bluuebunny/crossref_metadata_2025 huggingface dataset:
Concept of intelligent system for controlling regenerative braking and using recovery energy
Authors: Vilgelm Alexander , Nikiforov Mikhail , Cheremisin Vasily
Published: November 2018

The issue of increasing the level of electrical energy recovered by the electric rolling stock and the efficiency of its use at the electrified sections of railways of JSC “Russian Railways” is still topical at present. This issue is considered today in the context of increasing the efficiency of the use of traction rolling stock. Increasing the energy efficiency of the transportation process by increasing the efficiency of recovery can be achieved both by the implementation of organizational decisions and through the introduction of additional equipment in the traction power supply system, for example, installation of reversible converters at traction substations or power storage devices on electric rolling stock and in the system of traction power supply, as well as other technical means, changing the parameters of the operation of sections with mandatory provision of the operability of the regenerative braking systems in the electric rolling stock. To assist in the reasoned adoption of similar and other managerial decisions, it is advisable to create an intelligent system for controlling the processes of applying regenerative braking and using recovery energy. This paper briefly reviews the main results of scientific research on the efficiency of recovery, suggests a mechanism for adapting the methods developed earlier to the system for controlling energy efficiency of recovery processes at the sections of railways.
Experimental study of horizontal impact forces acting on equipment of thick sheet rolling stands during rolling
Authors: Ishchenko Anatoliy , Artiukh Viktor , Mazur Vladlen , Calimgareeva Albina , Gusarova Miroslava
Published: November 2018

Technical aspects, methods and results of experimental studies of reversing rolling stands details horizontal accelerations of thick sheet rolling mills 3000 and 3600 are shown. Sequence of horizontal movements of bottom work roll with chocks in windows of housings during normal metal-in, steady rolling and metal-out is given. Usage of obtained experimental data and calculation of horizontal forces of work rolls chocks impacts against housings provided execution of stress calculations of technical solutions for increase of rolling stands durability.
Possibilities of diagnosing the condition of contact wire in terms of thermal wear
Authors: Klimenko Sergey , Li Vladimir
Published: November 2018

The paper considers the negative consequences of thermal softening of the contact wire material under the action of an electric arc, which is thermal wear. In order to determine the degree of softening of the contact wire in real time, the methodology for assessing the condition of the contact wire of electrified railways by the value of thermal wear is presented. The presented method is based on the criterial approach. The criteria for softening the material of the wire and the transition of the material to the liquid state are introduced. By comparing the amount of heat entering the wire in the event of an electric arc (with these criteria), the contact wire is diagnosed in terms of thermal wear. Calculations have been made using the proposed method; graphical dependences of the amount of heat entering the wire element on the current intensity of the electric arc for various times of its influence on the contact wire are constructed. A device for diagnosing the condition of the contact wire in terms of the amount of thermal wear is proposed, designed to record the place of occurrence of the electric arc, to collect and transmit the necessary initial data. The operating principle of the device is described and its structural diagram is given. The use of the method for assessing the condition of the contact wire in terms of the amount of thermal wear and the diagnostic device will make it possible to quantify the degree of thermal softening of the contact wire material in order to further determine its residual life.
Development of “digital substation” technology for power supply of railways
Authors: Tryapkin Evgeny , Ignatenko Ivan , Keino Maxim
Published: November 2018

The paper considers the application of the “Digital Railway” project at the traction substation. The “Digital Railway” project should become a centralized system uniting the programs for the control of railway elements. In the traction power supply system, the application of digital technologies is often understood as the application of data transfer protocols of the International Energy Commission “IEC 61850”. The substations that switched to this information protocol are usually called “digital”. An attempt to introduce the “digital substation” technology only by completing a set of corresponding equipment can give a negative result of its application. The efficiency achieved through the technical upgrading of equipment (reduction of losses for own needs, reduction of electromagnetic influence, reduction of analog signal input channels, reduction in the number of cable products used, and improvement of the measurement accuracy class) may not be sufficient to pay for the project. The qualitative integration of all involved services in a single information process of monitoring and controlling the digital substation will increase the efficiency of its application. As a positive experience when considering the use of digital technologies in traction power supply systems, one can cite the Automated system for monitoring the railway transport infrastructure developed and implemented by the staff of the Far Eastern State Transport University at a number of traction substations of the Far Eastern operating domain and at the 2ES5K “Ermak” electric locomotive. In addition, this system already has a support of IEC 61850 protocols.
Concept of development of geo-information complex of electrical distribution networks of railway junction
Authors: Каshtanov Alexey , Sidorova Elena , Ananieva Nadezda
Published: November 2018

The paper considers one of the directions for the innovative development of a non-traction power supply system for railway transport by developing an electronic application that provides for the construction of a geo-information model of the complex of electrical distribution networks of a railway junction. The description of the basic principles of construction of the model of electrical distribution networks, the architecture of the developed complex and its functional capabilities is given.
Logistical organization of shipments in the context of interaction of various modes of transport
Authors: Afanasev Mikhail , Filatov Vladimir , Myshovskaya Lyudmila , Gusev Valery
Published: November 2018

The paper represents researches in the field of logistical processes in the context of interaction of various transport modes. The characteristics of forms of shipments’ logistical organization in railroad and water communications were defined that differ from the existing ones by the performed functions and types of operators. This allows describing more precisely the organizational forms of interaction. The authors have developed an algorithm for managing operational activities in the logistics center, based on the interconnection of flows within it and coordination of the participant interaction in supply chains. The proposed methodological recommendations on the economic justification of the logistics center, which consist in the organizational support structure, allow providing a differentiated approach to the planning of operations for processing the flow according to the composition of the logistics chain.
Structural components of space as a component of logistic
Authors: Koroleva Elena , Makashina Irina , Filatova Evgeniya , Sokolov Sergei
Published: November 2018

In this article the author's interpretation of the concept of transport space is offered, its brief characteristic is given. The basic features of the transport space and evidence of the existence of its variable hierarchy that allows observe the transport space at different levels of specificity, are specified. It is shown that freight forwarding can be considered as one of the subspaces of the transport space. It is proved that one of the main requirements for the development of this component should be the requirement to implement the maximum possible information conductivity of all its elements and links, and, therefore, the maximum interest of all its participants. An important role in the study of the transport process has been formulated. The described technique displays all the iterative components of the transport aspect.
Database problems of maritime transport industry on high load platform
Authors: Sokolov Sergey , Glebov Nikolay , Novoselov Roman , Chernyi Sergei
Published: November 2018

The article says about distributed and high load systems, common problems and common instructions for solving such problems as denormalization, replication and sharding of transport and maritime aspects. The analysis of strengths and weaknesses of technology for the transport field of activity was carried out. A fragment of the code for sampling optimization is given. Conclusions about the global use of industry technology are made. When your current infrastructure starts to show the first signs that it is no longer cope with the load and if you have a 128 MB VPS - for you, it can be 10 requests per second. For corporations, it can be 10,000 requests. There is a need for scaling and optimizing the infrastructure. Maritime office needs a good monitoring system. It will help determine the very moment when it's time to scale. Stable systems for monitoring and tracking server performance trends: Munin, Zabbix, Nagios. What usually happens when the high load point is approached: slow or infinite loading of pages; random errors; broken connections from the Web server; partial loading of content (for example, there is no part of the image), and a decrease in audience activity. This direction is very modern and promising for the transport industry.
Essential terms of the contract of carriage of goods
Authors: Akhmetshin Elvir , Kovalenko Kseniya
Published: November 2018

The specifics of the contract of carriage of goods and its difference from other types of contracts used in the sale of goods and services are considered. Application of the contract of carriage of goods for the regulation of large-scale and long-term relations, and also relations between the branches of the economy and the regions of the country are considered. This is of practical importance and is necessary due to the fact that the specifically dedicated norms are applied to each contract along with the norms common to all sales contracts. At the same time, the legal characteristic of economic contract depends not only on the name assigned to it by the parties but also on those rights and obligations that the parties have determined in the contract. However, the functions performed and the role of each of the types of transport contracts cannot be unambiguous. In the article, the factors affecting the transport service of international business transactions are considered.
Modeling and optimization of the decision- making process in the transport system
Authors: Mochalin Mihail , Mochalin Sergey , Levkin Grigory , Kasper Mariya
Published: November 2018

The article deals with the issue of constructing an intellectual system for managing the transport system for the delivery of goods by road in cities. The authors develop the algorithm for constructing schedule the work of all participants of the transport system. It can be used to build an operational plan for the delivery of goods and the subsequent management of the transport system.
Examples of complex measures to improve water exchange in marina
Authors: Dreizis Yuriy
Published: November 2018

The modeling of the marina and coastal structures near the Anapa city on Black sea coast of Russia have been carried out. The optimal configuration of the protected breakwaters and other hydrotechnical struc- tures are chosen for protecting of the marina area in the Anapa region. This configuration protect the marina from incoming waves impact and guaran- tee the need water exchange. A flow, induced by breaking wave, is consid- ered as a main factor of the water exchange. Represented results of re- searches and the variant of engineering decision in sea coastal zone is pos- sible to consider as attempt of management by coastal processes on rather complex sites of the coast with the joint decision about engineering re- quirements of an object, management of the water quality in the coastal zone of the sea and choice of optimum variants with the least of influence on an environment.
Evaluation of personnel development system based on the example of a transport company
Authors: Makovetskaya Elena , Sumachev Aleksey
Published: November 2018

Each company seeks to find new resources to maintain the leading position in the market. One of such resources is the personnel development system, which allows maximizing and increasing the labor potential of the company's employees. Personnel development system is one of the main components of personnel management activities, which contributes to the formation of a team with high abilities and strong motivation to fulfill the tasks facing the company. Development and training of personnel helps to match the level of professional competence of employees to the requirements of the developing market.
Upgrading technological processes of operating the railway infrastructure facilities
Authors: Apattsev Vladimir , Aksenov Vladimir , Zavyalov Anton
Published: November 2018

The analysis of incidents in rail transport shows that the main reason for this is erroneous human actions. In the system "a person - a technical system - a production environment" a person is the "weakest link", determining the reliability and safety of the system functioning. Most incidents on the railway infrastructure occur at the stage of its facilities operation because of relevant technological processes poor-quality implementation. The article presents a method for upgrading technological processes of railway infrastructure facilities operation, the implementation of which allows to identify the most critical technological processes and to reduce the influence of the human factor, thereby increasing the reliability and safety of the transportation process.
Property rights to transport: regulatory issues
Authors: Semeryanova Nina , Fedorenko Olga , Kopytova Anna
Published: November 2018

Applicability of the issue under research is preconditioned by the fact that Russian property right does not meet modern realities; lack of proper regulation raises practical problems of law enforcement and does not guarantee the stability of civil circulation in this area of legal relations. The purpose of the article is to actualize the problematic issues of property law, as the modernization of civil legislation cannot be completed without proper reforming of property right and other proprietary interests. The leading approach to research into this issue is the analysis of civil legislation, the Concept of the development of civil legislation and the draft of Russian Federal Law, which makes it possible to identify the problems of regulating property-legal relations and search for the possibilities for their subsequent resolution. The current usage of limited property rights is significantly difficult. That problem exists due to the lack of guaranteed protection of the owners' rights to other people's things. As a result, there are doubts in the possibility of realizing of the owners' rights without prejudice to their interests. The bearer of limited property rights must be sure of the correctness of his actions and the correct understanding of content of the norm. This is why the right to someone’s things should be guaranteed. The completed analysis can contribute to the protection of the rights and interests of property owners and people owning other people's property on limited property rights.
Justification of the methodological approach to formation of the parties of innovation activities in holdings
Authors: Lukmanova Inessa , Sizova Evgeniya , Zhutaeva Evgeniya , Mironova Olga
Published: November 2018

The paper presents the problematic area of the formation of the parties of innovation activities in holdings and its methodological justification. The objective preconditions for differentiating intersubject interactions as a part of innovation activity with the participation of holdings are considered. Features of the formation of innovation strategies and goal-setting mechanisms are structured; their features in large enterprises are emphasized. The importance of determining the optimal parties of the innovation network as a factor of increasing the efficiency of implementation of innovation activity is substantiated. The external and internal environments of the holding are considered as sources of attracting participants of innovation activity. Features of the procedure for selecting the structure of innovation activity, complicated by the conditions of multi- project environment, are presented. Positive effects from the introduction of the scientific approach to the determination of the parties of innovation activity were revealed.
Analysis of methods to increase the efficiency of ship refrigeration plants
Authors: Ovcharenko Igor , Yenivatov Valeriy , Vyngra Alexei
Published: November 2018

The review of the applicable methods for increasing the efficiency of ship refrigeration plants is made. For the presented methods, such as refrigerant subcooling and automatic control of compressors in refrigeration plant, the expediency of application is discussed on the assumption of marine operational conditions and using R22 and R717 refrigerants.
Development of transport infrastructure in modern megalopolises
Authors: Mottaeva Angela , Vasilyeva Elena
Published: November 2018

The features of transport infrastructure of megalopolises are systematized in the article. The concept of the infrastructure development index is defined, its components are considered. The level of the transport infrastructure development in the largest megalopolises of Russia – Moscow and St. Petersburg is analysed, their place among the megalopolises of the world, according to the standard criteria, is presented. The research is based on statistical and analytical data from 2010 till 2018. The main directions of strategic development of transport infrastructure in the Russian megalopolises and expected indicators till 2030 are also considered. The authors point out the problems of road-and-transport infrastructure in megalopolises, but on the other hand they reveal the advantages of megalopolises, which contribute to the development of their transport complexes.
Modeling the operation of road pavement during the thawing of soil in the subgrade of highways
Authors: Isakov Aleksandr , Razuvaev Denis , Gudkova Irina , Chakhlov Michael
Published: November 2018

The solution for modeling the operation of road pavement during the thawing of soil in the subgrade of highways is proposed in this work. A model for layer-by-layer thawing of soil in the subgrade of highways was developed and illustrated, including the stage of modeling the change in the strength of the road structure during the thawing of soil, determining the dependence of the structural strength on the depth of soil thawing, thermophysical modeling of the process of freezing/thawing of soil in the subgrade using a software complex “Freeze-1” developed by the SSTU with determination of the dependence of the structural strength on time.
Vehicle-bridge interaction system
Authors: Provornaya Daria , Glushkov Sergey
Published: November 2018

One of the problems in high-speed railways is the influence and vibrations of bridges caused by moving trains. This problem significantly differs from the problems of road bridges for the following reasons. Firstly, the loads caused by the moving train on the bridge are repeated in nature, as a consecutively rotating loads (wheel), implying that certain frequencies will be caused on the bridge during the passage of the train. In contrast, the loads implied on the road are random in nature, expressed through wheel loads and the distance between the wheels. Secondly, high-speed trains can move at a speed much higher than vehicles moving along the road, which makes it possible for the excitation frequency to coincide with the oscillation frequencies of the bridge, which leads to the so-called resonance effect. Whenever the resonance condition is reached, the reaction of the bridge will be constantly amplified, since there are heavy moving loads passing through the bridge. This effect could hardly be observed on road bridges. Thirdly, the mass ratio of vehicles on the bridge is usually larger due to the fact that the train consists of several coupled cars and the railway track is relatively narrow, it has no more than two tracks in most cases. In contrast, a road bridge may be so large that it can afford four or more lanes for vehicles moving in the opposite direction. For this reason, the interaction between moving vehicles causes a greater reaction for the road bridge than for the railways.
Design of track structure for corridors of heavy- train traffic
Authors: Kosenko Sergey , Akimov Sergey
Published: November 2018

The topical issues of the development of heavy-train traffic along the Central Siberian Main from the “Altaiskaya” station to the “Irtyshskoe” station of the West Siberian Railway are considered in this paper. For this purpose, the rational design of the track structure for increased axial loads and side forces was selected and analyzed, and measures to expand the operating domain of the continuous welded rail track by improving the design of sleepers and intermediate rail fasteners without changing the plan and profile of the track were considered. Adjusting the track gauge by surface and line is a critical task. The paper discusses the issues of ensuring the widening of the track gauge in curved sections with a radius of less than 350 m as one of the constraints to the development of the operating domain of the continuous welded rail track on the railways of JSC “Russian Railways” and on the West Siberian Railway. Two main ways of ensuring the widening of the track gauge are considered: by changing the structure of sleepers and by means of additional structural elements of intermediate rail fastenings, or a combination of both. This ensures the smoothness when guiding the rolling stock in the curve section of the track, improves the interaction in the wheel-rail system, reduces wear, and complies with requirements of existing regulatory documents. All this reduces the dynamic load on the track, including the subgrade, and extends the service life of the track structure in conditions of heavy-train traffic.
Fire retardant for expansion and linear joints in buildings and tunnels
Authors: Prusakov Vasiliy , Gravit Marina , Simonenko Yana , Minnullina Anna , Artyukhina Alexandra
Published: November 2018

The review of fire-prevention barriers of deformation seams both foreign, and domestic manufacturers is provided in article. It is shown that the fire-prevention barriers which are specially developed for application in deformation seams, guaranteed working at compression, stretching and shift of a seam are applied to protection of deformation seams at the fire it is established that production of innovative fireproof materials is one of the main objectives of fire safety, it and ways of consecutive transformation of the idea to the goods passing stages of researches, design developments, productions and realization in projects of civil and industrial function of buildings. The prime purpose – to pick up the complex decision providing the maximum satisfaction of requirements when performing fireproof works on protection of a deformation seam at impact of the fire.
Efficiency of Using Tuned Mass Damper to Reduce Damage after Strong Earthquakes
Authors: Benin Andrei , Uzdin Alexander , Nesterova Olga
Published: November 2018

The efficiency of applying tuned mass damper is substantiated for reducing the damageability of structures under strong earthquakes. Two models of structure damage accumulation are considered. The first model is elastoplastic one, the damage degree of the model being determined by the work of plastic deformation forces. The second model is a model with degrading rigidity the damage degree of the model is connected with the development of cracks and is determined by the maximum displacement of the structure in its loading history. For the first type of nonlinearity, i.e. the first model there is an amplitude-frequency characteristic and the optimum tuning of the mass damper corresponds to the maximum of this characteristic. For the second model of accumulation of damages there is no frequency response, therefore the mass damper tuning obtained with harmonic action on the elastic system was used. Calculations of the system with mass damper and without it using earthquake accelerograms have been carried out. Accelerograms, the most unfavorable in terms of the spectral composition for the structures under consideration, were chosen taking into account peak accelerations and energy characteristics of the seismic action. It has been established for elastoplastic systems that tuned mass damper reduces the time of the structure being in plastic stage and the work of plastic deformation forces. For systems with degrading stiffness tuned mass damper reduces the maximum movement of the system in its loading history.
Estimation of the influence of a defect on the operational suitability of a pipeline
Authors: Tarasenko A.A. , Chepur P.V. , Gruchenkova A.A.
Published: November 2018

A finite-element model of a pipe header with a defect in the metal wall was created in the ANSYS software complex. The boundary conditions consider the hinging of the ends of the section from linear displacements. The calculation is based on the procedure of the allowable conditional elastic stresses. Values of equivalent stresses arising in the defective pipeline from the operational loads are obtained. Analysis of the obtained stresses in comparison with the allowable values is given based on the calculated resistance of steel. It is established that a dent in the pipeline causes a local stress perturbation. Thus, an increase in equivalent stresses in the region of the maximum depth of the dent amounted to 1.3% in comparison to the vicinity of the defect. Maximum values of membrane, tangential, and equivalent stresses do not exceed the design resistance. A conclusion is drawn on the influence of the dent-type defect on the operational suitability of the pipeline under study.
Accident at river-crossing underwater oil pipeline
Authors: Titova Tamila , Akhtyamov Rasul , Nasyrova Elina , Elizaryev Alexey
Published: November 2018

The aim of this article is to present an approach enabling to define the flame spread velocity at spill fire on the river, taking into account the wind speed. Due to constant oil supply from the pipeline during the leakage, an oil slick will increase until its borders reach river banks. Formulas for determining the main parameters of oil spill on the river in case of an accident at underwater oil pipeline were suggested. The formulas include the initial data determined in the field, for instance, flow and wind speed, as well as water temperature. An example of the change of oil slick parameters on the river was demonstrated. The spread rate of spilled oil and the flame spread speed were calculated. It was shown that on narrow rivers, an oil slick takes the form of a river bed within a few minutes and moves in the direction of the flow. Determination of oil spill parameters given in the study is sufficient for accident response implementation: - spread rate of spilled oil allows for distance calculation in order to install oil booms; - flame spread speed in conjunction with the oil slick size will make it possible to calculate the fire extinguishing means. The obtained results, undoubtedly, require testing in experimental conditions, which is the purpose of further research.
Free oscillations of thin-walled bimetallic pipelines of large diameter on an elastic foundation
Authors: Sokolov Vladimir , Razov Igor , Koynov Evgeniy
Published: November 2018

In the paper, solutions for a thin-walled bimetallic pipeline are obtained. The frequencies of free oscillations are investigated, taking into account the internal working pressure, the longitudinal compressive force, and the elastic foundation. The solutions were obtained on the basis of a geometrically nonlinear version of the semi-momentum theory of cylindrical shells of the middle bend. The proposed calculations can be used in the nuclear power industry, aviation, and petrochemical industry.
Training of transport industry personnel in the digital economy: the evolution of information educational technology
Authors: Khabarov Valery , Volegzhanina Irina
Published: November 2018

The urgency of the study is stipulated by the problem of professional training of personnel for the leading industries of the material production of the Russian Federation, one of which is the transport industry, in the context of implementation of the digital economy program and the integrated scientific and technological project “Digital Railway”. The nature of knowledge belonging to the intellectual field of the industry is revealed through the synthesis of the humanitarian (associated with man) and formal logical (associated with artificial systems). New requirements make it necessary to refer to modern educational technologies in the e-learning paradigm 3.0. Such technologies are based on knowledge presented in accordance with the international standard ISO/IEC - in the ontology format. In this regard, this paper is aimed at revealing the possibilities of semantic technologies in the development of virtual learning environments for educational organizations in the network structure of sectoral subordination in the open projects model. Development of ontological content is carried out remotely by joint efforts of representatives of the employer and education. FSBEI of Higher Education “Siberian State Transport University” (Novosibirsk) implements an interuniversity project on the development of the multilingual electronic learning environment “Onto.plus” on the basis of new technologies in the format of the digital economy. The proposed educational solution has been tested in the real learning process. Its effectiveness has been proved for the training of future transport industry personnel; the directions of the project development are outlined.
Practical approval of the rating assessment of the budget potential of the territory
Authors: Morunova Galina , Gorbushina Svetlana , Chesnova Olga , Kuzmina Svetlana
Published: November 2018

In the article the authors consider the issues of ensuring sustainable development of territories on the example of municipalities, methods of monitoring and evaluating the rating of a municipality, in particular, investigate the possibility of compiling a comprehensive rating for assessing the budget potential of a territory in order to analyze its impact on sustainable development. The authors also analyze the satisfaction of the population of municipalities with the activities of local authorities, including on the basis of an assessment of budgetary performance indicators. The authors suggest possible directions for applying the approved methodology for rating the sustainable development of municipalities to form a territory development strategy.
Operation of transport companies in terms of the sustainable growth of the region
Authors: Averbukh Roman , Kononova Galina , Tsiganov Vsevolod
Published: November 2018

The article highlights the influence of the regional economic entities on the sustainable growth of the region. The nature of effect of the local conditions on the efficiency of the entrepreneurial activity is determined. The definition of sustainable growth of the region is clarified. Transport organizations are taken as a study subject. The main operational results of transport organizations, that are directly related to the living standards, are identified and classified. The extended algorithm for the correspondence between organizations’ efficiency and growth of the region is developed. Priority factors, that aim to increase the performance of transport companies, are determined. These factors include active use of digital technologies in carriage of passengers and cargo traffic as well as application of principles of behavioral economics in human resource management. Issues of behavioral economics are considered from the standpoint of the problem of growth in labor productivity.
Application of budgeting tools to cut structural imbalances in regional development
Authors: Romanova Natalia , Anisimova Nadezhda , Provotorov Ivan
Published: November 2018

Today priorities in the growth of the regions and the need to reduce imbalances in its development requires to work out the theoretical and methodological approach to the feasibility of financial support of the regions and to the study of applications of budgeting tools in order to eliminate the asymmetry and to improve investment activity of municipalities. The authors studied the causes and the sequences of uneven development of territories; the experience to balance the economic growth of Voronezh region was analyzed. There were given recommendations on calculating the level of co-financing of the expenditure commitments of the municipality from the regional budget and illustrated the efficiency of applying budgeting tools to a specific facility in one of the regions.
Impact of mathematical theory of exchange on national economic growth
Authors: Novokshonova Elena , Pivovarova Marina , Tyurnin Vladimir
Published: November 2018

The paper presents the economic and mathematical theories of exchange by W.S. Jevons, L. Walras, J.E. Stiglitz, B. Holmström, and others. Theories of exchange are classified into classical (J.B. Say), neoclassical (A. Marshall), contractual (B. Holmström), natural scientific (V. Pareto), statistical. Mathematical models of exchange allow deepening the concept of competition. They show competition from the interaction of producers and the resulting uncertainty of exchange. It is shown that the emphasis on exchange to the detriment of production or, conversely, underestimation of exchange in economic regulation leads to a slowdown in economic growth. Research methods: abstraction, analysis and synthesis, the method of comparative descriptive analysis, economic and mathematical analysis.
Numerical investigation for convective heat transfer and friction factor under pulsating flow conditions
Authors: Aslan Erman , Ozsaban Mert , Ozcelik Guven , Guven Hasan Riza
Published: November 2018

For pulsating flow, the behaviours of the convective heat transfer and friction factor for a periodic corrugated channel are investigated numerically. The finite volume method is used in the numerical study. Three different Reynolds Averaged Numerical Simulation based turbulence models, namely the k-ω model, the Shear Stress Transport (SST) model and the transition SST model are used and compared. The results are also compared with the previous experiments for non-pulsating flow. Analyses are conducted for air flow through a corrugated channel which has sharp corrugation peaks with an inclination angle of 30° and a 5mm minimum channel height. Reynolds number is changed in the range 6294 to 7380, while keeping the Prandtl number constant at 0.70. A sinusoidal pulsatile flow condition which is F=400 and uA*=0.5 is used. Variations of the Nusselt number and the friction factor with the Reynolds number are studied. Non-pulsating flow results and pulsating flow results are compared with each other.
Study of a hydraulic system converting energy from sea waves near the coast
Authors: Barbarelli Silvio , Amelio Mario , Florio Gaetano , Scornaienchi Nino Michele
Published: November 2018

This paper proposes a system able to recover energy from sea waves. The system is made up essentially of a floating structure, connected to a piston pump. The pump, constrained to move vertically under the action of the waves, pushes water into a reservoir maintained at constant pressure, from which it flows in a Pelton turbine. A methodology was developed for the preliminary sizing of the proposed system. This methodology takes the height of the waves and the pressure of the reservoir as reference parameters and then provides the main geometric data of the machines. A case study developed in the present work, demonstrates the possibility of designing miniaturized components of the system, able anyway to provide acceptable energy output with contained installation costs.
Analysis of heat transfer in a coated bed of an adsorption chiller
Authors: Grabowska Karolina , Sosnowski Marcin , Krzywanski Jaroslaw , Sztekler Karol , Kalawa Wojciech , Zylka Anna , Nowak Wojciech
Published: November 2018

Adsorption chillers can be a promising part of sustainable development concept of the global economy due to the utilization of low grade thermal energy sources for cooling production. Therefore, research aiming at improving their performance i.e. Coefficient of Performance (COP) by optimizing the heat and mass transfer condition in the adsorption beds are crucial. Innovative modification of the sorbent layer structure are proposed in the paper in order to improve the heat transfer characteristics in the heat exchanger boundary layer. The analysis of desorption conditions in the parametric model of a coated adsorption bed construction is presented in the paper. The computational fluid dynamics with conjugate heat transfer analysis are used to determine the crucial input parameters for further analytical calculations. The heat transfer condition in novel coated design and a conventional fixed bed are compared in the paper. The developed computational model consisted of three subdomains representing heating water, heat exchanger material (copper) and sorbent (silica gel).
The application of Picard method in identification of the heat transfer coefficient in flow boiling in a minichannel
Authors: Grabowski Mirosław , Hożejowska Sylwia , Pawińska Anna , Poniewski Mieczysław E.
Published: November 2018

This paper summarizes the procedure of experimental determination of flow boiling heat transfer coefficient in the rectangular minichannel 2 mm wide, 1.8 mm deep and 193 mm long. In this experiment, the basic thermal and flow parameters were measured and the temperature distribution on the foil insulating the heater was recorded using an infrared camera. A high speed video camera observed the vapor patterns forming during the boiling process. The void fraction was determined with the image processing technique. Stationary heat transfer process in the insulating foil, the heater and the flowing liquid was described using two-dimensional Laplace’s equation (for the foil), the Poisson equation (for the heater) and energy equation (for the liquid) – all complemented with an appropriate system of boundary conditions. The system of the differential equations with adopted boundary conditions gives the three consecutive inverse problems in elements of the test section containing minichanel. Trefftz method was used to determine two dimensional temperature distribution of the foil and the heater. The liquid temperature was calculated using the Picard-Trefftz method. The values of the experimentally obtained heat transfer coefficients with the values of these coefficients calculated on the basis of correlations known from the literature were also compared.
Turbulence models impact on the flow and thermal analyses of jet impingement
Authors: Kura Tomasz , Fornalik-Wajs Elżbieta , Wajs Jan , Kenjeres Sasa
Published: November 2018

Accurate numerical reconstruction of heat and mass transfer processes in particular applications, such a jet impingement, is difficult to obtain even with the use of modern computational methods. In the proposed paper, the flow and thermal phenomena occurring during single minijet impingement on the flat, concave and convex, heated surfaces were considered. Problem of impingement on non-flat surface, still not common and purely described in the literature, can be of big importance in engineering applications, such as the heat exchangers. Numerical analyses, based on the mass, momentum and energy conservation laws, were conducted with the OpenFOAM software. Focus was placed on the proper model construction, in which turbulence and boundary layer modelling was crucial, due to their significance in the heat transfer processes. Analysis of results obtained by RANS models focused mostly on the comparison of turbulent and hydrodynamics parameters.
Thermal and water transfer in cementitious porous medium: thermal building and durability
Authors: Ma Xiaoyan , Benboudjema Farid , Bennacer Rachid
Published: November 2018

Cementitious materials are typical porous medium, which are widely used in civil engineering and thermal buildings. The thermal and hydrate properties of the material are fundamental to predict accurately the energy needs and the reliable duration of the structures in a long term. Due to the complicated coupling, the thermal capacity, conductivity and source term in energy equation are affected by the humidity distribution and the microstructure evolution of the porous materials. The coupling relation of thermal and hydrate properties are summarized in this work, the coupled drying model is discussed, and the experiment is performed to verify the simulation results for RH (Relative humidity) and ML (Mass loss). Two approaches are adopted to estimate the humidity/water content profile in the porous medium and to analyse the temperature effect. In addition, the equivalent hydrate capacity and conductivity are identified as function of humidity. The significance of this work lies in predicting the energy demand, the long-term thermal behaviour, taking into account the change of the thermal cementitious materials properties during their service time. Such inner structure is consequence of the system durability where the temperature, water content and humidity will act on the cracks settling within the material.
A thermal parametric study of non-evaporative spray cooling process
Authors: Otmani Abdessalam , Mzad Hocine , Bey Kamel
Published: November 2018

Ordinary water spray cooling is connected with very high temperatures where heat transfer during evaporation plays a key role. However, during cooling without phase change, the behaviour of the spray cooling parameters is rarely considered. The purpose of this paper is to study the influence of spray hydrodynamic parameters on heat transfer without liquid phase change during the cooling of an aluminium 3003-H18 plate at a temperature of 92 °C. First of all, the flow rate was varied from 0.497 up to 1 l/min. Then, the inlet pressure varied from 0.7 to 2.1 bars. The influence of nozzle-to-target distance is also tested since the simulations were carried out in a wide height range, from 100 mm to 505 mm. The present simulation was achieved using the version 5.2 of COMSOL Multiphysics code.
Numerical analysis of liquid jet impingement cooling of a thermoelectric generator
Authors: Pfeiffelmann Björn , Benim Ali Cemal , Joos Franz
Published: November 2018

Designs of heat exchangers are quite often disconnected to the performance of thermoelectric generators (TEG). In this work, the TEG and the heat exchanger are numerical modelled simultaneously in a computational fluid dynamics (CFD) environment (OpenFOAM) to maximize the output power of the system while minimize the hydraulic power required. A preliminary work was done where the modelling of the heat exchanger, a single laminar slot jet, and the modelling of a 16 element TEG are validated. The considered heat exchanger is a laminar slot jet consists of a linear array of discrete heat sources which accord with the geometry of a thermoelectric generator. The considered 16 element TEG is modelled using the temperature dependent material properties which require a solution of a system of nonlinear differential equations, namely the conservation of energy and the conservation of electric current. The conjugate heat transfer OpenFOAM solver chtMultiRegionFoam is extended by an additional differential equation for the solid region to model the conservation of current. The conservation of energy is expanded by additional source terms based on Peltier/Thomson effect and Joule heat. To simplify the calculation, interface and 1D resistor load boundary conditions are developed and implemented. The heat exchanger and the TEG model, both, are validated by comparisons with measurements, where a good agreement is observed.
The possibility of simplified modelling of radiation heat transfer within a steel porous charge
Authors: Wyczółkowski Rafał , Wyleciał Tomasz , Gała Marek
Published: November 2018

The article refers to the problem of calculating the effective thermal conductivity kef of a steel porous charge. In proposed approach for each heat transfer mechanism, which occurs in the considered medium, the corresponding thermal resistance is assigned. The model values of the kef coefficient were determined twice for the same input data (geometric dimensions, emissivity, temperature, thermal conductivity of steel and gas). The difference between successive calculations depended on the use of two different methods to determine the thermal radiation resistance Rrd. In the first approach the resistance Rrd was calculated using the exact method and in the second approach the simplified, approximate method was used. The discrepancy between the obtained results of kef in both approaches provides the evidence to use the approximate method to determine the resistance Rrd. A bundle of square steel sections were used to demonstrate the challenge. In the exact method, data regarding the temperature distribution within a single profile was used. These data were obtained based on experimental research using a guarded hot plate apparatus. The calculations were performed using a temperature range between 200ºC and 800ºC for two sections: 60×60mm and 80×80mm and three emissivities: 0.5, 0.7 and 0.9.
Numerical investigation of flow distribution in tubular space of fin-and-tube heat exchanger
Authors: Stelmach Tomasz
Published: November 2018

This paper presents the experimental and numerical investigation of flow distribution in the tubular space of cross-flow fin-and-tube heat exchanger. The tube bundle with two rows arranged in staggered formation is considered. A standard heat exchanged manifold, with inlet nozzle pipe located asymmetrically is considered. The outlet nozzle pipe is located in the middle of the outlet manifold. A developed experimental setup allows one to measure volumetric flow rate in heat exchanger tubes using the ultrasonic flowmeters. The measurement results are then compared with CFD simulation in ANSYS CFX code using the SSG Reynolds Stress turbulence model, and a good agreement is found for tube Re numbers varied from 1800 to 3100.