The paper presents results of experimental study for a flow on the windward side of a swept wing with disturbance generators installed on the surface. These generators are 3D roughness elements with the height comparable to the boundary layer thickness. The method of liquid crystal thermography was used for studying the impact of roughness elements with different heights on the boundary layer. There exists a zone of maximal susceptibility of the flow to the disturbance generated past the roughness element on the wing surface.
A method for treating experimental data obtained on a setup with free oscillations over the pitching angle of the model and for determining the unsteady aerodynamic characteristics of the pitching moment coefficient is described. It is found that the pitching moment coefficient of a re-entry vehicle model at Mach numbers M = 2 and 2.25 and fixed angles of attack a depends non-linearly on the rate of change of the angle a . This circumstance makes the concept of aerodynamic derivatives inappropriate for mathematical description of the pitching moment coefficient.
A method for treating experimental data obtained on a setup with free oscillations over the pitching angle of the model and for determining the unsteady aerodynamic characteristics of the pitching moment coefficient is described. It is found that the pitching moment coefficient of a re-entry vehicle model at Mach numbers M = 2 and 2.25 and fixed angles of attack a depends non-linearly on the rate of change of the angle a . This circumstance makes the concept of aerodynamic derivatives inappropriate for mathematical description of the pitching moment coefficient.
P. Promthaisong1, V. Chuwattanakul2, S. Eiamsaard1
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:150:"1Mahanakorn University of Technology, Bangkok, Thailand 2King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand";}
Keywords: heat transfer, passive heat transfer, swirl, turbulent periodic flow, twisted square duct
Heat transfer, local distributions of Nusselt number, flow structure, and friction characteristics of twisted square ducts are presented. Numerical analysis was carried out to investigate the influence of the twist ratio ( TR = p / D = 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0) on the thermal-hydraulic performance of twisted square ducts under constant wall heat flux condition for Reynolds numbers based on the hydraulic diameter of the twisted square duct ranging from 3000 to 20 000. The straight square duct was also analyzed for comparison. The numerical results showed that the twisted square ducts were more efficient in heat transfer than the straight square ducts because the swirl flow helped to increase fluid mixing and reduce thermal layer boundary thickness. The decrease of the twist ratio led to the increase in the Nusselt number and friction factor due to the higher frequency of swirl flow. As compared to the straight square duct, the twisted square ducts with TR = 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0 improved heat transfer by 52, 49.82, 45.85, 42.22, 39.54, 35.41, and 31.77 %, respectively. Among the studied twisted ducts, the ones with twist ratio TR = 3.5 offered the maximum thermal enhancement factor of 1.42 at Re = 3000. In addition, the results also revealed that the twisted square ducts are thermo-hydraulically superior to the straight square ducts.
The results of computational and experimental studies of the flow around a symmetric airfoil with a relative thickness of 12% in the free stream and in a low-velocity wind tunnel with a closed test section are presented. The experiments are performed for the Reynolds number Rec = 0.7·106-2·107 and angles of attack a = -12°¸ 12°. The problem is numerically solved in a 2D formulation by using the ANSYS Fluent software package. The mathematical model of the flow includes steady Reynolds equations closed by different turbulence models, including the k-w SST model, which is a superposition of the k - e and k-w models. A significant effect of blockage of the wind tunnel test section with limited dimensions by the airfoil on the flow character and aerodynamic characteristics of the airfoil even if the block-age coefficient is only 5.7% is demonstrated.
M. Pirmohammadi1, A. Salehi-Shabestari2 1Islamic Azad University, Pardis, Iran 2Niroo Research Institute, Tehran, Iran
Keywords: magneto-convection flow, inclination angle, Rayleigh number, Hartmann number, Nusselt number
In this study, laminar magneto-convection flow of a viscous fluid in an inclined enclosure is considered. The temperature gradient is applied on two opposing walls while the other two walls are maintained adiabatic. In order to solve the governing non-linear differential equations, an in-house developed code based on the finite volume method is utilized. The fluid of interest is molten sodium whose thermal and electrical properties such as heat capacity, thermal and electrical conductivity are temperature dependent. Representative results illustrating the effects of the enclosure inclination angle on the contour maps of the streamlines and temperature are reported and discussed. In addition, results for the midsection velocity profile and the average Nusselt number at the hot wall of the enclosure are presented and discussed for various inclination angles and Hartmann numbers. It is observed that for Hartmann number of 600, an increase in the inclination angle leads to the growth of the number of vortices in the enclosure.
A model was developed for solids-liquid flow with any solids concentrations. The model includes the two-phase flow equations for the entire flow. It includes also the rheology law and the particle transfer equation with account for interphase slipping. The statistical model of turbulence accounts for the turbulence modulation by particles. The model was tested on a problem about a steady state flow with suspended heavy particles in a horizontal pipe. Comparison with experimental data and other accurate simulations demonstrated that this new model is useful for predicting the features of turbulent suspension flows. The secondary flows in a pipe show three-layered structure of the two-phase flow.
M.A. Pakhomov, V.I. Terekhov
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: film cooling, thermal efficiency, gas-droplet wall jet, injection through the holes, trench, numerical simulation
The flow structure and thermal efficiency of a gas-droplet wall jet, injected through inclined holes into a transverse trench, is analyzed numerically. The predictions are carried out using three-dimensional RANS equations in the following ranges of two-phase flow parameters: initial droplet size d 1 = 0 -20 mm and their mass fraction M L1 = = 0 - 0.05. Gas turbulence is simulated using the model of Reynolds stress transport taking into account the two-phase character of the flow. The obtained simulation results are compared using the Eulerian and Lagrangian descriptions. The applicability of both approaches to describing the dynamics and heat transfer of a two-phase wall jet is shown.
B.F. Boyarshinov, S.Yu. Fedorov
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: cellular flame, non-contact measurements, PIV and CARS methods, momentum transfer
To simulate a cellular flame, rich (equivalent ratio Ф = 1.4) and lean (Ф = 0.9) propane-butane/air mixtures were used in a burner, which forms a stationary flame with a single cell. Experimental data on the temperature fields were obtained using the coherent anti-Stokes Raman scattering (CARS) method; the velocity components were measured using PIV (Particle Image Velocimetry) equipment. The terms of friction stress and static pressure in the momentum transfer equations were calculated using the balance method. It is shown that the equality of dynamic and static pressures associated with the thermal expansion of the combustion products is satisfied on the cellular flame surface. Flameout occurs when the magnitude of the pressure head becomes greater than the magnitude of a static pressure change. The shear stress profiles contain extrema, whose coordinates are associated with streamline curvatures and are close to the position of the heat release region at combustion of lean and rich mixtures.
P.A. Statsenko1,2, M.N. Khomyakov1,2 1Institute of Laser Physics SB RAS, Novosibirsk, Russia, Novosibirsk, Russia 2Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: laser cladding, particle flow, energy attenuation, modeling, diffraction approximation
In laser cladding, the interaction of laser radiation with the powder flow and the substrate plays a key role. Surface heating depends on the distribution of radiation on the surface of the material, which is determined by the interaction of radiation with the flow of the powder microparticles. Usually, in models for calculating laser beam attenuation, the interaction of radiation with microparticles is limited to a simple geometric consideration based on the ratio of the cross-section area of the particles to the total area of the cross section under consideration, without taking into account the influence of diffraction. Radiation propagation is also considered in еру geometric approximation. The presented model allows taking into account the phenomenon of diffraction on powder microparticles. The results obtained using the model with radiation propagation in the geometric approximation are compared with the model with radiation propagation in the diffraction approximation proposed by the authors. It is shown that the numerical model of radiation attenuation and propagation in the diffraction approximation is applicable for complex analysis of the interaction between a laser beam, a particle stream, and a surface. The model allows estimating the beam attenuation due to interaction with the flow of microparticles and obtaining the intensity distribution on the surface of the substrate.
The graph-analytical method (gray model) for estimating the true temperature of an opaque material from both above and below at the unknown character of emissivity dependence on the wavelength is presented. It is shown that if the diagram of spectral distribution of inverse radiance temperatures in the selected spectral range can be approximately represented by a line, convex downwards, then the obtained value of the spectral ratio temperature limits the true temperature from above. If the diagram of indicated dependence in the spectral interval can be represented by a line, convex upwards, then the obtained value of the spectral ratio temperature limits the true temperature from below. The solution to this inverse problem should be combined with the solution to the direct problem. As a result, additional information on the spectral distribution of the material emissivity in the selected spectral range appears. In addition, this is verification of the assumptions made. The paper also provides an example of processing experimental data known from publications.
V.V. Bakovets1, A.V. Sotnikov1, A.Sh. Agazhanov2, S.V. Stankus2 1Nikolayev Institute of Inorganic Chemistry SB RAS, Novosibirsk, Russia 2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: real structure, thermophysical properties, sulfides of rare earth elements, solid solutions
The work is devoted to the study of temperature dependences of thermal conductivity (T = 300-770 K) of polycrystallic samples of solid solutions based on gadolinium and dysprosium sulfides of the compositions: γ-Gd x Dy1- x S1.49 (x = 0.1, 0.2, 0.3, 0.4). It has been found that the morphological features of samples, namely, the specific surface area of crystallites, which causes a change in the number of deformation centers, determines the value of the thermal conductivity of γ-Gd x Dy1- x S1.49 solid solutions. The presence of an abnormal decrease in thermal conductivity for the composition of x = 0.2 has been established. When the temperature increases to 770 K, this anomaly decreases slightly. The minimum value of the thermal conductivity coefficient of 0.68 ± 0.03 W/(m×K) is reached for the com-position under consideration·at 770 K.
A mathematical model of solidification of an iron-based binary alloy (Fe-C) modified with nanosize high-refractory particles is proposed. The processes of alloy heterogeneous nucleation on the surface of nanosize particles and those of alloy crystallization in a cylindrical mold are described. For liquidus temperature, a linear approximation of the concentration of dissolved carbon is adopted; the law of change of this temperature obeys the non-equilibrium lever rule. The volume of the solid phase formed around a nucleus during the crystallization determines the characteristic size of the grain structure in the solidified alloy. Numerical simulation of melt solidification in a cylindrical crucible was carried out, and the kinetics of heterogeneous nucleation and growth of the solid phase was analyzed. It was found that the conditions for nucleation and crystallization differ substantially within the casting. It is shown that, as the melt undergoes cooling, volume-sequential crystallization gets established.
The paper presents the results of experimental study on melting simulator of the fuel coating pin cladding made of alloy Pb (44.5 %)-Bi (55.5 %) and the flow of the melt on the surface of the heated rod. Experiments were conducted for different parameters: heat release, initial temperature, linear size, and the cladding thickness. All experiments provided the video of the process of formation and relocation of the melt, and the cladding temperature and mass loss rate were measured. The paper presents analysis of melt formation and relocation on the fuel rod imitator surface.
Using the laser flash method the thermal conductivity of the Rb-Bi liquid alloy with a bismuth content of 27 at. % was measured in the temperature range from the liquidus point to 1173 K. Approximation equations for thermal conductivity and thermal diffusivity have been obtained, and a table of reference data has been developed. An analysis of the measurement results confirms the existing assumption of the presence of intermetallic complexes with a partially ionic nature of the interatomic interaction in Rb-Bi melts.
On May 30, 2020, the outstanding Russian scientist in the field of thermophysics, energy, and energy saving, Academician of the Russian Academy of Sciences, Scientific Director of the Institute of Thermophysics SB RAS Sergey V. Alekseenko turned 70 years of age.
On April 24, 2020, the famous scientist in the field of fluid mechanics, Doctor of Physical and Mathematical Sciences, Professor Viktor V. Kozlov became 75 years of age.
V.L. Okulov1, E.S. Gesheva2, P.A. Kuibin1, S.I. Shtork1, J. Sorensen1,3, D. Wood1,4, S.V. Alekseenko2 1Novosibirsk State University, Novosibirsk, Russia 2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 3Technical University of Denmark, Lyngby, Denmark 4University of Calgary, Calgary, Canada
Keywords: vortex dynamics, helical vortex
The motion of a helical vortex and the movement of the fluid particles along its axis are analyzed. The same form of the helical axis of the vortex and the trajectory of the particles sometimes leads to a false assumption of equality of these two different motions. The correct identification of both motions, however, is essential when considering the helical vortices in the wakes of rotors, or the displacement of the core of helicoidal tornado, etc. Only the same helical shape is the vortex axis and the streamline of the fluid particles can mistakenly merge these two different motions as the identical travel. We describe an experiment that clearly separates these two motions for the case of a stationary helical vortex, along the axis of which the fluid particles intensively move. The result shows that the absolute velocity of fluid particles does not coincide with the motion of the helical vortex as a whole.
V.L. Okulov1,2,3, Y. Fukumoto4 1Novosibirsk State University, Novosibirsk, Russia 2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 3Technical University of Denmark, Lyngby, Denmark 4Kyushu University, Fukuoka, Japan
Keywords: vortex dynamics, helical vortex, Gaussian vorticity distribution, self-induced rotation
The paper presents an analytical solution for helical vortices with a Gaussian vorticity distribution in the core, which is confirmed by experimental and numerical simulations. This result is obtained by extending the Dyson method to the Biot-Savart law. Previously, analytical solutions were found and studied only for vortices with constant vorticity distribution in the core (a Rankine-type vortex core). One of the important issues raised during the discussion is the difference between self-induced movements of helical structures with both types of vortex core. The proposed solutions are important for the fundamental understanding and description of the behavior of helical eddy flows in various fields of industry and in nature. Examples include tip vortices behind the rotors of wind or hydro turbines, tornadoes, or axial vortices in aerodynamic devices such as vortex apparatuses and generators; cyclone separators, combustion chambers, etc.
A.V. Kashkovsky1, P.V. Vashchenkov1, A.A. Shevyrin1, A.N. Krylov2, A.Yu. Skorovarov2, M.P. Shuvalov2 1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia 2S.P. Korolev Rocket and Space Corporation "Energia", Korolev, Moscow Region, Russia
Keywords: direct simulation Monte Carlo (DSMC) method, aerodynamics, reentry vehicle, chemical models
Numerical studies of the aerodynamic characteristics of the “Federation” reentry vehicle are performed by the direct simulation Monte Carlo method for an altitude of 90 km. Quantitative effects of a number of physical and chemical models of this method on the aerodynamic performance of the vehicle are demonstrated.
I.I. Mazhul
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: supersonic flow, air intake, rectangular duct, longitudinal vortex structures
Results of a numerical study of the flow structure in the rectangular duct of a model air inlet with the interaction of the shock wave generated by the inlet cowl with the turbulent boundary layer on the inner duct surfaces are reported. A configuration involving a convergent entrance section and a constant-cross-section throat was analyzed. The numerical simulation of the three-dimensional flow with free-stream Mach number M = 4 was performed on the basis of the Reynolds-averaged Navier-Stokes equations and the k-w SST model of turbulence. As a result of the calculations, the limit streamlines and the distributions of static pressure on the duct surfaces, as well as the distributions of total pressure and the fields of Mach number in duct cross sections were obtained. The structure of the flow is analyzed and the possibility of occurrence of longitudinal vortex structures in the corner region of the intake-duct throat is shown.
A.A. Khalatov1,2,3, E Shi-Ju2, Dongyun Wang2, T.V. Donyk1,3 1Institute of Engineering Thermophysics NAS of Ukraine, Kiev, Ukraine 2Zhejiang Normal University, Jinhua, China 3National Technical University of Ukraine, Igor Sikorsky Kyiv Polytechnic Institute, Kiev, Ukraine
Keywords: trench, two rows of holes, efficiency of film cooling, computer simulation
The paper presents the results of computer simulation of film cooling behind two rows of trenches on an adiabatic surface with coolant supply through inclined round holes located in the trench. The calculations were carried out in the range of injection parameter from 0.4 to 2.2 using the commercial computer package ANSYS CFX 14 and the SST turbulence model. It was found that for the injection parameter m > 0.6, asymmetry of the film cooling efficiency is observed behind the second trench, which increases with a growth in the injection parameter. This is explained by the unsteady nature of interaction of the cooling jets from the holes of the first and second rows. In the area between the first and second rows of trenches near the end “strips” the film cooling efficiency is 5-10% higher than near the middle ones, however behind the second trench it is 8-20% lower, which is caused by the staggered arrangement of the injection holes. For all injection parameters, the globally-averaged film cooling effectiveness near the end “strips” of the adiabatic surface is lower than that near the middle ones.
Unsteady thermal gravitational-capillary convection in a rectangular cavity with sudden heating of one of the vertical walls by electric current was experimentally investigated. The development in time of the spatial form of ethyl alcohol flows with the Prandtl number Pr = 16 at 20°С was studied. The development of the hydrodynamic boundary layer on the heated wall and the flow along the free surface of a liquid layer was examined. The profiles of the vertical and horizontal velocity components were measured during the development of boundary layers and flow in a volume of liquid. Evolution of temperature fields on the free surface of a liquid layer was studied using a thermal imager.
Yu.M. Kulikov, E.E. Son
Joint Institute for High Temperatures RAS, Moscow, Russia
Keywords: thermoviscous fluid, turbulence, kinetic energy, mixing, Reynolds averaging, stationary turbulence, time scale, turbulent heat flux, inhomogeneous turbulence, filtration, averaging moments, advection, dissipation, diffusion, turbulent transport
Turbulent flow of thermoviscous liquid is studied in a three-dimensional region with periodicity in two directions. Flow characteristics are described in the terms of equation for turbulent kinetic energy: this allows to differentiate contributions from different components related to generation, transport and dissipation of turbulent kinetic energy. Those terms can be calculated from averaging of moments of different order. The previous studies demonstrated that thermoviscous liquid flow occurs through several stages of evolution, including the unsteady turbulence. This allows discussing the problem of mathematical rigorous statement and applicability of different methods for averaging. Existence of spatial periodicity allow using a combined spatial-time averaging for different values on the interval of steady turbulence. Results are presented as a set of Z - t -diagrams. Besides, the paper presents analysis of flow development on the basis of direct visualization of velocity and temperature.
The present study is aimed at the development of a laser Doppler anemometer (LDA) for investigating high-velocity multiphase flows. Based on the analysis of the Doppler anemometry methods, requirements to modern LDAs for solving the above-mentioned problems are formulated, and the ways of their implementation with allowance for the present status of laser engineering and spectroscopy are outlined. A prototype of the anemometer with direct spectral analysis with the most updated elemental base is presented. Its workability is demonstrated by an example of supersonic gas-liquid jets; it is also shown that the anemometer can be also applied to solve other problems.
The results of numerical simulation of the flow structure and heat transfer in a vertical polydispersed bubbly flow are presented. The mathematical model is based on the Euler approach taking into account the effect of bubbles on the mean characteristics and turbulence of the carrier phase. The polydispersed distribution of bubbles size in a two-phase flow is modeled by the method of delta approximation considering the process of bubble break-up and coalescence. Carrier phase (fluid) turbulence is predicted using the Reynolds stress transport model. The simulation results showed good agreement with the experimental data presented in the literature. The measured and predicted thermal-hydraulic parameter distribution indicates that in a turbulent bubbly flow, the wall friction increase is greater than heat transfer enhancement.
M.A. Goldfeld
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: supersonic flow, ignition, combustion, flame stabilization, flow control
The paper presents a study for conditions for hydrogen self-ignition and flame spreading in a supersonic combustion chamber at the Mach number for the inlet flow equal to 4. The experimental model is a rectangular channel with a flame stabilizer performed as a backward-facing step. The fuel was injected before the step at the top and bottom walls through 8 round orifices which were oriented at angles 45° or 90°. Testing was performed for a wide range of flow parameters which were close to the flight conditions. The experiments performed allowed an efficient scheme of fuel injection for the processes of self-ignition and flame stabilization, which permits preventing choking the channel. It was found that the choice of the injection scheme and fuel injection pressure are critical for ignition conditions and allow controlling the combustion process.
Hydrophobic and highly hydrophobic zirconium oxide coatings are obtained by air-plasma spraying of powder and suspension materials. The proposed method and the developed equipment make it possible to obtain nanostructured surfaces with water-repellent properties. The high hydrophobicity of the coating is achieved by creating a hierarchical texture of its surface obtained by the combined method of plasma spraying of powder and liquid-phase materials. The developed surface of the coating based on zirconium oxide ZrO2 obtained by the method of sequential plasma spraying of micropowders (with 20-40 μm microparticle sizes) and liquid materials in the form of suspensions (with 50-100 nm nanoparticle sizes) makes it possible to increase the water-wetting angle up to 145 degrees.
V.A. Arkhipov1, V.D. Goldin1, V.V. Shekhovtsov2, O.G. Volokitin2, A.S. Anshakov3, V.I. Kuzmin4 1Tomsk State University, Tomsk, Russia 2Tomsk State University of Architecture and Construction, Tomsk, Russia 3Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 4Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: low-temperature plasma, silica, precursor porous particles, particle heating and melting, hollow microspheres, Laplace pressure, morphology of microspheres
The paper presents results of numerical simulation for the process of production of hollow microspheres during heating and melting of porous particles of silica (the precursor) by a flow of low-temperature plasma. This model takes into account the partial capturing of gas in the particle and offers the laws of evolution for the hollow microsphere diameter and the wall thickness for different precursors with the size D 0 = (50-150) microns and porosity P p = (0.2-0.6).
A.E. Chesnokov1, A.V. Smirnov1, T.M. Vidyuk1,2 1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia 2Institute of Solid State Chemistry and Mechanochemistry SB RAS, Novosibirsk, Russia
Keywords: mechanical milling, mechanical activation, agglomerated particle, planetary mill, specific surface, plasma torch, spheroidization, dense spherical particle, hollow particle, composite material
In the present paper, results of a study of the impact of high-energy effects on the surface morphology and on the formation of the internal structure in PMS-1 copper particles are reported. It is shown that the mechanical milling of the copper powder in a planetary mill leads to the formation of powder agglomerates with a layered structure consisting of numerous deformed ultrafine particles. It is found that the volume of the agglomerated particles involves defects in the form of microcracks and closed micropores with some content of the initial gas. Subsequent treatment of the powder in an argon-helium plasma jet leads to the formation of dense particles, as well as particles with distributed gas volumes or a single cavity. It was found that, as the molten metal interacted with localized gas volumes during the plasma treatment, local oxidation of the material occurred. A dispersion-strengthened structure with copper oxide compounds of a predominantly round shape, ranging in size from tens of nanometers to 7 μm and uniformly distributed over the particle volume, was formed.
S.D. Sleptsov1, N.A. Savvinova2 1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 2Ammosov North-Eastern Federal University, Yakutsk, Russia
Keywords: ice, one-phase Stefan problem, radiation scattering, temperature field, melting rate
Formation of a temperature field and melting rate of ice vertically located on an opaque substrate and scattering radiation at radiant heating were studied numerically. To solve the part of the problem concerning radiative heat transfer, we used a modified method of mean fluxes, which takes into account volumetric absorption and scattering of radiation in the medium, as well as the selective nature of the radiation source. The influence of spectral volumetric properties of ice on melting and temperature rise of the non-irradiated side is shown. Comparison of calculation results with experimental data shows satisfactory agreement.
Using the laser flash method and the drop method, the thermal conductivity and the enthalpy increment of the eutectic K-Pb alloy (with a Pb content of 90.7 at.%) were measured in the temperature range from the liquidus point up to 1077-1175 K. The specific heat capacity and thermal diffusivity of the alloy were calculated. Approximation equations for the studied properties were obtained, and a table of reference data was developed. It was shown that the thermal conductivity of the liquid eutectic is less than that of pure lead and increases with temperature.
I.S. Anufriev1, E.Yu. Shadrin1, E.P. Kopyev1, O.V. Sharypov1, V.V. Leschevich2 1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 2Luikov Institute of Heat and Mass Transfer NASB, Minsk, Belarus
Keywords: liquid fuel, steam, spraying, shadow photography method, size distribution
The direct shadow photography method was applied for study of size distribution of droplets produced in liquid fuel atomization by a high-speed jet of superheated steam. This approach for fuel spraying allows eliminating the clogging of fuel lines and atomizers used for combustion of substandard liquid hydrocarbons. The setup has a long-focus microscope lens with optical magnification 7:1; this allows measuring the particles with the size starting from 1 µm. Experiments revealed that the prevailing size of droplets in the fuel spray is 1-2 µm.
On June 17, 2020 Robert I. Nigmatulin, the prominent scientist specialized in mechanics and mathematics, academician of the Russian Academy of Science became 80 years of age.
A. V. Volokitina1, A. A. Kalachev2, M. A. Korets1, T. M. Sofronova3
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:471:"1V. N. Sukachev Institute of Forest, Russian Academy of Science, Siberian Branch Federal Research Center Krasnoyarsk Scientific Center, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, Russian Federation 2A. N. Bukeykhan Kazakh Scientific Research Institute of Forestry and Agroforestmelioration, Shchuchinsk, Republic of Kazakhstan 3V. P. Astaf’ev Krasnoyarsk State Pedagogical University, Krasnoyarsk, Russian Federation";}
Keywords: forest fire protection, vegetation fuels, prediction of vegetation fire behavior
Possibility is considered for improvement of fire protection in larch forests of the Kazakhstan Altai. It is proposed to predict the occurrence of fires and their behavior based on vegetation fuel maps using the computer program for predicting vegetation fire behavior, including fire spread rate, development, immediate effects and assessment of manpower and means to suppress the fire. The vegetation fuel maps (VF maps) are based on the pyrological description of forest types and other categories of sites, as well as on the VF classification developed at the V. N. Sukachev Institute of Forest, Russian Academy of Sciences, Siberian Branch. Vegetation of the Kazakhstan Altai has never been described this way before. For the first time, the larch forest types of this region have been analyzed in terms of the types of primary fire carriers (PFC types), thus making it possible to predict flammability of vegetation plots taking into account weather dynamics. The PFC types in the Kazakhstan Altai larch forests have been identified by analyzing regional descriptions of forest types present in the forestry inventory plan. There is a brief description of the computer programs for making VF maps (PGM) and for predicting fire spread rate, intensity, development and effects (PGM2). A performance test is given to both programs on the example of the Markakolsky Forestry District: examples of VF maps for different periods of the fire season are given and behavior of a conditionally specified surface fire is analyzed. The use of these developments in practice will significantly increase the efficiency of firefighting equipment and financial means, as it will contribute to making optimal decisions in cases of several fires being active and insufficient fire suppression means and manpower available. In some cases, behavior prediction of active fires may prove that there is no need to immediately suppress them.
N. E. Korotaeva, M. V. Ivanova, G. G. Suvorova, G. B. Borovskii
Siberian Institute of Plant Physiology and Biochemistry Russian Academy of Sciences, Siberian Branch, Irkutsk, Russian Federation
Keywords: needles, proteins, seasonal adaptation
The role of stress proteins in the formation of plant adaptability to environmental conditions has not yet been fully revealed. To identify the role of dehydrins (DH) in the strategy of biochemical adaptation in species occupying different ecological niches, we compared the amount and seasonal dynamics of DH in coniferous Scots pine Pinus sylvestris L. and the Siberian spruce Picea obovata Ledeb. during the growing season. Weather conditions during the study period were favorable for photosynthetic activity of conifers. Based on the total monthly intensity of CO2 uptake, the physiological activity of both species did not differ from the average values of this indicator for these species. The quantitative ratio of the constitutive DH content of 72 and 55 kD, which varies depending on the season, as well as the accumulation of «unique» DH for each species, which were located in the high- and low-molecular area of pine and in the medium-molecular area of spruce, turned out to be different in pine and spruce conifers. The obtained results suggest that the occurrence of Scots pine in more arid vegetation conditions, and Siberian spruce in wetter but colder conditions may be associated with the accumulation of certain DH. The ability of Scots pine and Siberian spruce to occupy different habitats may be related to the increased accumulation of constitutive proteins DG 72 and 70 (in pine) and 55 kD (in spruce), but not differences in the composition of DH.
I. N. Egorova, M. S. Konovalov, O. V. Shergina, N. V. Dudareva, G. S. Tupikova
Siberian Institute of Plant Physiology and Biochemistry, Russian Academy of Sciences, Siberian Branch, Irkutsk, Russian Federation
Keywords: association of bryophytes and algae, Cyanoprokaryota, epilithes, South of Siberia
For the first time, information is provided about algobryophytic associations common in mountain taiga regions. The environment-forming organisms these associations are representatives of the genus Hedwigia P. Beauv. (Bryophyta). The research was conducted in the Sokhondinskiy state biosphere reserve (Zabaykalskiy Krai, Russia). We selected algobryophyte communities in the mountain taiga, these associations are function on stones in the forest, stony placers, remnant rocks, rock outcrops, and pebbles. Precipitation is the only source of moisture here. It was found that in moss-carpet of the Hedwigia at higher humidity, the average temperature was 0.6 °C lower than at the same time on the exposed surface of the substrate. In the sod of moss formed on rocks under the forest canopy, compared with open spaces of stony placers, it was warmer by 1-4 °C, and the relative humidity is 4-8 % higher. Representatives of Hedwigia growing on acidic mountain breed are characterized by an acidic reaction of the pH. In all investigated samples of bryophytes discovered epiphytic algae. A total of 68 species from the Chlorophyta (40 species), Cyanoprokaryota (13 species), Streptophyta (8 species), Ochrophyta (4 species), Bacillariophyta (3 species) departments have been registered. Most registered of algae species are typical inhabitants of various terrestrial biotopes. A number of algae genera found are known as lichen symbionts. In the associations were dominated by cyanoprokaryotes-diazotrophs from the Nostoc Vauch. ex Bornet et Flahault and Stigonema C. Agardh ex Bornet et Flahault genera. Significant fluctuations in their numbers in time and space were found. Diazotrophs associated with Hedwigia can serve as a source of nitrogen for this moss. It has been shown, that Hedwigia accumulates 0.7-1.5 (2.2) % of mineral nitrogen. The amount of nitrogen comparable to Hedwigia accumulates one of the dominant moss cover in taiga ecosystems of southern Siberia Rhytidium rugosum (Hedw.) Kindb. This species also forms associations with dominance of the Nostoc и Stigonema . The content of mineral nitrogen in the free-living epigenic and epilitic cyanoprokaryotes of the Nostoc and Stigonema genera can be up to 2-3 times higher than that in the studied mosses.
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V. N. Sukachev Institute of Forest, Russian Academy of Science, Siberian Branch Federal Research Center Krasnoyarsk Scientific Center, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, Russian Federation
Keywords: forest ecosystems, technogenic forests and forestry, recreational forests
A brief overview of studies of technogenic impacts on industrial botany and forest ecosystems is given. A list of the leading Russian scientific schools conducting research in technogenic impacts on forest ecosystems in different regions is demonstrated. The main objects of their studies are named. Schematically in the field of technogenic forestry several groups of research objects have been identified: 1. Forests near output sources of techchnogenic pollution. 2. Forests of green areas around large cities and industrial centers. 3. Urban forests and forest parks; 4. Cultivated forest stands in geographically non-forest areas (steppe, forest-tundra and so on). The necessary generalized of the results their studies and separate these into the branch of biology - technogenic forest science is proved. Also discussed is functioning of recreational forests. These forest stands are included in the structures of forests of green zones, suburban and urban forests, forest parks. In these forests it is important to maintain a positive balance between the excessive anthropogenic load of the residents and their full rest. It is noted, that forest stands, firstly urban forests and forest parks are of reference to regional or governmental authorities, which can and does not rely do it. It is confirmed that the most universal and effective direction for the theory and practice of protection of nature and man is general technogenic forest science.
A. L. Fedorkov
Institute of Biology Komi Scientific Centre, Russian Academy of Sciences, Ural Branch, Syktyvkar, Russian Federation
Keywords: genomic prediction, DNA-markers, wood quality traits, growth traits, breeding value
The literature review concerning genomic selection in forest tree breeding is given. Genomic selection is based on relationships between phenotypic traits and genetic markers (single nucleotide polymorphism, SNP). Using genomic selection it is possible to get genomic estimated breeding value of plus tree without long tree progeny testing in field and selection cycle is significantly shortened. Tree breeding programs with genomic selection for Scots pine Pinus sylvestris L., lodgepole pine P. contorta Douglas ex Loudon, maritime pine P. pinaster Aiton, loblolly pine P. taeda L., Norway spruce Picea abies (L.) Karst., white spruce P. glauca (Moench) Voss, black spruce P. mariana (Mill.) Britton, Sterns & Poggenb., hybrid spruce P. glauca (Moench) Voss. × P. engelmannii Parry ex Engelm., Douglas spruce Pseudotsuga menziesii Mirb. (Franco), eucalypt Eucalyptus L’Hеr. and chestnut Castanea Mill. realized in Sweden, Canada, France, United States, Brazil and New Zealand are shortly described. It is shown that genomic selection is applied mainly for growth traits (height and diameter), quality traits of wood (microfibril angle, wood elasticity and density), as well resistance to fungal diseases and insects. The literature data about optimal number of DNA-markers on the accuracy of genomic prediction are presented. In general estimates of genomic prediction for traits studied were high enough. Taken together these estimates and high economic efficiency due to shortening of breeding cycle it is possible to conclude about prospects of genomic selection in forest tree breeding. The lack of progeny field tests established by full-sib families is limiting factor to apply genomic selection in our country, but clonal archives of plus trees can be used.
G. S. Mironov1, I. M. Danilin2 1Reshetnev Siberian State University of Science and Technology, Krasnoyarsk, Russian Federation 2V. N. Sukachev Institute of Forest, Russian Academy of Science, Siberian Branch, Krasnoyarsk, Russian Federation
Keywords: Siberian Forest Institute, Siberian Institute of Forest Engineering, Siberian Institute of Technology, Krasnoyarsk State Academy of Technology, Siberian State University of Technology, Reshetnev Siberian State University of Science and Technology, history of foundation and development, 90 anniversary, Krasnoyarsk
90-year history of the creation and development of the first forestry higher educational institution in Krasnoyarsk Krai - the Siberian Forest Institute / Siberian Institute of Forest Engineering / Siberian Institute of Technology / Krasnoyarsk State Academy of Technology / Siberian State University of Technology, currently - Reshetnev Siberian State University of Science and Technology. Information is presented on the main stages of the formation of the university, the directions of training forest specialists, and conducting scientific research.
