady heat-conduction equation describing the temperature distribution within a solid and Reynolds-averaged Navier–Stokes equations closed using the k–ε turbulence model, which allow calculation of the velocity, pressure, and temperature distributions in the fluid-filled region. The space-time distributions of the temperature and the heat flux on the metal–fluid interface are obtained in two- and three-dimensional formulations of the problem on a structured and an unstructured grid. Keywordsconjugate heat exchange–cavity–numerical modeling–turbulence
    Journal of Engineering Physics and Thermophysics 01/2011; 84(2):382-391.
  • Source
    Konstantin N Volkov
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    ABSTRACT: Simulation of turbulent gas-particle flows inside combustion chambers of en-ergy systems is performed. An advanced model of turbulent particulate flow, which includes effects of particle stochastic motion (particle dispersion) is developed. Numerical calcu-lations are performed by the Eulerian–Lagrangian approach for the fluid and particles. Fluid flow calculations are based on Reynolds-averaged (RANS) or filtered Navier–Stokes (LES) equations. The solid phase is treated by the Lagrangian approach, which means that particles are followed in time along their trajectories through the flow field. At ev-ery given time step, the new position of the particle and its new velocity are calculated according to the forces acting on the particle. The inclusion of particle combustion and particle stochastic evolution in modeling of particle dynamics allows the proposed model to realistically simulate the flow field inside a combustion chamber. Substantial knowledge was obtained about particles dynamics as well as their interactions with internal turbulent flow. The two-phase model developed reasonably explains computational and experimental data, in particular, it explains the formation of regions of irregular particles concentration in internal duct flow induced by wall injection of fluid and particles.
    07/2010;
  • K. N. Volkov
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    ABSTRACT: A semi-empirical model is developed to study distortions of the phase function of a coherent beam, which are induced by turbulent fluctuations of flow parameters. Large eddy simulations of the boundary-layer and mixing-layer flows and also of related aero-optical effects are performed. Results of numerical calculations are compared with results of physical experiments and with data obtained by solving the Reynolds-averaged Navier—Stokes equations. Key wordsturbulence-aero-optical effects-large eddy simulation-boundary layer-mixing layer
    Journal of Applied Mechanics and Technical Physics 01/2010; 51(6):827-838. · 0.25 Impact Factor
  • K. N. Volkov
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    ABSTRACT: A multigrid method is proposed for solving the system of difference equations obtained via the finite-volume discretization of the Euler or Navier-Stokes equations on an unstructured mesh. A sequence of nested unstructured grids is generated via collapsing faces that take into account the features of the problem (inviscid/viscous). The capabilities of the approach are demonstrated by computing inviscid and viscous compressible uniform flows around an airfoil on structured, unstructured, and hybrid meshes. The topology of grids of different levels is described. Their quality and the influence of the grid structure on the convergence factor of the multigrid method are discussed. Keywordsmultigrid method-unstructured mesh-finite-volume method-Euler equations-Navier-Stokes equations-gasdynamic problems
    Computational Mathematics and Mathematical Physics 01/2010; 50(11):1837-1850. · 0.41 Impact Factor
  • Source
    Konstantin N. Volkov
    Engineering Letters. 01/2010;
  • K. N. Volkov
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    ABSTRACT: Low-velocity inviscid and viscous flows are simulated using the compressible Euler and Navier-Stokes equations with finite-volume discretizations on unstructured grids. Block preconditioning is used to speed up the convergence of the iterative process. The structure of the preconditioning matrix for schemes of various orders is discussed, and a method for taking into account boundary conditions is described. The capabilities of the approach are demonstrated by computing the low-velocity inviscid flow over an airfoil.
    Computational Mathematics and Mathematical Physics 01/2009; 49(10):1789-1804. · 0.41 Impact Factor
  • K. N. Volkov
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    ABSTRACT: Methods for setting and realizing wall boundary conditions numerically in calculating turbulent flows is considered. A method for realizing weak boundary conditions on the wall with discretization of Reynolds-averaged Navier–Stokes equations by the control volume approach is discussed. The results of calculations for a number of model problems obtained within the framework of different approaches to the near-wall modeling are compared to the data of the physical experiment and the available correlation dependences. The grid dependence of the solution in using the method of near-wall functions is compared to that in using weak boundary conditions.
    Journal of Engineering Physics and Thermophysics 01/2009; 82(3):466-475.
  • K. N. Volkov
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    ABSTRACT: An unstructured-grid discretization of the Navier-Stokes equations based on the finite volume method and high-resolution difference schemes in time and space is described as applied to fluid dynamics problems in two and three dimensions. The control volume is defined as the cell-vertex median dual control volume. The fluxes through the faces of internal and boundary control volumes are written identically, which simplifies their software implementation. The gradient and the pseudo-Laplacian are calculated at the midpoint of a control volume face by using relations adapted to the computations on a strongly stretched grid in the boundary layer.
    Computational Mathematics and Mathematical Physics 06/2008; 48(7):1181-1202. · 0.41 Impact Factor
  • K. N. Volkov
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    ABSTRACT: The motion and heat and mass transfer of particles of a disperse admixture in nonisothermal jets of a gas and a low-temperature plasma are simulated with allowance for the migration mechanism of particle motion actuated by the turbophoresis force and the influence of turbulent fluctuations of the jet flow velocity on heat and mass transfer of the particle. The temperature distribution inside the particle at each time step is found by solving the equation of unsteady heat conduction. The laws of scattering of the admixture and the laws of melting and evaporation of an individual particle are studied, depending on the injection velocity and on the method of particle insertion into the jet flow. The calculated results are compared with data obtained with ignored influence of turbulent fluctuations on the motion and heat and mass transfer of the disperse phase.
    Journal of Applied Mechanics and Technical Physics 01/2008; 49(3):425-436. · 0.25 Impact Factor
  • K. N. Volkov, V. N. Emel'Yanov
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    ABSTRACT: Turbulent flows in channels with intense distributed injection are modeled using the large eddy method and the two-equation k-ɛ turbulence model. The calculations are carried out for different velocities of injection from the channel walls. For a channel with one-sided injection the results of large eddy simulation are in good agreement with the measured data, whereas the calculations in accordance with the k-ɛ model give a less convex cross-sectional velocity profile and an appreciable error in determining the surface friction coefficient on the impermeable wall and also have certain other shortcomings. In the case of two-sided injection, the results of the calculations by the large eddy method and the k-ɛ model are in good agreement with one another and the data of physical experiments.
    Fluid Dynamics 01/2008; 43:573-582. · 0.31 Impact Factor
  • K. N. Volkov
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    ABSTRACT: This paper considers the influence of the mass flow of the gas ingested from the cavity formed by the rotor-to-stator clearance on the formation and structure of secondary flows in the blade passage of the gas-turbine stage. The flow is described by the Reynolds-averaged Navier-Stokes equations, to close which the Spalart-Allmaras model and the k-ε model of turbulence with corrections for the rotation and curvature of the streamlines are used. Comparison of the results of the numerical simulation obtained from the point of view of different turbulence models is made.
    Journal of Engineering Physics and Thermophysics 01/2008; 81(4):748-759.
  • K. N. Volkov
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    ABSTRACT: A simulation of the flow in a jet has been carried out with the use of the Reynolds-averaged, space-filtered Navier-Stokes equations closed by the k-ε model of turbulence and the subgrid RNG model of eddy viscosity. The results of calculations carried out on the basis of the k-ε model and the results of simulation of large vortices are in quantitative and qualitative agreement with the corresponding measurement data, which is evidence in favor of the main laws defining the decay of the gas-dynamic behavior of cold-gas submerged jets and the fluctuations of their parameters.
    Journal of Engineering Physics and Thermophysics 01/2008; 81(2):332-341.
  • K. N. Volkov
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    ABSTRACT: Large eddy simulation is performed of a subsonic nonisothermal turbulent jet flowing out from a round nozzle into submerged space. The Navier-Stokes equations filtered over space and the RNG model of subgrid-scale viscosity are used for describing the flow. The calculations are performed for different values of the degree of jet preheating. The processing of the results of numerical simulation enables one to obtain the distributions of correlation moments of fluctuations of density, velocity, and temperature along the axis and in cross sections of jet flow. The calculation results are compared with the available data obtained using the solution of Reynolds-averaged Navier-Stokes equations and equations of the k-ɛ model of turbulence, as well as with the data of physical experiment.
    High Temperature 01/2008; 46(5):630-638. · 0.49 Impact Factor
  • K. N. Volkov
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    ABSTRACT: The total-pressure loss in gas turbines is evaluated. Reynolds-averaged Navier-Stokes equations are used for numerical calculations. The Spalart-Allmaras model, the k-ε model, and the two-layer model and their different modifications allowing for the rotation of the flow and the curvature of streamlines are used to close these equations. The role of different corrections to the turbulence models for the accuracy of calculated estimates is elucidated.
    Journal of Engineering Physics and Thermophysics 09/2007; 80(5):903-911.
  • K. N. Volkov
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    ABSTRACT: This paper considers issues connected with the construction and numerical realization of stochastic models of motion and scattering of condensed impurity particles in a turbulent flow based on the integration of a Langevin-type equation. The proposed model is used to calculate the turbulent flow of a low-concentration gas suspension in a channel with permeable walls. Calculations are performed for various values of the injection rate, sizes of particles, and the conditions of their introduction into the channel.
    Journal of Engineering Physics and Thermophysics 04/2007; 80(3):570-582.

Publication Stats

23 Citations
5.50 Total Impact Points

Institutions

  • 2010–2013
    • Kingston University London
      Londinium, England, United Kingdom
  • 2005–2011
    • University of Surrey
      Guilford, England, United Kingdom
  • 2005–2007
    • Baltic State Technical University
      Sankt-Peterburg, St.-Petersburg, Russia