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Thermophysics and Aeromechanics

2009 year, number 1

1.
Estimation of energetic efficiency of heat supply in front of the aircraft at supersonic accelerated flight. Part II. Mathematical model of the trajectory boost part and computational results

A.F. Latypov
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: free stream heating, planning flight, efficiency, scramjet, exergy method, optimal trajectory
Pages: 1-12

Abstract >>
The fuel economy was estimated at boost trajectory of aerospace plane during energy supply to the free stream. Initial and final velocities of the flight were given. A model of planning flight above cold air in infinite isobaric thermal wake was used. The comparison of fuel consumption was done at optimal trajectories. The calculations were done using a combined power plant consisting of ramjet and liquid-propellant engine. An exergy model was constructed in the first part of the paper for estimating the ramjet thrust and specific impulse. To estimate the aerodynamic drag of aircraft a quadratic dependence on aerodynamic lift is used. The energy for flow heating is obtained at the sacrifice of an equivalent decrease of exergy of combustion products. The dependencies are obtained for increasing the range coefficient of cruise flight at different Mach numbers. In the second part of the paper, a mathematical model is presented for the boost part of the flight trajectory of the flying vehicle and computational results for reducing the fuel expenses at the boost trajectory at a given value of the energy supplied in front of the aircraft.



2.
Analysis of supersonic flow around two bodies of revolution near a surface

E.K. Derunov1, V.F. Volkov2, A.A. Zheltovodov3, A.I. Maksimov4
1 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
2 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
3 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia, zhelt@itam.nsc.ru
4 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: shock waves, turbulent boundary layer, viscous-inviscid interaction, separated zones, flow topology, aerodynamic interference, Euler equations
Pages: 13-36

Abstract >>
The results of experimental and numerical investigations of the peculiarities of flow around two identical cylindrical bodies of revolution of diameter D = 50 mm and the body aspect ratio λ = 5 with conical forebodies whose apex angles are θ = 40° and 60°, which are located above a horizontal surface in parallel with one another and with the flow, are presented for the Mach numbers М = 4.03, Reynolds numbers Re1 ≈ 55⋅106 m−1, fixed distance from the surface Y = Δy/D = 0.96, and the gaps between their axes Z = Δz/D = 1.06−2.4. The peculiarities of three-dimensional turbulent separated flows realizing on the bodies and on the plate as well as the possibilities of predicting the aerodynamic forces and moments acting on the bodies on the basis of numerical computations within the framework of the Euler equations are considered.



3.
Influence of small angles of attack and sweep on the rolling moment at a hypersonic flow around the bodies of revolution

YU.A. Mokin
State Rocket Center Makeyev Construction Bureau, Miass, Russia, src@makeyev.ru
Keywords: hypersonic flow, body of revolution, small variations of surface, angle of attack, rolling moment
Pages: 37-42

Abstract >>
The influence of small attack and sweep angles on the rolling moment variation at a supersonic flow around the bodies close to the bodies of revolution is considered. Based on the method of the differential hypothesis of locality the integral expressions are obtained for the derivatives of the rolling moment coefficient with respect to the attack and sweep angles. The norm of these derivatives is defined and the estimates for the norm are obtained.



4.
Deformation of viscoelastic coating in a turbulent flow

V.M. Kulik
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia, kulik@itp.nsc.ru
Keywords: compliant coating, turbulent flow, pressure pulsations, 2D model of deformation, energy dissipation, Reynolds stresses
Pages: 43-56

Abstract >>
The rate and amplitude of compliant coating deformation by turbulent pressure pulsations were calculated. Complex compliance determined by a 2D model has two components: along and across the coating. Dependence of the components of dimensionless compliance on the wavelength ⎯ coating thickness ratio was determined for 0.3 < λ/H < 30 and dependence of these components on the ratio of flow velocity to velocity of wave propagation was determined for 0.1 < V/C < 10.
Deformation amplitude and rate of surface displacement for the hard compliant coatings which can be used in practice were calculated within the range of 5-55 m/s for the water and air turbulent flow. The effects of the loss tangent and Poisson's ratio of the coating material were also studied.
It is shown that the mean-square displacement of their surface does not exceed the thickness of a viscous sublayer. However, the velocity of surface motion is comparable with velocity pulsations in a boundary layer near a wall. This can be a reason for drag reduction on a compliant wall. The calculated value of ratio between energy absorbed by the wall and energy dissipated within the flow because of drag was 10−4 for water and 10−6 for air. This estimate does not confirm the hypothesis explaining drag reduction by energy takeoff from the flow.



5.
Spatial structure of the flow at round jet outflow into a narrow channel

B.V. Perepelitsa1, M.V. Shestakov2
1 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia, perep@itp.nsc.ru
2 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: visualization, turbulence, jet, narrow channel, vortex structures
Pages: 57-60

Abstract >>
Results on visual studies of the flow structure in case of the round submerged jet in a narrow channel are presented. These studies were carried out for the laminar and turbulent flows. The typical large-scale structures and zones of intensive turbulent mixing were identified in the flow.



6.
Numerical solution of a stationary nonisothermal two-phase filtration problem by the steadying method

O.B. Bocharov1, I.G. Telegin2
1 Institute for Water and Environmental Problems SB RAS, Novosibirsk, Russia
2 Scientific, Research, and Design Institute "KogalymNIPINeft", Tyumen, Russia, igtelegin@yandex.ru
Keywords: nonstatioanry nonisothermal filtration, stationary solutions, asymptotic behavior of solutions, nonisothermal filtration
Pages: 61-67

Abstract >>
The structure of solutions of a stationary nonisothermal problem of the two-phase filtration of immiscible fluids is studied numerically. The character of the convergence of nonstationary solutions to stationary ones is investigated. It is shown that at different parameter values the solution may have an interval, where s(x) ≡ 0 or s(x) ≡ 1. The temperature effect on the structure of the solutions of the equation for water saturation is investigated.



7.
The effect of wave characteristics on rivulet formation in heated liquid films

E.A. Chinnov
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia, chinnov@itp.nsc.ru
Keywords: rivulet formation, thermocapillarity, film, waves
Pages: 69-77

Abstract >>
Formation of rivulets on the surface of non-isothermal water film falling vertically over the heaters with different sizes and boundary conditions was studied experimentally. The distances between rivulets were measured depending on Reynolds number, heat flux density and film path (a distance between the lower edge of a film-former nozzle and the measurement point of film flow characteristics). The breakdown of solitary waves at liquid film heating was revealed. Four zones of film path influence on rivulet formation were distinguished.



8.
Modelling of the sedimentation of polydisperse suspension particles in a plate centrifuge

L.L. Minkov1, E.V. Pikushchak2, J.G. Dueck3
1 Tomsk State University, Tomsk, Russia
2 Tomsk State University, Tomsk, Russia, Pikushchak@ftf.tsu.ru
3 Erlangen-Nurnberg University, Erlangen, Germany
Keywords: sedimentation, dense polydisperse suspension, plate centrifuge, particle interaction, numerical simulation
Pages: 79-88

Abstract >>
The investigation of the sedimentation of particles of a dense polydisperse suspension in the plate centrifuge was carried out based on numerical simulation. It was shown that the reason for the nonmonotone behavior of the sedimentation velocity dependence on particle size is the action of different mechanisms of the particles interaction. The appropriateness of the formula  for measuring the sedimentation velocity of particles of a dense polydisperse suspension in the plate centrifuge was examined.



9.
Solution and hydrate formation behind a shock wave in liquid with nitrogen - carbon dioxide bubbles in a presence of surfactant

V.E. Dontsov
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia, dontsov@itp.nsc.ru
Keywords: shock wave, liquid, gas bubbles, bubble fragmentation, solution, hydrate formation, surfactant
Pages: 89-101

Abstract >>
The processes of solution and hydrate formation behind a shock wave of moderate amplitude were studied experimentally in water with bubbles of nitrogen - carbon dioxide mixture at different initial static pressures in the medium and surfactant concentrations. It is shown that these bubbles do not affect significantly the processes of solution and hydrate formation behind a shock wave during the considered periods. The hypothesis about partial hydration of nitrogen from the gas mixture at intense formation of carbon dioxide hydrate was suggested for the conditions, when the pressure behind the wave is less than the equilibrium pressure of nitrogen hydrate formation at a given temperature.



10.
Conditions for growth of columnar and filamentary crystals

A.A. Bochkarev1, V.I. Polyakova2
1 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia, aboch@online.nsk.su
Keywords: sorption, nucleation, condensation, growth of columnar crystals
Pages: 103-114

Abstract >>
The computer model of the initial stage of condensation processes is developed. The stochastic processes of adsorption, surface diffusion, and desorption occur on the 70×70 lattice of adsorption vacancies. The model was tested by an example close to water vapor sorption on a conventional crystal surface. Computed results demonstrate the processes of nucleation, growth of crystals, and developed condensation. Computations were carried out for various adsorption energies. Results showed that with decreasing energy of adsorption the character and rate of nucleation and subsequent condensation vary. With decreasing energy of adsorption the probability of nucleation of islets on substrate reduces, the filling of the next atomic layers on islets occurs earlier than the filling of the substrate, the growth rate of islets in height increases as compared to condensation of a continuous film, and the growth rate of area of islets decreases. There is a typical energy of adsorption at which the growth rate of islets in height reaches its maximum. At a further drop of adsorption energy, there is a growth of islets only in height, the growth rate, however, reduces. The phenomena revealed in computations illustrate the mechanism of origin of columnar and filamentary crystals.



11.
Dependence of the critical heat flux at boiling on the coolant physical properties

I.I. Gogonin
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia, gogonin@itp.nsc.ru
Keywords: boiling, critical heat flux, physical properties of the coolant
Pages: 115-122

Abstract >>
It has been experimentally proved that heat transfer at boiling appears to be the problem with the conjugated boundary conditions. Heat transfer and critical heat fluxes at boiling depend both on physical properties of the boiling liquid and on the number of characteristics of the heat transferring wall.
Various experimental data of the problem of boiling liquid with various physical properties have been analysed. To eliminate or minimize influence of the properties of the cooled wall on the value of critical heat transfer, the data obtained at boiling on the thick cooled wall only from the stainless steel or nichrome are considered. To eliminate effect of capillary forces specific linear size of heat transferring wall satisfied the condition



12.
Mathematical modelling of complex heat transfer in a rectangular enclosure

G.V. Kuznetsov1, M.A. Sheremet2
1 Tomsk Polytechnic University, Tomsk, Russia
2 Tomsk State University, Tomsk, Russia, Michael-sher@yandex.ru
Keywords: conjugate heat transfer, natural convection, radiation, thermal conductivity, enclosure, Boussinesq approximation, Rosseland approximation
Pages: 123-133

Abstract >>
Numerical simulation of convective-radiative heat transfer in an enclosure with a heat source in the presence of heat-conducting walls of the finite thickness was carried out. The distributions of both local (streamlines, temperature fields) and integral (mean Nusselt numbers at typical interfaces) characteristics describing specific features of the investigated process in a real range of the variation of determining parameters were obtained. The radiation influence scales at thermal modes formation were determined. The effect of transient factor on the fields development of both hydrodynamic and thermodynamic characteristics was analysed. Correlation ratios for determining the mean Nusselt number at solid-gas interfaces were obtained depending on the Grashof number.



13.
Determination of spacecraft orientation by the temperature field analysis of its outer surface

N.P. Semena
Space Research Institute RAS, Moscow, Russia, semena@hea.iki.rssi.ru
Keywords: spacecraft orientation, spacecraft thermal mode, thermodynamic system of orientation
Pages: 135-147

Abstract >>
It was demonstrated that by analysing temperature field of the outer surface of the spacecraft it is possible to determine its orientation - directions to the principal heat sources within the Solar system, including the Sun and the nearest planets. For the spacecraft with the simplest configuration, this problem can be solved analytically. In the real spacecraft there shall be simple heat-sensitive elements with weak thermal bond with the spacecraft and high sensitivity to the changing outer thermal conditions. The experiment has proved that the accuracy of orientation determination with the use of such temperature measurement reaches 5 ang. min at the rotation velocity of the spacecraft up to 30 ang. deg /min.



14.
Numerical investigation of the influence of period duration on evolution of intense wave of the second sound

L.P. Kondaurova1, S.K. Nemirovsky2
1 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia, theory@itp.nsc.ru
Keywords: superfluidity, heat transfer, intensity, duration
Pages: 149-157

Abstract >>
The effect of repetition time of powerful rectangular pulses on their dynamics was studied numerically on the basis of hydrodynamics of superfluid turbulence. The plane, cylindrical, and spherical situations are considered. Calculations were carried out without mass transfer (the second sound), which corresponded to experimental conditions. Numerical results are compared qualitatively with experimental data.



15.
Study of plasma technology for silicate refractory melts production

A.A. Nikiforov1, E.A. Maslov2, N.K. Skripnikova3, O.G. Volokitin4
1 Tomsk State University for Design and Construction, Tomsk, Russia
2 Tomsk State University for Design and Construction, Tomsk, Russia, maslov_eugene@mail.ru
3 Tomsk State University for Design and Construction, Tomsk, Russia
4 Tomsk State University for Design and Construction, Tomsk, Russia
Keywords: plasma unit, silicate refractory melt, high-concentrated heat sources, homogenizer, numerical study, skull layer
Pages: 159-163

Abstract >>
Herein the fundamentally new unit for production of silicate refractory melts with the use of high-concentrated heat fluxes is considered. Mathematical model describing temperature fields in skull layer in the process of the plasma flow interaction with the particles of refractory silicate material has been developed. Typical numerical results of temperature distribution in various sections of the skull layer are presented. Numerical and experimental data have been compared, and their fair agreement is obtained.



16.
Numerical modelling of heat transfer in plasma shaft electric furnace at utilization of anthropogenic waste

A.I. Aliferov1, A.S. Anshakov2, V.A. Sinitsyn3
1 Novosibirsk State Technical University, Novosibirsk, Russia, beam@itp.nsc.ru
2 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
3 Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: heat transfer, radiation, anthropogenic wastes, plasma electric furnace
Pages: 165-171

Abstract >>
The mathematical model of heat transfer between the counter flows of gas and porous batch  of anthropogenic wastes in the working area of a shaft furnace is presented. This model considers chemical transformations in separate batch components and radiation heat transfer between the gas and solid phases. Results of calculations are presented.