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Thermophysics and Aeromechanics

2018 year, number 4

1.

Turbulent structure in supersonic jets with a high Reynolds number

.V. Sobolev, V.I. Zapryagaev, N.P. Kiselev, D.A. Gubanov, and S.G. Kundasev


Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia

E-mail: sobolev@itam.nsc.ru


Keywords: skewed nozzle, brake jet, supersonic core, dynamic pressure, turbulence intensity, turbulence power spectrum
Pages: 473481
Abstract >>

The turbulent properties of a supersonic jet were studied related to a high level of pressure pulsation found in model jets of a reentry flight vehicle approaching the landing ground. This study comprised measurements of total pressure at a small-size target using a dynamic pressure probe placed in a free jet. The most comprehensive data about jet turbulence can be obtained by direct transformation of the pressure reading at the stagnation point near the target into the normalized velocity. The oscillogram of normalized velocity produces the velocity average value, root-mean-square value as well as turbulence intensity and turbulence spectrum. It was demonstrated that a high level of turbulence for a high-head jet retains along the supersonic core length and at the beginning of subsonic interval.

																								



2.

Influence of blunt-cone tip temperature on the laminar-turbulent transition in hypersonic boundary layers

D.A. Bountin, Yu.V. Gromyko, S.V. Kirilovskiy b, A.A. Maslov a, and T.V. Poplavskaya c


Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia

E-mail: maslov@itam.nsc.ru a, kirilov@itam.nsc.ru b, popla@itam.nsc.ru c


Keywords: hypersonic flow, stability, heat fluxes, laminar-turbulent transition, blunt cones, local heating/cooling, Transition SST model
Pages: 483496
																								



3.

Computational study of the laminar to turbulent transition over the SD7003 airfoil in ground effect

Eb. Kadivar1 and Er. Kadivar2


1University of Duisburg-Essen, Duisburg, Germany

2Shiraz University of Technology, Shiraz, Iran

E-mail: ebrahim.kadivar@uni-due.de


Keywords: laminar to turbulent transition, laminar separation bubbles, low Reynolds number, ground effect
Pages: 497505
Abstract >>

In this work, we present a numerical study of the laminar-turbulence transition flow around a symmetrical airfoil at a low Reynolds number in free flow and near the ground surface at different angles of attack. Finite volume method is employed to solve the unsteady Reynolds-averaged NavierStokes (RANS) equation. In this way, the Transition SST turbulence model is used for modeling the flow turbulence. Flow around the symmetrical airfoil SD7003 is numerically simulated in free stream and near the ground surface. Our numerical method can detect different aspects of flow such as adverse pressure gradient, laminar separation bubble and laminar to turbulent transition onset and the numerical results are in good agreement with the experimental data.

																								



4.

TVC effects on flow separation on slender cylinders

A. Mehmood and M. Usman


International Islamic University, Islamabad, Pakistan

E-mail: usman725.iiui@gmail.com


Keywords: TVC, non-similar flow, slender cylinders, flow separation, power-law shaped bodies
Pages: 507513
Abstract >>

Occurrence of flow separation within the boundary-layer is primarily attributed to the growth of adverse pressure gradient within the boundary-layer. Such a separating boundary-layer can, however, be made to stay attached to the bounding surface due to various remedies where the surface transverse curvature (TVC) is one of them while the body contour is another. Assistive role of the surface transverse curvature is utilized in delaying the boundary-layer separation in a retarded flow past the slender bodies by assuming different body configurations. Axially-symmetric bodies of revolution of different shapes having a varying cross section in x, following the power-law form, have been considered in this study. It is shown that the point of separation is strongly dependent upon the surface curvature parameter k and the body-shape index n, which in fact control the flow separation. This fact ensures that an increase in the surface curvature parameter k and the body-shape index n leads to an increase in the wall shear stress which consequently delays the flow separation. Significant delay in flow separation is observed on cylinders having sufficiently large transverse curvature. Percent increase in the separation length corresponding to various values of the curvature parameter and the body-shape index has been calculated and reported in the form of Tables.

																								



5.

Drag reduction by compliant coatings made of a homogeneous material

V.M. Kulik1, A.V. Boiko2, and I. Lee3


1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia

2Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia

3Pusan National University, Pusan, South Korea

E-mail: vkulik@itp.nsc.ru


Keywords: compliant coating, turbulence control, drag reduction, dynamic compliance
Pages: 515524
Abstract >>

The possibility of drag reduction due to compliant coatings of viscoelastic silicone rubbers has been tested experimentally. For this purpose, a series of single-layer coatings of various thicknesses was made of a homogeneous material. The experiments were carried out in a high-speed cavitation tunnel of Pusan National University. Dynamic viscoelastic properties of coating materials were carefully measured. The range of flow rates and coating thicknesses was calculated assuming that the coatings can interact intensively with the dynamic structures of the turbulent boundary layer only in the region of frequencies of their maximum compliance. The predicted range of coating parameters and flow velocities, in which the coatings reduce drag, is compared with experimental data.

																								



6.

Numerical investigation of the two-dimensional natural convection inside the system based on phase change material with a source of volumetric heat generation

N.S. Bondareva and M.A. Sheremeta


Tomsk State University, Tomsk, Russia

E-mail: Michael-sher@yandex.rua


Keywords: melting, natural convection, thermal conductivity, paraffin, energy source with a con-stant heat generation, laminar regime, numerical modeling
Pages: 525537
Abstract >>

The work is devoted to the numerical investigation of unsteady regimes of the paraffin convective melting inside a closed rectangular region heated from the energy source with a constant density of the volumetric heat generation. The problem has been formulated in dimensionless transformed variables stream function-vorticity-temperature and solved by using a finite difference method. The main characteristics of the melting process and heat transfer in a liquid medium have been obtained and analyzed at different powers of the energy source (from 5 to 100 Watt). The influence of heat transfer from the source on the temperature distributions inside the region containing paraffin has been analyzed.

																								



7.

Determining the temperature of an opaque object by its thermal radiation spectrum: forms of initial data presentation and methods

S.P. Rusin


Joint Institute for High Temperatures of RAS, Moscow, Russia

E-mail: sprusin@yandex.ru


Keywords: true temperature, emissivity, thermal radiation spectrum
Pages: 539554
Abstract >>

Spectral distributions of intensities, relative emissivity, and inverse radiance temperatures of an opaque, free- radiating object in a condensed state are used as the initial data. The methods of determining the thermodynamic (true) temperature corresponding to these distributions, when object emissivity is previously unknown, are considered. The advantages and disadvantages of each method and corresponding form of an initial data presentation are discussed. It is shown that the spectral distribution of inverse radiance temperatures gives the greatest information about the true temperature and emissivity of the measured object. The estimates of the temperature range to which the true temperature belongs are given based on the known experimental data for tungsten. The methods for additional verification of reliability of the obtained results are presented.

																								



8.

Analysis of the influence of radiation polarization type on the absorptive capacity and propulsive motion of microparticles in the light field of 2 laser

O.B. Kovalev


Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia

E-mail: kovalev@itam.nsc.ru


Keywords: laser radiation, polarization, absorption, metal particle, vapor recoil pressure, light-propulsive force
Pages: 555563
Abstract >>
The influence of the linear and circular polarization of laser radiation on the absorption coefficient of single spherical AISI-304 steel particles was theoretically analyzed. It is shown that the absorbed power of the laser beam depends on the particle sizes and on the location of particles in the light field. The influence of the laser-induced evaporation of the material on the regularities of the reactive motion of particles at a power density in the beam exceeding some threshold value is established. The direction of the action of the reactive force is directly related to the non-uniform distribution of the absorbed laser-emitted power and with the recoil pressure of the vapors moving away from the curvilinear surface of particle. A description to the mechanism of deflection of the particles reactive force vector due to the vapor recoil pressure in the light field of a Gaussian beam from the direction of the beam action is given.
																								



9.

The simple fundamental equation of state for liquid, gas, and fluid of xenon

A.B. Kaplun, A.B. Meshalkin, and O.S. Dutova


Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia

E-mail: kaplun@itp.nsc.ru


Keywords: fundamental equation, compressibility factor, temperature, pressure, density, enthal-py, heat capacity, speed of sound
Pages: 565574
Abstract >>

To describe the thermodynamic properties of xenon, a new fundamental low-parametric equation of state (in the form of reduced Helmholtz energy) is obtained with the help of the methods and approaches developed by the authors. It allows us to describe the thermal properties of gas, liquid, and fluid with a sufficiently high accuracy close to the accuracy of experiment in a range from the density in the ideal gas state to the density at the triple point, excluding the critical region. The caloric properties and speed of xenon sound are calculated without involving any caloric data, with the exception of ideal gas enthalpy. The values of isobaric heat capacity, sound speed, and other thermodynamic properties obtained by calculations are in good agreement with the experimental data.

																								



10.

Self-similar patterns of subsatellites formation at the capillary breakup of viscous jets

A.L. Grigoriev1, A.A. Koroteev2 a, A.A. Safronov1, and N.I. Filatov1


1The State Scientific Centre Keldysh Research Center, Moscow, Russia

2Moscow Aviation Institute, Moscow, Russia

E-mail: chkt@yandex.ru a


Keywords: subsatellites, capillary breakup, low-potential heat loss
Pages: 575585
Abstract >>

Formation of subsatellites at the capillary breakup of viscous liquid jets has been studied. The proposed analytical model qualitatively describes subsatellites formation. The obtained patterns for the formation of subsatellites nuclei and dynamics of their separation from a jet well agree with the results of numerical modeling.

																								



11.

Peculiarities of the hydraulic fracture propagation caused by pumping of proppant-fluid slurry

P.V. Karnakov, D.S. Kuranakov, V.N. Lapin, S.G. Cherny, and D.V. Esipov


Institute of Computational Technologies SB RAS, Novosibirsk, Russia

E-mail: cher@ict.nsc.ru


Keywords: growth of hydraulic fracture, proppant slurry flow, fluid filtration through a proppant pack, well production
Pages: 587603
Abstract >>

A new numerical model for hydraulic fracturing has been developed. This model takes into account several simultaneous processes: pumping of proppant-laden slurry and its flow through the fracture, fracture growth with variable height and length, proppant settling, forming of proppant packing, and fluid filtration through this packing. Simulation experiments demonstrated that proppant particle diameter has significant influence on forming the proppant packing, fluid filtration through the packing, and, finally, on the fracture length and ultimate distribution of fracture width.

																								



12.

Testing of solid fuel ramjet with measurement of thrust characteristics in aerodynamic facilities

D.A. Vnuchkov1, V.I. Zvegintsev1, D.G. Nalivaichenko1, V.I. Smolyaga2, and A.V. Stepanov2


1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia

2NPO SPLAV R&P Association, Tula, Russia

E-mail: vnuchkov@itam.nsc.ru


Keywords: ramjet, multi wedges air intake, solid fuel combustion, aerodynamic facility, internal thrust, net excess thrust
Pages: 605611
Abstract >>

A design of an axisymmetric solid fuel ramjet consisting of a multi wedges nose air intake, solid fuel gas generator, combustion chamber, and a nozzle, was developed. According to this design, a ramjet model for tests in the ground wind-tunnel facilities was fabricated. Experiments with solid fuel combustion were carried out in the Transit-M and T-313 wind tunnels, ITAM SB RAS, at air-flow Mach numbers = 2.5-5.0. High values of the internal and net excess thrust were obtained.

																								



13.

Influence of process parameters on thermodynamic efficiency of expander-generator units at the plants for technological decompression of transported natural gas

A.V. Klimenko, V.S. Agababov a, P.N. Borisova, S.N. Petin, and A.V. Koryagin


Moscow Energy Institute, Moscow, Russia

E-mail: agababovvs@yandex.ru a


Keywords: transported gas, pressure reduction/decompression, throttling, expander-generator units, thermodynamic efficiency, exergy efficiency, influence of process parameters
Pages: 613622
Abstract >>

The article presents the research results of the influence of process parameters on the thermodynamic efficiency of expander-generator units, used as an alternative to throttling devices for technological reduction of pressure of transported natural gas at the plants of technological decompression of the gas supply system gas distribution stations (GDS) and gas control points (GCP). The process parameters are the temperature of the outside air, the ratio between the pressures of the transported gas at the outlet and inlet of GDS and GCP, and the temperature of the gas heating before the expander. Various circuit designs of expander-generator units for generating either only electricity or electricity and cold are considered. Exergy efficiency is taken as a criterion for evaluating thermodynamic efficiency. The calculation results for the changes in flow exergy and exergy efficiency at changing process parameters are presented in graphical form. The thermodynamic efficiencies of throttling devices and expander-generator units are compared. It is shown that the replacement of the throttling device by the expander-generator unit for all the considered process parameters leads to an increase in the exergy efficiency of the stations for technological decompression of the transported gas in all the considered schemes of this unit inclusion: without heating the gas in the expander-generator unit, with heating the gas after the expander, as well as with heating before and after it.

																								



14.

Intensification of aeration and mass transfer in wastewater treatment by discrete-pulse energy input

A.A. Dolinskiy, A.N. Obodovich, and V.V. Sydorenko


Institute of Engineering Thermophysics NASU, Kiev, Ukraine

E-mail: tdsittf@ukr.net


Keywords: wastewater, biological treatment, aerator-oxidizer, pulsation frequency, DPEI, flow shear rate
Pages: 623630
Abstract >>
The article focuses on the application of thermophysics in environmental protection, namely the wastewater treatment due to mass transfer enhancement and acceleration of the reaction of biological oxidation. Intensification results from the effect of the discrete-pulse energy input (DPEI) method on the treated medium (wastewater). The method is implemented by means of a new heat-and-mass equipment, namely, an aerator-oxidizer of rotor type.
																								



15.

Mathematical model for axisymmetric steady flow within layered structures with finite or infinitely high bulk viscosity

S.M. Aulchenko1, 2, E.S. Vyachkin3, E.A. Vyachkina3, and V.O. Kaledin3


1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia

2Novosibirsk State University of Architecture and Civil Engineering (SIBSTRIN), Novosibirsk, Russia

3Novokuznetsk Institute (Affiliation) of the Kemerovo State University, Novokuznetsk, Russia

E-mail: aulchsm@mail.ru


Keywords: , , ,
Pages: 631634
Abstract >>

A mathematical model was developed for viscous incompressible medium; this model comprises a small parameter for regularization of ill-posed problem. Starting from the analogy with strain problems of axisymmetric laminar structures which include the elastic orthotropic and elastic volume-incompressible layers with a connection to viscous laminar fluid flow, we have developed a method providing a single algorithm for computation of velocity field, stresses, and other parameters of laminar composite material. The example of calculation for the binding agent flow during pultrusion formation is presented.

																								



16.

Equations for describing a family of self-similar solutions of the far field of a round submerged jet

R.I. Mullyadzhanov


Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia

Novosibirsk State University, Novosibirsk, Russia

E-mail: rustammul@gmail.com


Keywords: turbulence, self-similarity, submerged jet, far field
Pages: 635838
Abstract >>

The flow of a turbulent round submerged jet in far field has been considered. The modified Navier-Stokes equations have been derived with the aid of known self-similar properties of the time-mean flow as well as the spatial and temporal characteristics of the entire spectrum of the scales of turbulent fluctuations. A technique has been proposed for the numerical computation of these equations to describe a family of self-similar solutions in a cylindrical region with periodic boundary conditions in the longitudinal direction, and the velocity of the jet expansion enters the obtained equations explicitly as a parameter.

																								



17.

Enthalpy and heat capacity of the intermetallic compound CsBi2 in the solid and liquid states

S.V. Stankus, I.V. Savchenko, O.S. Yatsuk, and Yu.M. Kozlovskii


Kutateladze Institute of Thermophysics, Novosibrisk, Russia

E-mail: stankus@itp.nsc.ru


Keywords: cesium-bismuth system, solid and liquid states, enthalpy, heat capacity, isoperibolic drop calorimeter
Pages: 639642
Abstract >>

Enthalpy of solid and liquid intermetallic compound CsBi2 in the temperature range of 4301225 K was measured by massive isothermal drop calorimeter. Approximation equations were obtained, and isobaric heat capacity and enthalpy change on melting were determined. The tables of recommended values of caloric properties in the range from 298.15 K to 1225 K were developed. The experimental uncertainty of enthalpy and heat capacity measurements were estimated to be within 0.35 and 1.0%, respectively. The obtained results were compared with the calculations according to the laws of ideal solutions.