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Thermophysics and Aeromechanics

2016 year, number 2

Development and testing of a numerical simulation method for thermally none-quilibrium dissociating flows in ANSYS Fluent

G.V. Shoev1,2,3, Ye.A. Bondar1,2, G.P. Oblapenko3, and E.V. Kustova3
1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3St.-Petersburg University, St. Petersburg, Russia
Keywords: numerical simulation, thermal nonequilibrium, dissociation, vibrational relaxation, shock waves, real gas effects
Pages: 151163

Abstract >>
Various issues of numerical simulation of supersonic gas flows with allowance for thermochemical nonequilibrium on the basis of fluid dynamic equations in the two-temperature approximation are discussed. The computational tool for modeling flows with thermochemical nonequilibrium is the commercial software package ANSYS Fluent with an additional user-defined open-code module. A comparative analysis of results obtained by various models of vibration-dissociation coupling in binary gas mixtures of nitrogen and oxygen is performed. Results of numerical simulations are compared with available experimental data. 

DOI: 10.1134/S0869864316020013

Effect of VGs on a turbulent hydrogen jet

M. Senouci1, H. Hibbo2, B. Hammoudi1, M. Kadi1, and  B. Imine1
1University of Science and Technology of Oran Mohamed Boudiaf, El Mnaouer, Oran, Algeria
2University of Aleppo, Aleppo, Syria
Keywords: hydrogen jet, tip vortex, variable density, co-flowing, turbulent, slightly confined
Pages: 165171

Abstract >>
The aim of this study is to investigate numerically the effects of four vortices on the dynamic, scalar, and turbulent fields of the hydrogen jet. These vortices, which appear in the vicinities of the nozzle, are created by the vortex generators (VGs), and they are assembled with periodicity or symmetry in order, respectively, to give four vortices of the same or opposite direction. A second-order Reynolds stress model is used to investigate asymmetric turbulent jet. The results indicate that the presence of the vortex near the emission jet section noticeably enhances mixing to ensure a good combustion.

DOI: 10.1134/S0869864316020025

Numerical simulations of shock-wave interaction with a boundary layer in the plane supersonic flows with jet injection

A.O. Beketaeva, Ye.S. Moisseyeva, and A.Zh. Naimanova
Institute of Mathematics and Mathematical Modeling, Almaty, Kazakhstan
Keywords: supersonic flow, perfect gas, boundary layer, NavierStokes equations, shock wave
Pages: 173183

Abstract >>
A supersonic air flow in a plane channel with a transverse turbulent jet of hydrogen injected through a slot on the bottom wall is simulated. The algorithm for solving the Favre-averaged NavierStokes equations for the flow of a perfect multispecies gas on the basis of the WENO scheme is proposed. The main attention is paid to the interaction of the shock-wave structure with the boundary layers on the upper and lower duct walls under the conditions of an internal turbulent flow. Namely, a detailed study of the structure of the flow is done, and separation and mixing depending on the jet slot width are investigated. It is found that in addition to well-known shock-wave structures produced by the interaction of the free stream with the transverse jet and the bow shock interaction with the boundary layers near the walls, an additional system of shock waves and the flow separation arise on the bottom wall downstream at some distance from the jet. The comparison with the experimental data is performed.

DOI: 10.1134/S0869864316020037

Longitudinal control of aircraft dynamics based on optimization of PID parameters

S.N. Deepa and G. Sudha
Anna University, Regional Center, Coimbatore, Tamilnadu, India
Keywords: pitch control dynamics, PID controller, optimum parameters
Pages: 185194

Abstract >>
Recent years many flight control systems and industries are employing PID con-trollers to improve the dynamic behavior of the characteristics. In this paper, PID con-troller is developed to improve the stability and performance of general aviation aircraft system. Designing the optimum PID controller parameters for a pitch control aircraft is important in expanding the flight safety envelope. Mathematical model is developed to describe the longitudinal pitch control of an aircraft. The PID controller is designed based on the dynamic modeling of an aircraft system. Different tuning methods namely ZeiglerNichols method (ZN), Modified ZeiglerNichols method, TyreusLuyben tuning, AstromHagglund tuning methods are employed. The time domain specifications of different tuning methods are compared to obtain the optimum parameters value. The results prove that PID controller tuned by ZeiglerNichols for aircraft pitch control dynamics is better in stability and performance in all conditions. Future research work of obtaining optimum PID controller parameters using artificial intelligence techniques should be carried out.

DOI: 10.1134/S0869864316020049

Burning carbon monoxide in the settling chamber of a hotshot wind tunnel for obtaining the CO2 test gas

V.V. Shumskii1 and M.I. Yaroslavtsev1,2
1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
E-mail:, yaroslav@itam.nsc. ru
Keywords: hotshot wind tunnel, settling chamber, test gas, carbon monoxide, carbon dioxide
Pages: 195200

Abstract >>
A method of formation and heating of 2 as a test gas in the settling chamber of a hotshot wind tunnel is considered. To form and heat 2, the chamber is filled with a source gas mixture of , 2, and 2, and after initiation, these substances participate in an exothermic chemical reaction in accordance with the formula + 0.5 2 + 2 = (1 + )2. A stoichiometric ratio of the concentrations of carbon monoxide CO and oxygen is used. Variation of the number of moles x of ballast CO2 in the left part of the chemical formula allows changing the temperature of the resultant test gas in a wide range. Experiments in the IT-302M hotshot wind tunnel carried out at ITAM SB RAS have shown that a pressure increase during an isochoric process in the settling chamber due to the joint effect of heat released in the reaction + 0.5 2 and an electric charge provides the completeness of CO combustion almost equal to unity. The time of reaction completion at its initiation by an electric arc is no more than several milliseconds.

DOI: 10.1134/S0869864316020050

Determination of integral turbulence model parameters as applied to calculation of rod-bundle flows in porous-body approximation

M.N. Vlasov, A.S. Korsun, Yu.A. Maslov, I.G. Merinov, V.I. Rachkov, and V.S. Kharitonov
MEPhI National Research Nuclear University, Moscow, Russia
Keywords: porous-body model, anisotropy, integral model of turbulence, three-dimensional simulation, heat and mass transfer
Pages: 201209

Abstract >>
In the present paper, results of numerical simulation of single-phase flows of heat carrier through square and triangular rod bundles are reported. The simulations were aimed at the determination of parameters involved in an integral model of turbulence being developed for modeling nuclear-reactor cores and heat exchangers in anisotropic porous-body approximation.

DOI: 10.1134/S0869864316020062

Dynamics of a cavitation bubble near a solid wall

A.A. Aganin, M.A. Ilgamov, L.A. Kosolapova, and V.G. Malakhov
Institute of Mechanics and Engineering of Kazan Science Center RAS, Kazan, Russia
Keywords: cavitation bubble, potential fluid flow, method of boundary elements
Pages: 211220

Abstract >>

The cavitation bubble dynamics, the variation of pressure and velocity fields of the surrounding liquid in the process of the bubble axisymmetric compression near a planar solid wall are considered. It is assumed that the liquid is at rest at the initial moment of time, and the bubble has a spheroidal shape. The liquid is assumed inviscid and incompressible, its motion being potential. The bubble surface deformation and the liquid velocity on the surface are computed by the Euler scheme using the boundary element method until the moment of the collision of some parts of the bubble surface with one another. The influence of the distance of the bubble from the wall and its initial nonsphericity on the liquid pressure and velocity fields, the bubble shape, and the pressure inside the bubble at the end of the time interval under consideration are studied. The maximum pressure in liquid is shown to realize at the bottom of the cumulative jet arising at the bubble collapse with direction to the wall. In the upper part of this jet, the velocity and pressure are practically constant, and the pressure in the jet is approximately equal to the pressure in the bubble.

DOI: 10.1134/S0869864316020074

Evaporative cooling of air in an adiabatic channel with partially wetted zones

V.I. Terekhov1,2, M.V. Gorbachev2, and H.Q. Khafaji1,2
1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: direct evaporative cooling, heat and mass transfer, laminar flow, step boundary conditions, thermal and humid efficiency
Pages: 221230

Abstract >>
The paper deals with the numerical study of heat and mass transfer in the process of direct evaporation air cooling in the laminar flow of forced convection in a channel between two parallel insulated plates with alternating wet and dry zones along the length. The system of NavierStokes equations and equations of energy and steam diffusion are being solved in two-dimensional approximation. At the channel inlet, all thermal gas-dynamic parameters are constant over the cross section, and the channel walls are adiabatic. The studies were carried out with varying number of dry zones (n = 016), their relative length (s/l = 01) and Reynolds number Re = 501000 in the flow of dry air (j0 = 0) with a constant temperature at the inlet (T0 = 30 C). The main attention is paid to optimization analysis of evaporation cell characteristics. It is shown that an increase in the number of alternating steps leads to an increase in the parameters of thermal and humid efficiency. With an increase in Re number and a decrease in the extent of wet areas, the efficiency parameter reduces.

DOI: 10.1134/S0869864316020086

Thermocapillary deformation of a water layer at local heating

V.V. Cheverda1,4, A.A. Fedorets2, I.V. Marchuk1,3, and O.A. Kabov1,4
1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2Tyumen State University, Tyumen, Russia
3Novosibirsk State University, Novosibirsk, Russia
4Tomsk Polytechnic University, Tomsk, Russia
Keywords: liquid layer, local heating, thermocapillary deformation, thermocapillary convection
Pages: 231236

Abstract >>
A horizontal water layer of 0.29÷0.44 mm thickness, locally heated from the substrate, is investigated. The value of thermocapillary deformation occurring at local heating is measured by an inverted laser scanning confocal microscope Zeiss LSM 510 Meta. The heater in the form of strip of 0.5-mm width, 40-mm length, and 0.5-mm height made of indium oxide is sputtered on a sapphire substrate. The water temperature from the side of the substrate is measured using the infrared scanner Titanium 570M. We studied in detail the effect of the initial layer thickness and heating power on the value of thermocapillary deformation and temperature field. It is shown that defor-mation increases with an increase in thermal capacity and decrease in the layer thick-ness. Results of numerical simulation are in good qualitative agreement with the measurement results.

DOI: 10.1134/S0869864316020098

Study of temperature fields in a rectangular plate with a temperature-dependent internal source with the aid of fast expansions

A.D. Chernyshov1, V.V. Goryainov2, and A.N. Marchenko1
1Voronezh State University of Engineering Technologies, Voronezh, Russia
2Voronezh State University of Architecture and Civil Engineering, Voronezh, Russia
Keywords: analytic solution, temperature, variable internal source, rectangular shape, fast expansions
Pages: 237245

Abstract >>
The approximate analytic solution of the problem of temperature field in a rectangular plate with an internal temperature-dependent source is obtained by the method of fast expansions. The critical value of a parameter characterizing heat release, which fun-damentally affects the analytic solution form, is found. The maximum solution error is shown to amount to 0.02 at the consideration of the first three terms of the Fourier series in fast expansion. Temperature fields are presented, and an analysis of the influence of the plate sizes and the heat release magnitude on their formation is given. Recommendations on the plate shape choice are given.

DOI: 10.1134/S0869864316020104

Volumetric properties of near-eutectic liquid LiPb alloys

R.N. Abdullaev1, A.Sh. Agazhanov2, R.A. Khairulin2, and S.V. Stankus2
1Novosibirsk State University, Novosibirsk, Russia
2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: gamma-method, density, lithiumlead alloys, mel
Pages: 247253

Abstract >>
The density and the thermal expansion of liquid lithiumlead alloys with Pb content of 83.0 and 84.3 at. % was measured using gamma-ray attenuation technique over the temperature range from liquidus to 1000 K. The density change during solidliquid phase transition was directly measured for the first time for Li15.7Pb84.3 alloy. A comparison of the obtained results with literature data has been carried out.

DOI: 10.1134/S0869864316010116

Enhancement of figure of merit of thermoelectric materials: a new theoretical approach

A.H. Sofi1, B. Abubakr2, and M.A. Shah1
1National Institute of Technology, Srinagar, Jammu and Kashmir, India
2M.S. Ramaiah Institute of Technology, Bangalore, Karnataka, India
Keywords: thermoelectric efficiency, thermoelectric parameters, extremum, saddle point, nanoforms
Pages: 255260

Abstract >>
Thermoelectric materials have attained importance because of the gargantuan energy crisis the world faces today. A thermoelectric material can be used efficiently and frequently, provided, its figure of merit ZT is increased. Also, easy availability, manufacturing, and low cost are the other factors to be considered for a novel ther-moelectric material. A theoretical model is proposed in this paper for the enhancement of the figure of merit of thermoelectric materials.

DOI: 10.1134/S0869864316020128

Thermophysical processes initiated by inert-matrix-hosted nanoparticles heated by laser pulses of different durations

A.V. Kalenskii1, A.A. Zvekov2, A.P. Nikitin2, and B.P. Aduev2
1Kemerovo State University, Kemerovo, Russia
2Institute of Coal Chemistry and Material Science SB RAS, Kemerovo, Russia
Keywords: melting, laser radiation, nanoparticles, gold, elements with nonlinear optical properties, pentaerythritol tetranitrate, hyperthermia cancer therapy, optical detonator
Pages: 261269

Abstract >>
In the present study, a model for the heating of inert-matrix-hosted metal nano-particles with laser radiation taking into account the melting processes is examined. The calculations were performed using the characteristics of gold and pentaerythritol tetranitrate materials. The kinetic dependences of the temperature and molten-layer thickness on nanoparticle surface were calculated. The main non-dimensional govern-ing parameters of the model were identified. An expression for the maximum thickness of molten layer was obtained. The results can be used in predicting the stability of nonlinear-optics devices with hosted gold nanoparticles, in raising the efficiency of hyperthermia cancer therapy, and in optimizing the optical detonators.

DOI: 10.1134/S086986431602013X

Circular radiation heat shields with temperature dependent emissivities: transient and steady-state analyses

H. Yu, X. Li, S. Hu, Z. Li, and A. Chen
Qingdao University of Technology, Qingdao, China
Keywords: circular radiation heat shield, transient response, steady state shield temperature, Heat transfer rate, temperature-dependent emissivities
Pages: 271280

Abstract >>
Radiation heat loss is an important type of heat loss in thermal systems. In this work, a numerical study of the transient response of two circular radiation heat shields in-serted between two parallel and circular surfaces of emissivities ε1 and ε2 is pre-sented. The same dimensions have been assumed for the two main radiating surfaces and the two radiation shields. The radiation shields are assumed to have different emissivities on their top (ε3 and ε5) and bottom (ε4 and ε6) surfaces, and both are as-sumed to be different but linear functions of temperature. A specific configuration is investigated in detail to highlight the transient temperature and heat transfer characte-ristics of the system. Some new results for the transient temperature and heat transfer characteristics of the system such as the effect of shield location, shield emissivities, the temperature dependence of shield emissivities, system dimensions, temperatures of the hot and cold surfaces and emissivities of the hot and cold surfaces are pre-sented for future references. It has been observed that increasing the temperature of the first radiation shield by changing a parameter such as surface emissivity or dis-tance between the radiation shield or the temperature of the hot surface, will not nec-essarily decrease the temperature of the second radiation shield.

DOI: 10.1134/S0869864316020141

Thermal calculation for a furnace with three-tiered near-wall burners

D.B. Vafin and A.V. Sadykov
Nizhnekamsk Institute of Chemical Technology, Nizhnekamsk, Russia
Keywords: radiation, temperature, heat transfer, combustion, turbulence, radiation chamber, heat flux
Pages: 281288

Abstract >>
The paper considers using a differential method for thermal calculation of a furnace with finding the thermal and aerodynamic parameters within the radiation chamber of a tube furnace. The furnace is equipped with acoustic-type burners allocated in three tiers on the lateral walls. The method implies joint numerical solution of 2D radiation transfer equations using the S2-approximation of the discrete ordinate method, of energy equations, flow equations, k-ε turbulence model, and single-stage modeling of gas fuel combustion. Typical results of simulation are presented.

DOI: 10.1134/S0869864316020153

An effective approach to optimizing the parameters of complex thermal power plants

A.M. Kler, P.V. Zharkov, and N.O. Epishkin
Melentyev Energy Systems Institute SB RAS, Irkutsk, Russia
Keywords: optimization of parameters of thermal power plants, coal power unit, ultra supercritical parameters
Pages: 289296

Abstract >>
A new approach has been developed to solve the optimization problems of conti-nuous parameters of thermal power plants. It is based on such organization of opti-mization, in which the solution of the system of equations describing thermal power plant, is achieved only at the endpoint of the optimization process. By the example of optimizing the parameters of a coal power unit for ultra-supercritical steam parame-ters, the efficiency of the proposed approach is demonstrated and compared with the previously used one, in which the system of equations was solved at each itera-tion of the optimization process.

DOI: 10.1134/S0869864316020165

Characteristics of pulse detonation engine versus ramjet characteristics

A.J. Egoryan1, A.N. Kraiko1, K.S. Pyankov1, and A.P. Tishin2
1Baranov Central Institute of Aviation Motor Development, Moscow, Russia
2TESIS Ltd., Moscow, Russia
Keywords: pulse detonation engine, ramjet engine, thrust, specific impulse
Pages: 297300

Abstract >>
We discuss the method of comparing pulse detonation engines (PDE) and engines with combustion in subsonic flow (ramjet) by means of their specific impulse used by the Center of Pulse-Detonation Combustion (CPDC). We demonstrate that the method used by CPDC to calculate the performance of PDE overstates the value of specific impulse relative to its actual value by a factor of at least two. In contrast, the values of specific impulse for ramjet are understated. As a result, the specific impulse of PDE significantly exceeds that of ramjet or is close to it. We investigate these misleading conclusions, and demonstrate their complete failure.

DOI: 10.1134/S0869864316020177

A swirling jet with vortex breakdown: three-dimensional coherent structures

S.V. Alekseenko1,2,3, V.M. Dulin1,2, M.P. Tokarev1,2, and D.M. Markovich1,2,3
1Novosibirsk State University, Novosibirsk, Russia
2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
3Tomsk Polytechnic University, Tomsk, Russia
Keywords: swirling jet, vortex core breakdown, coherent mode, tomographic PIV, POD
Pages: 301304

Abstract >>
The paper reports on shape of a three-dimensional coherent structure in a velocity field of a high-swirl turbulent jet with the bubble-type vortex breakdown. A set of the 3D instantenous velocity fields was measured by using the tomographic particle image velocimetry (tomographic PIV) technique and processed by the proper orthogonal decomposition (POD) method. The detected intensive coherent velocity component corresponded to a helical vortex core of the swirling jet and two secondary spiral vortices. The entire coherent structure was rotating around the jet axis in compliance with the direction of the flow swirl. From the 3D data it is concluded that the dynamics  of the strsucture can be described by a traveling wave equation: Re[A(y, r)×ei(mθ + ky − ωt)] with the number of the spiral mode m = +1 for positively defined k and ω.

DOI: 10.1134/S0869864316020189

Suppression of vortex core precession in a swirling reacting flow

I.V. Litvinov1,2, A.V. Nazarov1, and S.I. Shtork1,2
1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
Keywords: precessing vortex core, laser Doppler anemometry (LDA), acoustic sensors, vortex burner with tangential feed
Pages: 305308

Abstract >>
The influence of combustion effect on unsteady vortex structure in the form of precessing vortex core was studied using the non-intrusive method of laser Doppler anemometry and special procedure of extracting the non-axisymmetric mode of flow fluctuations. The studies show that combustion has a significant effect on the parameters of such a core, reducing the amplitude (vortex deviation from the burner center) and increasing precession frequency. At the same time, the acoustic sensors detect almost an order reduction in the level of pressure pulsations generated by the precessing vortex core. Moreover, distributions of tangential velocity fluctuations and cross-correlation analysis show that vortex precession is quite pronounced even under the combustion conditions, bringing a significant coherent component to distributions of velocity fluctuations.

DOI: 10.1134/S0869864316020190

80th Anniversary of Ivan I. Gogonin

Editorial Board
Siberian Branch of the RAS, Novosibirsk, Russia
Pages: 309310

Abstract >>
On March 12, 2016 a famous Russian scientist in the field of thermophysics, Doctor of Technical Sciences, Professor Ivan I. Gogonin became 80 years of age.

DOI: 10.1134/S0869864316020207