A.V. Voevodin, A.A. Efremov, V.G. Sudakov
Zhukovskii Central Aerohydrodynamic Institute, Zhukovskii, Russia
Keywords: aerodynamics, civil aircraft, large angles of attack, rotation
A numerical and experimental study of the flow near a standard civil-aircraft model at large angles of attack in the range from 0 to 90° and at subsonic velocities of the oncoming flow has been carried out. The experiments were performed in the T-105 wind tunnel of TsAGI. The calculations were carried out within the framework of solving the Reynolds equations. A comparison of the calculated and experimental integral characteristics showed a good agreement with an accuracy sufficient for practice. Physical features of the flow and their influence on the aerodynamic characteristics of a stationary model at large angles of attack, as well as in the mode of rotation of the model with a constant angular velocity, are revealed.
T.A. Gimon, V.A. Kislovskii, S.V. Lukashevich, S.O. Morozov, M.S. Nikolaev, A.N. Shiplyuk
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: compressible boundary layer, laminar-turbulent transition, linear theory of stability, Gortler vortices, direct numerical simulation
The generation and development of Görtler vortices in a compressible boundary layer on a concave surface has been numerically modeled. The calculation was carried out using the Fluent software of the Ansys program package. Stationary and non-stationary perturbations are analyzed at oncoming-flow Mach number M ≈ 4. It is shown that when a periodic disturbance in the direction transversal to the flow is introduced, it decays on the straight section of the surface, and grows on the concave surface. Comparison of the results of the calculations made with the calculations performed within the framework of the linear theory of stability showed that the range of susceptibility of the boundary layer to disturbances on the concave surface amounts approximately to 17 boundary-layer thicknesses. After the susceptibility zone, disturbances grow exponentially with small deviations. The flow fluctuation profiles are in good agreement with the data obtained from the linear theory of stability. It is shown that the development of a non-stationary perturbation along the surface of the model for the parameters considered in the present study differs little from that of a stationary perturbation.
Data of experimental studies on hydrodynamics of countercurrent flows of liquid and vapor in distillation columns with structured packings are necessary for verification of computational models that describe hydrodynamics and processes of heat and mass transfer in industrial distillation columns. The paper presents a description of the design of a multipoint hot-wire anemometer with a coordinate device, developed to measure the steam flow rate under conditions of jet irrigation of the packing with a countercurrent flow of freon mixture phases. The measurement system was tested with air flowing through a 210-mm layer of Sulzer 500X structured packing. The measurements were carried out using a large-scale research model of a distillation column with a diameter of 900 mm. Experimental data were obtained on the distribution of the local air flow velocity at the outlet of a single-layer Sulzer 500X packing. Scanning the packing plug with a step of 1 and 5 mm showed the presence of a periodic cellular pattern of the gas flow velocity distribution, which correlates with the structure of the studied packing.
A.V. Kashkovsky, A.N. Kudryavtsev, A.A. Shershnev
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: supersonic non-isobaric jets, shock-wave structure, axisymmetric flow, rarefied gas, Direct Simulation Monte Carlo method
The Direct Simulation Monte Carlo (DSMC) method is used to study rarefaction effects on the structure of an axisymmetric underexpanded jet. A comparison with the data of other researchers shows that DSMC simulations accurately reproduce the features of the steady shock-wave structure of the jet. Rarefaction produces a noticeable effect on the jet flow. In particular, it makes the barrel shock in the first shock cell change the type of its reflection from the axis, which leads to vanishing of the developed Mach disk and to changes in the structure of other shock cells. For the first time, the formation of a closed reverse flow region behind the Mach disk is observed in a molecular-kinetic simulation. This phenomenon has been earlier observed only in continuum simulations.
A.V. Minakov1,2, D.V. Platonov1,2, A.V. Sentyabov1,2 1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 2Siberian Federal University, Krasnoyarsk, Russia
Keywords: pressure pulsations, Francis turbine, re-connection, modeling, hydroelectric power station
The influence of asymmetric boundary conditions on flow regimes in a model hydraulic turbine has been investigated. The curved draft tube is shown to have almost no effect on the vortex structure, preserving such a phenomenon as the re-connection of the vortex core. The axial and tangential velocity profiles also remain unchanged. There is a change in pressure pulsations, despite the similarity of the average values and the unsteady vortex flow pattern. In the case of an asymmetric model, the pressure pulsation is higher than for a symmetric model. This may indicate a superposition of pulsations, caused by the rotation of a precessing vortex core, with generated longitudinal (synchronous) pressure fluctuations.
V.V. Markin, P.A. Polivanov, G.A. Berkon
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Keywords: propeller, multirotor aircraft, small Reynolds numbers, thermal anemometry
The paper presents the research into small multirotor vehicles that fly in the surface layer of the atmosphere, where the level of flow disturbances impinging on the blade can change significantly, altering the characteristics of the propeller. Axial streamlining of a constant-pitch two-blade rotor with a diameter of 380 mm was experimentally studied in a low-noise wind tunnel T-324 of ITAM SB RAS. The experiment was carried out in the range of Reynolds numbers up to 1.5∙105, calculated from the flow parameters in the cross section of 75% of the rotor radius. The thermoanemometric method was used as the main measurement method. The influence of pulsations of the incoming flow on the flow characteristics in the propeller wake was established.
In this paper, the characteristics of the electric field, flow field and temperature field of ionic wind heat sink are studied, respectively. The results show that the heat sink achieves the best performance when the ratio of fin spacing to thickness is 5, the electrode spacing is 5mm, the needle position is 0. Furthermore, a two-stage structure ionic wind heat sink is proposed and optimized. The optimized average wind velocity increased by 30.8% to 3.57m/s compared to the single-stage structure. This work enriches the knowledge of electrode configuration and promote the application of ionic wind heat sinks.
The operation of the centrifugal disk pump is experimentally studied. To summarize experimental data, dimensionless parameters are introduced. A method for calculating the flow rate, pressure, and throttle characteristics is proposed. The method ensures accuracy sufficient fort engineering calculations.
S.A. Isaev1,2 1State Marine Technical University of St.Petersburg, St-Petersburg, Russia 2Saint Petersburg State University of Civil Aviation, St-Petersburg, Russia
Keywords: heat transfer enhancement, vortex, inclined groove, plate, narrow channel, numerical simulation, experiment
The RANS approach was used for revealing the phenomenon of interference of a jet flow while deceleration due to interaction with the windward edge of the inclined groove on a streamlined plate and the narrow trench wall; the interaction generates a tornado-like vortex at the groove inlet. Experiments confirmed emerging of extra-ordinary drops in static pressure between the stagnation and rarefaction zones. The return flow velocity increases twice and this velocity magnitude exceeds the superficial velocity. The study justified the separation flow increase and heat transfer enhancement for the cases of inclined grooves on a structured surface. This effect is related with a multiple (up to 6-9 times) growth of relative friction and heat fluxes inside the grooves (compared to the case of a flat wall). We observe also acceleration in the near-wall stream caused by a set of single-row inclined groves in a narrow channel. Here the maximum velocity in the stream core in a structured channel increases by more than 1.5 times as compared the maximal velocity for a flow in a planar-parallel channel. The study performs aerodynamic disigning of new energy-efficient grooves-structures surfaces.
S.V. Alekseenko1, P.A. Shchinnikov2, I.S. Sadkin1,2 1Kutateladze Institute of Thermophysics SB RA, Novosibirsk, Russia 2Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: carbon dioxide power cycles, CO cycle, supercritical carbon dioxide, decarbonization, zero emissions
Four options for the power cycle using carbon dioxide as a working fluid during oxygen combustion of gaseous fuel are considered. In all the cases, heat is supplied in the zone of supercritical parameters of CO2. The fundamental difference in options lies in the method of increasing the working fluid pressure. The heat is supplied to the cycle in the combustion chamber, and the cycle operation is accompanied by continuous updating of the working fluid, since part of CO2 and all steam obtained during fuel combustion are removed from the cycle. It is shown that cycles with a single-stage pump pressure increase have the highest thermal efficiency, reaching 64.5%. The effect of thermodynamic parameters on the energy characteristics of cycles has been estimated quantitatively.
Results of numerical simulation of the combustion of a gas-droplet fuel mixture in an oxidizer flow under conditions typical of hybrid rocket engines are reported. The effect of the size and rate of supply of fuel droplets on the combustion completeness, temperature and position of the diffusion flame in the boundary layer of the oxidizer flow has been studied. It is shown that the influence due to the liquid fuel droplets manifests itself as a local decrease of gas temperature and an increase of the concentration of the gaseous fuel in the immediate vicinity of droplets. The addition of droplets to the gaseous fuel flow results in a slight decrease of the flame thickness and flame temperature, which, however, experience no large-scale perturbations as a result of droplet movement and remain almost stationary.
Combustion of liquid hydrocarbons by spraying them with a jet of superheated steam, carbon dioxide and air has been experimentally studied. Results aimed at identifying the advantages of using superheated steam as a diluent sprayer over other diluent gases were obtained at the example of diesel fuel. For this, thermocouple measurement data were studied and compared, gas analysis of intermediate flame components was performed when fuel was sprayed with various diluent atomizers, and both combustion efficiency and harmful emissions in the final combustion products were compared. It was found that the air spray regime has a higher flame temperature (~ 150°С) in the entire measured range as compared to steam and carbon dioxide spray. At the same time, the regimes with steam and carbon dioxide have similar temperature profiles. Exhaust gas analysis showed that when sprayed with steam, the reduction in NOx reaches 25 and 70% relative to carbon dioxide and air, respectively, which makes its use as a diluent atomizer more preferable when burning liquid fuels as compared to other studied gases.
The research was devoted to the problem of measuring geometric parameters of ice by the method of phase triangulation in a limited volume with refraction of optical signals. This method served to develop an algorithm of measurement and calibration. It was also expedient to take into account the reflective properties of ice and the conditions of external lighting, as well as to ensure a minimum error in measuring the geometric parameters of ice. For this purpose, software complexes to control the quality of the measuring system with current parameters and to calculate the geometric parameters of ice, as well as a software and hardware complex for measuring the geometric parameters of ice by the phase triangulation method in a limited volume with refraction of optical signals have been developed. The measuring system was configured for a measuring volume with characteristic dimensions (100×100×60) mm. A measurement error of 12 microns has been achieved. Experiments were carried out to measure the geometric parameters of ice formed on a cylindrical surface. The values of the local thickness of the ice and the statistical value of the thickness of 1.6 mm have been restored. The developed technologies may be used in experiments on an aerodynamic stand for the study of icing processes aimed at creating anti-icing methods in various fields of industry.
A.B. Kruglov, I.I. Konovalov, B.A. Tarasov, V.S. Kharitonov, L.P. Paredes
National Research Nuclear University (MEPhI), Moscow, Russia
Keywords: heat-conducting liquid metal sublayer, pulse heating method, thermal conductivity of lead-sodium and bismuth alloys
The article presents the results of measurements of thermal conductivity coefficients of Pb-Na with the content of the latter of 20 at. % and eutectic (Pb-Bi)-Na 20 at % alloys at temperatures of 350 - 800 °С. The experimental methodology is described and the temperature differences in the heat-conducting sublayer of fuel cells of the studied alloys are estimated.
The density of liquid lithium fluoride and an eutectic mixture of lithium fluoride and sodium fluoride (with a content of 39 mol. % NaF) was measured by the gamma ray method in the temperature range from liquidus to ~1280 K. The obtained results were compared with the available literature data. The study of liquid eutectic LiF - NaF was carried out in a significantly wider temperature range compared to other authors, and the obtained values of the volumetric coefficient of thermal expansion turned out to be the most reliable.
P.P. Bezverkhii1, O.S. Dutova2 1Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, Russia 2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: methane, combined equation of state, critical point, heat capacities, speed of sound
A new thermal equation of state for methane is proposed in explicit form, including a crossover function. This function comprises new regular and scaling parts with 22 adjustable coefficients written in real temperature-density variables. The coefficients are determined from the ρ, ρ, T-data for CH4. Data on the heat capacities Cv, Cp and the speed of sound W were not involved in calculations, except for the data on the isochoric heat capacity Cv in the ideal gas state and the Cv value at 100 K on the liquid branch of the liquid-gas equilibrium curve. In the regular region, the calculated values of Cv, Cp, and W are close to the experimental and tabulated values. In the critical region, the discrepancies with the tabulated values are no more than 5%, which is associated with the use of the scaling equation of state. The average absolute deviation is 0.3% in the pressure description, the r.m.s. error σp = 0,5 %, and the error in Cv is less than 5%. The calculation results are compared with the known crossover equations of state for CH4. It is concluded that the proposed model of the equation of state is preferable for calculating the thermophysical properties of methane.
a:2:{s:4:"TEXT";s:82:"A.A. Chernov1,2, M.N. Davydov1,3, A.A. Pil’nik1,2";s:4:"TYPE";s:4:"html";} 1Novosibirsk State University, Novosibirsk, Russia 2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 3Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk, Russia
Keywords: gas-saturated liquid, gas bubble, decompression, degassing, boundary value problem with a moving boundary, numerical simulation, magmatic melt
Dynamics of gas bubble growth in a highly viscous gas-saturated liquid (magmatic melt) subjected to decompression is investigated. A mathematical model of the process, which is a joint dynamic and diffusion problem, is proposed. An approximate semi-analytical solution is found based on the existence of a quasi-stationary state for the bubble growth process. The influence of certain factors on the process under consideration at all its stages is shown. In particular, a significant dependence of the bubble growth rate on the decompression rate is illustrated. It is shown that, at long times, bubble growth has a self-similar character and occurs only as a result of gas desorption from the surrounding liquid.
The paper considers a model of nucleation of crystal phase during cooling of a modified melt below the liquidus point. We demonstrated a connection between the overcooling factor, nucleus size forming at the particle surface, and the amount of consumed energy. Numerical simulation was performed for solidification of a modified bicomponent aluminum melt in a cylindrical crucible with account for thermodynamics, heterogeneous nucleation and crystallization. We found the conditions of crystal nuclei formations: both for the cases with the size higher or smaller that the size of seeds. It was shown that efficient modification of the metal needs the use of powders with maximally homogeneous size. The reliability of this model is confirmed by reasonable compliance between the simulation and physical experimental data.
The paper presents the results of the main physical processes that ensure the operation of hollow cathodes of vacuum plasma torches with the formation of high-enthalpy plasma inside the cavity. The interaction of the plasma with the inner surface of the cathode determines the temperature field of the hollow cathode and the distribution of heat fluxes in the vacuum discharge. The formation of the temperature field in the cathode body, in addition to temperature processes, is significantly influenced by the conditions of heat exchange between the cathode and the environment, the characteristics of the cathode material and its geometric dimensions. Studies of plasma emission spectra in the cathode cavity have shown that the appearance of spectrum lines depends on the excitation conditions and determines the energy limits of electrons accelerated in the cathode layer.
The paper presents the results of thermodynamic calculations and experimental studies of plasma processing of biomedical waste and fuel biomass, including waste from the woodworking industry and agriculture, which have shown the promise of using plasma-chemical technology for processing various wastes with production of combustible gas and inert mineral material. Comparison of the experimental results and calculations showed their satisfactory agreement. Both in calculations and in experiments, no harmful impurities were found in the products of plasma processing of the investigated wastes.
On November 30, 2022, an outstanding scientist in the field of thermal physics and thermal power engineering, Doctor of Technical Sciences, Professor, Academician of the Russian Academy of Sciences Alexander I. Leontiev passed away.
A. S. Savchenkova1, A. S. Semenikhin1, I. V. Chechet1, S. G. Matveev1, A. A. Konnov2, A. M. Mebel1,3 1Samara National Research University, Samara, 443086 Russia 2Lund University, S-221 00 Lund, Sweden 3Florida International University, Miami, Florida 33199, USA
Keywords: ortho-pyridyl, meta-pyridyl, para-pyridyl, quantum-chemical simulation
Specific features of the pyridine structure make it a convenient model system to describe coal combustion; however, the main attention of researchers has been paid to the formation of the ortho-pyridyl, whereas the formation of meta- and para-pyridyls has been yet poorly studied. The rate constants of the formation of three pyridine radicals by hydrogen atom abstraction by another hydrogen atom are compared. The geometry of the reactants is optimized within the framework of the density functional theory with subsequent refinement of single-point energies by the ab initio G3(MP2,CC) hybrid method. The calculations show that the formation of ortho-pyridyl is preferable, though the formation and further transformations of all three radicals should be taken into account for a detailed description of the coal combustion process.
A. A. Ponomarev1,2, D. K. Sharaborin1, M. Yu. Khrebtov1, R. I. Mullyadzhanov1,2, V. M. Dulin1,2 1Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia 2Novosibirsk State University, Novosibirsk, 630090 Russia
Keywords: laminar cone flame, gas-droplet combustion, ethanol, finite volume method, OpenFOAM
This paper describes a numerical simulation of a laminar flame of a premixed mixture of ethanol and air at atmospheric pressure with the addition of a suspension of ethanol droplets. The initial fuel-oxidizer ratio in the gas phase is ϕgas = 0.844 and 1.125. With account for the fuel in the liquid phase, the total equivalence ratio is ϕtot = 1.195 and 1.476, respectively. The calculation is performed using the method of direct numerical simulation with a reduced chemical mechanism. Motion, heating, and evaporation of droplets are determined using the Lagrange approximation. The numerical simulation results are verified using experimental data (flame cone photographs and laser-induced fluorescence data). It is revealed that all the droplets evaporate in the flame front heating region and the presence of fuel in the liquid phase significant increases the CO concentration both in the calculation and in the experiment.
S.V. OSIPOV
Pacific Geographical Institute, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
Keywords: landscape, geosystem, geocomplex, soil and vegetation cover, continuous, discrete, pattern
The four most common types of spatial structure (pattern) of landscape cover are identified. The regular nuclear pattern consists of repeating elements and there is a morphologically pronounced dominant, i. e. a nucleus (one or more). The regular denuclear pattern consists of repeating elements, and the nucleus is not pronounced. The irregular nuclear pattern consists of non-repeating elements and there is a morphologically noticeable dominant, i. e. a nucleus (one or more). The irregular denuclear pattern consists of non-repeating elements, and the nucleus is not pronounced. Based on spatial features, the most common types of integration and differentiation of landscape cover are identified. The background integration is caused by a single process (a set of processes) that organizes the entire space under consideration and often predetermines the uniformity of the territory. The central integration is caused by the impact of the center on the surroundings and the surroundings on the center. The catenary integration is caused by the middle and far lateral flows of any nature and by the impact on them. The border integration is caused by the connections and interactions of neighbouring areas at a common border. The background differentiation is caused by a unified process (a set of processes) which forms heterogeneity due to a different intensity. The central differentiation implies the formation of the center which plays the role of the leading or dominant element in the functioning and development of the geocomplex/geosystem, and is determined by a different nature and a different intensity of its interaction with other elements. The catenary differentiation manifests itself in a directional change of the properties of landscape cover along gradients and is caused by a change in lateral flows. The boundary differentiation is related to the fact that the boundaries are often a result of a barrier effect of some processes and the reason for the formation of a barrier effect for other processes (synecological, geochemical, geophysical, and geological). The locus differentiation consists in the formation of a separate patch in geocomponents and geocomplex, in the isolation of some part or in the division of the geocomplex into parts. It is emphasized that the selected types of spatial structure, integration and differentiation are applicable to geocomplexes/geosystems of all levels and to all geocomponents.
V.S. SAVENKO
M.V. Lomonosov Moscow State University, Moscow, Russia
Keywords: global ecosystems, great geological cycle, system-forming process, redox nonequilibrium, mechanism of ecosphere organization
The necessity of identifying a larger (than the biosphere) global ecosystem of geospheric rank, the ecosphere, was substantiated. The boundaries of the ecosphere were determined, which includes all living matter of the planet, the atmosphere up to the thermosphere, the entire hydrosphere and the upper part of the lithosphere with the metamorphic layer. Within this space, a great geological cycle is realized, linking the biosphere and its abiotic environment into a single whole and creating a specific form of its structural and functional organization. The great geological cycle of matter performs the function of a system-forming cyclic process in the ecosphere, which does not have complete closedness. The main factor controlling the degree of closedness of the geological cycle is the exchange of matter at the boundary between the lithosphere and the mantle. The processes of metamorphism occurring outside the biosphere constitute the mechanism of ecosphere organization, which has long supported the existence of life on Earth: they regenerate the products of biospheric metabolism and ensure their return to the biosphere in forms available for re-consumption by living organisms. A characteristic feature of the ecosphere space is the redox nonequilibrium caused by the activity of living organisms. In the ecosphere, a complete life cycle takes place from the formation of living organisms from mineral components to complete transformation into the initial mineral components of living matter and all products of biospheric metabolism. Outside the ecosphere there are neither living organisms nor products of their vital activity that have retained the thermodynamic nonequilibrium acquired in the biosphere.
I.V. BYCHKOV1, I.N. VLADIMIROV2, G.M. RUZHNIKOV1, A.P. SOFRONOV2, R.K. FEDOROV1, A.K. POPOVA1, Yu.V. AVRAMENKO1, S.L. KRAVTSOV3, E.V. CHURILO4 1V.M. Matrosov Institute for System Dynamics and Control Theory, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia 2V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia 3United Institute of Informatics Problems, National Academy of Sciences of Belarus, Minsk, Republic of Belarus 4Forest Institute, National Academy of Sciences of Belarus, Gomel, Republic of Belarus
Keywords: forest, forest resource monitoring, Earth remote sensing, Sentinel-2, satellite images, machine learning
The characteristic features are analyzed and the problems of the forest monitoring of the Baikal natural territory (BNT) are highlighted. An approach is proposed for digital transformation of forest resource monitoring using a service-oriented paradigm, an infrastructure approach, declarative specifications as well as end-to-end and Web technologies for collecting and processing large amounts of spatio-temporal data. A scheme of a digital forest monitoring platform based on an information-analytical geoportal environment is described, including a system for processing and storing spatio-temporal data, a catalog of basic and thematic services for assessing the consequences of natural and anthropogenic impacts on forests of the BNT. The experience of using deep learning methods based on neural networks to monitor changes in the state of forests is presented. Automated determination of the land cover types is carried out on the basis of Sentinel-2 images. The composition of classes of the training data set created for the BNT is described. The result of the satellite image classification with identified land cover classes is given. The digital platform thus created can be used to assess and predict the state of forest resources of the BNT, and to make managerial decisions on effective forest management.
Presented are the results from surveying the swamps in the Altai Republic at permanent stations from 2010 to 2014. At the observation stations located on the Turochak, Kutyushskoe and Balanak swamps, the hydrothermal and gas regimes, and also carbon dioxide and methane emissions were investigated. It is pointed out that during all years of investigation the levels of swamp water remained close to the surface, and the humidity did not fall beyond the limit 0.8 of total moisture capacity. It was found that the extreme values of CO2 and CH4 concentrations in the mesotrophic peat deposit varied from 0.05-1.10 mmol/dm3 to 0-0.62 mmol/dm3, respectively. In the eutrophic deposit, these values were higher: 0.07-1.40 for CO2 and 0-0.65 mmol/dm3 for CH4. It is established that different weather conditions are not the determining factor for the dynamics of gas regime in the peat deposit of eutrophic and mesotrophic genesis. A significant role is played by other, neglected factors. It was found that the concentration of greenhouse gases in peat deposits of a different genesis varied within small limits, and their dynamics under different weather conditions had an unstable regime, but with a general increasing trend toward the underlying rock. It was confirmed that mountain swamps are not a significant source of greenhouse gas emissions. Extreme losses of CO2 and CH4 in total for the summer period were 29.7 to 76.6 g/(m2 summer period) on the Turochak swamp, and 42.1 to 80.9 g/(m2 summer period) on the Kutyushskoe swamp, which is by a factor of 15-43 smaller than the net primary production.
M.A. MARTYNOVA
Research Institute of Agricultural Problems of Khakassia, vil. Zelenoe, Russia
Keywords: invader, deposit, life condition, succession, natural renewal, field-protective forest belts
Presented are the results from studying the invasion of squat elm (Ulmus pumila L.) into vegetation cover of fallow lands provided with elm shelterbelts. It was found that because of abundant fruiting at a young age and in the presence of a healthy state of individuals, Ulmus pumila L. could become a transformer. But this does not happen because a number of biotic and abiotic factors negatively affect the vital state of woody plants and their ability to bear fruit: the existence of animal grazing, a strong degree of soil degradation, climatic conditions (insufficient moisture, frost weathering and drying of the soil), and strong grass cover. As part of the research it was established that on moderately degraded soils, the Ulmus pumila L. spread to all interstrip fields of the system of shelterbelts; in the first layer of phytocenoses, woody plants withstood the winter period quite well. Within seven years, a tendency for a decrease of the number of undergrowth by a factor of 19.9 was observed. The crown density of the tree and shrub canopy was 0.1-0.7. On slightly degraded soils in the presence of grazing, Ulmus pumila L. occupied 33 % of the study area, and 73 % within eight years. Plants of the first layer were few and weakened. The maximum crown density of 0.5-1.0 was observed near field-protective forest belts. The intensive distribution of Ulmus pumila L. was restrained by grazing and a thick layer of dead litter, reaching 4.2-7.5 q/ha of air-dry matter. It was established that on heavily degraded soils, the density of individuals influenced the vital state of undergrowth. In phytocenoses with a sparse undergrowth, the state of life was assessed as “healthy”, “weakened” or “drying out”, and where the undergrowth was thick, as “drying out”. Identification of patterns of formation and development of facies with the participation of Ulmus pumila L. will help to predict a further course of development of successional processes and landscape dynamics in the south of Middle Siberia.
E.E. KONONOV
V.B. Sochava Insitute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: Baikal, terrace complex, genesis, climate, hypsometry, discussion
A critical analysis is made of the available published ideas concerning the role of the leading factors in the formation of Baikal terraces: tectonics, climatic fluctuations of the lake level, and a periodic change of the location of the drain slot. The inconsistency of the assumptions about the dominant role in the creation of lake terraces of different levels (including underwater terraces) of the change of location in the Late Pleistocene of the Irkut direction of the Baikal water discharge to the Angarа direction is shown. These data show that during periods of cooling of the Late Pleistocene, the lake level could presumably decrease by no more than 40-45 m, and its rise during periods of warming could not be higher than the runoff thresholds of the Baikal waters of that time, which rules out the possibility for the formation of a complex of high terraces. The denial of the role of tectonic movements in the formation of lake terraces is in complete contradiction with the actual tectonic activity of the Baikal Depression proven in numerous scientific papers. It is established that tectonic movements play a major role in modeling the relief of the lake basin and determine the hypsometric position of terraced surfaces and their deformation. The available, very few, definitions of the age of terraces do not allow for their correlation. The chief reason for the disagreement on the Baikal terraces is the lack of systematic specialized research on this problem.
V.I. VORONIN, A.P. SIZYKH, V.A. OSKOLKOV
Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: polydominant forests, river basins, hydroregimes, period of flooding, Western Cisbaikalia, Eastern Cisbaikalia
Presented are the results from studying the structural-dynamic organization of the forests in basins of large rivers flowing into Lake Baikal and having a considerable influence on changes in its hydrologic regimes. It is known that annual discharge of rivers essentially depends on the state of the forests growing in their basins. The stability of the hydrologic regime of the rivers accounting for the main volume of water transported into the lake is directly dependent on the functional properties of forests. The preservation of the environment-protective and water-regulatory functions of the forests contributes to a stable functioning of catchment basins of the rivers ensuring lake sustainability in general as an integrated ecosystem within the Lake Baikal drainage basin. It is pointed out that the secular dynamics of forests associated with the succession of forest-forming species (which is typical for the zonal types of vegetation) under climate change promotes the formation of polydominant dark-light-coniferous and light-coniferous forests, also influences the hydrologic regimes of rivers in the study areas. We identified the structural-dynamic organization of forest communities under different physical-geographical conditions and the characteristics of their formation, which made it possible to forecast the vector of possible development of forests within the Lake Baikal drainage basin. It is shown that changes in the structure and dynamics as well as in the spatial organization of forests within the lake’s drainage basin as a consequence of an intensification of fires over the last several decades and recent industrial harvesting affect the river discharge and, as a result, the relatively abrupt water level fluctuations in the lake from year to year. It is established that the trends in forest formation within the basins of the rivers flowing into Baikal are responsible for the relationships in the “forest structure-period of flooding of rivers”, which will influence optimization of forest use within the Lake Baikal drainage basin as a whole.
a:2:{s:4:"TEXT";s:26:"E.S. VOLKOVA, M.A. MEL’NIK";s:4:"TYPE";s:4:"text";}
Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia
Keywords: agroclimatic hazards, probability of frost distribution, period without frosts, growing season, spatio-temporal analysis
Based on a statistical analysis of long-term observations, an assessment is made of the spatio-temporal distribution of frosts in the southern taiga of Western Siberia. In spite of the fact that a steady crossing of the average daily temperature of 5 °C during the last 15 years occurred 5-7 days earlier, on average, there still remains a high likelihood for the onset of frosts every year throughout the study territory. A spatial differentiation of the duration and intensity of frosts is observed; the average annual number of days with frosts from May to September changes from 7.5 in the south-west to 12 in the north-east and significantly varies from year to year. Over the last 35-year period the largest number of days with frosts was recorded in 1986, 1988, 1989, 1991, 1998, 2006 and 2010. The range of variability in the average long-term period without frosts is about 40 days. Frosts are a significant risk-forming factor for agriculture in the study area. To reduce risks in plant production, the probability that frosts occur in spring, summer and autumn is calculated for 10-day periods. It is noted that the greatest risks to the local system of plant production depend on late spring frosts. The probability of frosts in the third 10-day period of May is from 18 to 32 %, and the probability of frosts in the first 10-day period of June for the northwestern part exceeds 10 %. In recent decades, however, the number of events with the most dangerous late spring frosts with the temperature drops to -3 °C and below for most weather stations in the study area has been decreasing. In the region as a whole, a high probability of frosts in the following years cannot be excluded, especially for the spring-summer period.
V.M. NIKITIN, N.V. ABASOV, E.N. OSIPCHUK
L.A. Melentiev Energy Systems Institute, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: reservoir, modeling, transboundary basin, flow change, long-term flow regulation, water balance
This paper addresses the possible consequences of the construction of the Uldza river reservoir in Mongolia which are associated with a change in the hydrological regime of the Torey Lakes and the transboundary basin. Based on data of hydrological observations from 1965-2020, the features of the climatic and hydrological characteristics of the Uldza river and the Torey Lakes are analyzed. It is noted that that the main factor for variability in their hydrological regimes is the cyclic behavior of climate change accompanied by a large amplitude of temperature fluctuations, an extremely uneven distribution of precipitation over seasons and individual years, high water filtration and evaporation losses (often exceeding the local runoff), and periodic drying up of rivers and lakes. Available material of the tender documentation for the Mongolian Onon-Ulz project, open raster data of satellite sounding of the Earth and various GIS sources, and other global data were used to simulate the configuration of the projected reservoir, and its filling and drawdown modes under different water conditions. Based on the simulation results, the quantitative estimates of the possible average monthly deviations of the regulated runoff, levels and area of the water surface of Lake Barun-Torey from the natural conditions were obtained. Calculations of the operating conditions of the designed reservoir show that it can only be filled when the flow rate is 50 % or lower. Thus it will remain unfilled for a long time, which casts some doubt upon the economic expediency of its creation. Despite the low absolute values of the runoff, its relative deviations from the natural conditions vary widely (from 3 to 192 %). The most substantial influence of the reservoir on the deviation of runoff indices, levels, and area of the lakes compared to natural conditions occurs in dry periods. Thus the reservoir creation can lead to a significant change in the natural hydrological conditions of the Uldza river and Torey Lakes and negative consequences for the ecosystem.
V.E. GLOTOV1, V.V. KULAKOV2 1N.A. Shilo North-East Interdisciplinary Scientific Research Institute, Far Eastern Branch, Russian Academy of Sciences, Magadan, Russia 2Institute of Water and Ecological Problems, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk, Russia
Keywords: the Russian Far East, sea shores, therapeutic mud, methane flows, groundwater, sulfate reduction, sedimentary basins
We examine the patterns of formation and distribution of therapeutic marine sulphide-silt muds and the prospects for increasing their resources on the sea coast of the Far East of the Russian Federation. Accumulations of this type of therapeutic mud are known on the coast of the Sea of Japan and the Sea of Okhotsk in the areas of development of accumulative and abrasion-accumulative shores. It is shown that muds are similar in composition and medicinal properties, and their waters are chloride sodium-magnesium, with salinity ranging from brackish to 42 g/dm3. Geologically, these accumulations are confined to sedimentary basins, promising for oil, gas, methane-bearing coals, mostly flooded by the sea. In the contact zone of their subaerial and submarine areas at the bottom of lagoons and bays, centers of discharge of groundwater and hydrocarbon gases are formed, which participate in the sulfate reduction reaction with the sulfate of sea waters. The fact of the leading role of this process in the formation of modern therapeutic muds is confirmed by material obtained in areas of widespread sulfide peloids at the bottom of the Black Sea. It can be assumed that subaerial areas, possibly the oil and gas bearing East Siberian, Chukchi, Anadyr and other sedimentary basins, are promising in relation to the discovery of new accumulations of therapeutic sulfide-silt muds. In carrying out oil and gas prospecting in the waters of the poorly studied northern seas, sulfide silts should be considered an indicator of the oil and gas potential of submarine sedimentary basins.
A.N. VASILTSOVA
Institute of Geography, Russian Academy of Sciences, Moscow, Russia
Keywords: geography of industry, geography of mechanical engineering, world industry, aircraft industry, aircraft production
A comparison is made of two waves of internationalization of the global aviation industry, the first of which took place according to the classical scenario of inter-country cooperation, and the second gave rise to such a form of interaction as the supply chain. The reasons that made it extremely difficult for new participants to enter the industry during the first wave are explained, as well as the opportunities that opened up to them at a new stage and allowed them to dramatically expand the space where the aviation industry is present. The half-century history of filling the aircraft map of the world with new enterprises is considered. Groups of countries whose activity in the aircraft industry falls on different time periods have been identified and cartographically recorded. The modern territorial structure of the industry is analyzed. The comparison of the location of the main aircraft factories relative to the state capitals in two groups of countries with different histories of the industry development is made. A forecast is made, suggesting a reduction in the scale of international cooperation in the aviation industry.
P.L. POPOV, A.A. CHERENEV, O.V. EVSTROPIEVA, A.V. BARDASH
V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: Cisbaikalia, protest electoral behavior, environmental restrictions, amendments to the Constitution of the Russian Federation, ethnic voting, local self-government
This article is devoted to the problem of the conditionality of the results of the All-Russian vote on the issue of approval of amendments to the Constitution of the Russian Federation in the Baikal territories having environmental restrictions on economic activities. The study revealed a heterogeneity of the electoral behavior of the population at the district and regional levels. An analysis of the results of the All-Russian vote made it possible to determine that the level of support for the governmental initiative in the Republic of Buryatia is much higher than in Irkutsk oblast. The main ecological and economic prerequisites for the formation of local positive and negative public consensus regarding amendments to the Constitution of the Russian Federation are considered. Using the example of the Olkhonskii district of Irkutsk oblast where voters did not approve of the proposed amendments to the Constitution of the Russian Federation, it is shown that environmental and socio-economic factors, in aggregate, can prevail over socio-cultural ones and cast doubt on the established stereotypes associated with ethnic voting. It is noted that the increased voter turnout in the Olkhonskii district has become an expression of protest electoral behavior, whereas an increased support for the state initiatives is characteristic for the national formations of Russia in general, and for the ethnically similar municipal districts of the constituent entities of the Russian Federation in the Baikal region in particular. The place of the tourism industry in the economic sector of a district is considered. It was found that tourism, as one of the decisive modern directions of development of the Baikal territories and almost the only source of livelihood for the local population, has a high potential for involving territories, which is significantly limited in the conditions of the central ecological zone of the Baikal natural territory. The perception of the amendments introduced to the Basic Law of the country as a source of further deepening of environmental and economic contradictions, has become the cause of political tension and, as a result, a negative electoral behavior.
E.G. KOLOMYTS1, A.K. CHERKASHIN2 1Pushchino Science Center, Russian Academy of Sciences, Institute of Basic Biological Problems, Pushchino, Russia 2V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: Landscape-zonal geospace, factor-attribute space, polysystem stratification, models of the landscape organization, types of landscape connections, territory of the Volga basin
Polysystem analysis procedures are revealed in the unity of mathematical, statistical and logical methods of spatial data processing for studying landscape-zonal geospace by using the Volga basin territory as an example. We proceed from L.S. Berg’s conceptual position about the zonal conditionality of the features of the geographical landscape, which is expressed in the ratio of background (zonal) conditions and local (zonal) factors and characteristics of natural components, the interaction of which unites them into a landscape and zonal whole. On the basis of cartographic material, regional features of the influence of the geographic environment on the formation of the areas of groups of landscape species on the territory and in the system of factor spaces and fields with a spatial framework of the organization of landscape geosystems are revealed. The methodology of polysystem analysis is based on the procedures of stratification of holistic formation into many non-intersecting system layers (monosystems), the study of each of which is carried out independently by special methods of specific theories that model earthly reality in special terms. Three layers-types of a theoretical explanation of the connectivity of groups of landscape species have been identified: a functional model of the “attribute-attribute” relationship, a model of object-typological differentiation of the “object-object” territory, and a cluster taxonomic “object-attribute” model. Based on mathematical relationships, the functions of background, frame, landscape-typological and process components of the territorial diversity of the natural environment are determined.
Ya.O. LEBEDEV1,2,3, R.V. GORBUNOV4,2,3, T.Yu. GORBUNOVA4,2,3,5, A.V. DRYGVAL1,2,3, A.N. KUZNETSOV2,3, S.P. KUZNETSOVA2,3, VAN THINH NGUYEN2, N.I. BOBKO4, S.V. KAPRANOV4
a:2:{s:4:"TEXT";s:562:"1Moscow Representative Office, A.O. Kovalevsky Institute of Biology of the Southern Seas, Russian Academy of Sciences, Moscow, Russia 2Joint Russian-Vietnamese Tropical Research and Technology Center, Hanoi, Vietnam 3A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia 4A.O. Kovalevsky Institute of Biology of the Southern Seas, Russian Academy of Sciences, Sevastopol, Russia 5Рeoples’ Friendship University of Russia (RUDN University), Moscow, Russia";s:4:"TYPE";s:4:"html";}
Keywords: twigs and leaves debris, ash content, geochemical migration, heavy metals, geochemical catena
The paper presents the study’s results of ash content of twigs and leaves debris from forest plants of primary mid-mountain tropical forests of Сentral Vietnam (Bidoup Nui Ba National Park) in order to identify and clarify the elements that enter the soil during their decomposition. A difference in the ratio of twigs and leaves debris in mortmass samples collected in different landscape conditions is shown. At the same time, the influence of periodical and stagnant moisture conditions on the conduct of migratory soil processes is considered. The sampling points of the twigs and leaves debris correspond to the locations of the soil catena within the structural ridge, its top, slope and foothill. This allows us to relate the results obtained on the elemental composition of the twigs and leaves debris to the geochemical migration of chemical elements in different geochemical landscape conditions, from automorphic to accumulative. An attempt has been made to establish the volumes of matter migrating from the mortmass into the soil together with the aqueous solution. Differences in the accumulation of ash elements in the twigs and leaves debris depending on the position in different landscape conditions are revealed. The composition of elements entering the soil with twigs and leaves debris and involved in geochemical migration is established, and the contribution of leaves and twigs debris to the accumulation and migration of elements under different moisture conditions is evaluated. A dependence of geochemical migration processes on the position of the elementary geochemical landscape facies in the catena is pointed out, which manifests itself in a change not only in the total ash content of the twigs and leaves debris, but also in the ratio of ash content of twigs debris to that of leaves debris.
M. SAIFULLAH1,2, ZHIJIA LI3, SHIYIN LIU1, M. ZAMAN4, M. ADNAN1, Sh. MUHAMMAD1,5, WU KUNPENG1, YI YING1, S. HASHIM2 1Institute of International Rivers and Eco-Security, Yunnan University, Kunming, China 2Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan 3College of Hydrology and Water Resources, Hohai University, Nanjing, China 4University of Agriculture, Faisalabad, Pakistan 5International Centre for Integrated Mountain Development (ICIMOD), Kathmandu, Nepal
Keywords: agricultural land-use, SWAT model, semi-arid basin, river discharge, water balance
Land-use has considerable influences on runoff in the semi-arid basin of the Yellow River. Assessing the impacts of land-use changes on runoff characteristics is a vital role for water resources managers. The goal of this study is to evaluate the land-use change impacts on water resources by using the Soil and Water Assessment Tool (SWAT) model. This assessment is needed for a rational organization of water economy activity in the country. Considerable land-use changes have been noticed in the study area. The conversion of land-use to urban land causes uncertainty of parameters in the SWAT model. The results obtained indicate that the SWAT model can be used successfully to assess the impacts of land-use variability on water resources of the study basin. The findings of this research could provide an important reference for soil and water conservation and eco-hydrology of the river basin.
The geomorphological and topographic landscapes of Yazd (Iran) are considered, the study of which is effective not only for the dispersal or selection of this or that human activity, but also represents one of the effective factors in the formation of physical structures of spatial constructions. It is revealed that the analysis of urbanization can be influenced by the conceptualization of phenomenology, because from this point of view the basis of human settlement development is primarily a spatial identity. According to the theory of «lakes of the 4th period of urban civilization in Iran», lakes are considered as the components of urbanism in Iran that form the identity. The present study is intended to complement other geomorphological studies in this area by focusing on the Lake Yazd Lake located in the large Yazd-Meybod-Siyahkuh drainage basin. The work is based on a set of archaeological, geomorphological, sedimentological, space and syntax studies as well as on field data. It is shown that there are separate lakes in the Yazd-Meybod-Siyahkuh watershed, one of which is Lake Yazd. It is established that during the glacial period the lakes merged and ended up in the Siahkuh desert. It is concluded that large cities of Yazd province (Yazd, Meybod and Erdekan) owe their urbanism to the spatial identity, namely the existence of these lakes, while the spatial indeterminacy of smaller cities (Islamabad (Farasha), Taft, Hezrabad and Mehriz)) depends on the water-ice equilibrium line.
I.A. BELOZERTSEVA, N.V. VLASOVA, I.B. VOROBYOVA
V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: geochemistry of landscapes, geography of soils, Siberia, history of science, stationary research
Over more than 60 years of research, the Institute of Geography SB RAS has developed a scientific landscape-geochemical school of experimental study of territories at both regional and local levels, the founder of which was V.A. Snytko. The contribution of experimental monitoring studies of the material component of geosystems to knowledge of their dynamics and evolution in natural and anthropogenic disturbed conditions is considered. It is shown that the uniqueness of the Irkutsk landscape and geochemical school consists not only in the clearly pronounced geographical aspect of its development, but also in the ecological and biotic aspect. When summarizing the experience of landscape-geochemical and soil-geographical studies in Siberia, their important role in providing information for complex physical geography, and in the differentiated assessment of the territory on a material basis is highlighted.
