Pub Date : 2023-10-05DOI: 10.20998/2413-4295.2023.03.03
Valerij Yefymenko, Viktor Oleksandrenko, Natalii Kalmykova, Vira Rudenko, Okeksandr Yefimenko
The possibilities and expediency of using fullerene additives and their influence on the tribological properties of modern synthetic aviation oils are analyzed. The method of increasing anti-wear properties of synthetic oils for turbojet aircraft engines Mobil Jet Oil II and Mobil Jet Oil 254 by adding fullerene additive C60 is considered. It is shown that the antiwear properties of synthetic Mobil Jet Oil 254 oil for turbojet aircraft engines exceed more than 5% of Mobil Jet Oil II oil, which, along with other factors, was the reason for the complete transfer of Airbus Helicopters H-145 helicopters to Mobil Jet Oil 254 oil. The increase in the concentration of fullerene additives in oils does not significantly affect the amount of wear of the rolling bearings of the turbine shaft of helicopters, although there is a tendency to decrease the diameter of the wear spot and an increase in the critical load of the transition to seizing. This is explained by the fact that, in contrast to sliding friction, in which the coefficient of friction decreases tenfold due to the possibility of rolling of fullerene molecules on the graphite surface, which is characterized by much lower friction compared to the sliding of graphite surfaces relative to each other due to the higher contact area in the last case. It follows that fullerenes act as micro-rolling bearings that reduce the coefficient of sliding friction. It is assumed that the balls in the rolling bearings may grind fullerenes like ball mills, therefore no significant effect of improving the anti-wear properties of oils when using fullerene additives is observed. It was established that an increase in the concentration of the fullerene additive in oils shifts the critical load to higher values. The use of fullerenes as an anti-wear additive to oils for turbojet engines requires further research and justification.
{"title":"PROSPECTS FOR THE APPLICATION OF FULLERENE ADDITIVES IN MODERN AVIATION OILS","authors":"Valerij Yefymenko, Viktor Oleksandrenko, Natalii Kalmykova, Vira Rudenko, Okeksandr Yefimenko","doi":"10.20998/2413-4295.2023.03.03","DOIUrl":"https://doi.org/10.20998/2413-4295.2023.03.03","url":null,"abstract":"The possibilities and expediency of using fullerene additives and their influence on the tribological properties of modern synthetic aviation oils are analyzed. The method of increasing anti-wear properties of synthetic oils for turbojet aircraft engines Mobil Jet Oil II and Mobil Jet Oil 254 by adding fullerene additive C60 is considered. It is shown that the antiwear properties of synthetic Mobil Jet Oil 254 oil for turbojet aircraft engines exceed more than 5% of Mobil Jet Oil II oil, which, along with other factors, was the reason for the complete transfer of Airbus Helicopters H-145 helicopters to Mobil Jet Oil 254 oil. The increase in the concentration of fullerene additives in oils does not significantly affect the amount of wear of the rolling bearings of the turbine shaft of helicopters, although there is a tendency to decrease the diameter of the wear spot and an increase in the critical load of the transition to seizing. This is explained by the fact that, in contrast to sliding friction, in which the coefficient of friction decreases tenfold due to the possibility of rolling of fullerene molecules on the graphite surface, which is characterized by much lower friction compared to the sliding of graphite surfaces relative to each other due to the higher contact area in the last case. It follows that fullerenes act as micro-rolling bearings that reduce the coefficient of sliding friction. It is assumed that the balls in the rolling bearings may grind fullerenes like ball mills, therefore no significant effect of improving the anti-wear properties of oils when using fullerene additives is observed. It was established that an increase in the concentration of the fullerene additive in oils shifts the critical load to higher values. The use of fullerenes as an anti-wear additive to oils for turbojet engines requires further research and justification.","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135547659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20998/2413-4295.2023.03.04
Andrii Slipchuk
Today, the world's leading enterprises engaged in the manufacture of gear wheels increasingly use the Power Skiving method of cutting the gear crown on the wheel. This modern method allows you to process wheels with an external and internal crown, both spur and helical, as well as cut slots on shafts or hubs. This technology combines elements of turning and milling and ensures a very short production time. However, every year this method is increasingly improved, and in terms of its kinematics it is very complex and requires precise calculations. Determining the exact position of the tool and the workpiece at each moment of time is necessary for synchronizing movements during cutting. The principle of building an undeformed chip when cutting an internal straight-tooth crown by the Power Skiving method is shown. Section parameters for chip sections are obtained. They are the basis for modeling and calculating the values of cutting forces, friction, the necessary work that is needed to eliminate the allowance, heat flows that occur during cutting, the intensity of tool heating, temperature and wear of the tool, simulation of oscillations and dynamic processes. Complete information about the size and shape of the sheared layers, their size in different sections of the tooth at each moment of the cutting time is necessary for the description of various interrelated and interdependent deformation and contact processes. The established regularities of their continuous cyclical change during the revolution of the cutting tool are required for a comprehensive reproduction of the processes that occur during the cutting process of the toothed crown. A complex system of grapho-analytical, mathematical and computer modeling of this process has been developed for such a task. Kinematics is taken into account and the patterns of cutting-forming processes are reliably reproduced. The application of the grapho-analytical method of constructing sections for an undeformed chip is presented, which made it possible to establish its geometry and main characteristics, as well as to obtain a 3D model. Adequate models of chip formation are obtained. Quantitative estimates of parameters for slices in the process of Power Skiving are analyzed.
{"title":"SIMULATION OF UNDEFORMED CHIP FORMED DURING CUTTING FOR INTERNAL CROWN TOOTH BY THE \"POWER SKIVING\" METHOD","authors":"Andrii Slipchuk","doi":"10.20998/2413-4295.2023.03.04","DOIUrl":"https://doi.org/10.20998/2413-4295.2023.03.04","url":null,"abstract":"Today, the world's leading enterprises engaged in the manufacture of gear wheels increasingly use the Power Skiving method of cutting the gear crown on the wheel. This modern method allows you to process wheels with an external and internal crown, both spur and helical, as well as cut slots on shafts or hubs. This technology combines elements of turning and milling and ensures a very short production time. However, every year this method is increasingly improved, and in terms of its kinematics it is very complex and requires precise calculations. Determining the exact position of the tool and the workpiece at each moment of time is necessary for synchronizing movements during cutting. The principle of building an undeformed chip when cutting an internal straight-tooth crown by the Power Skiving method is shown. Section parameters for chip sections are obtained. They are the basis for modeling and calculating the values of cutting forces, friction, the necessary work that is needed to eliminate the allowance, heat flows that occur during cutting, the intensity of tool heating, temperature and wear of the tool, simulation of oscillations and dynamic processes. Complete information about the size and shape of the sheared layers, their size in different sections of the tooth at each moment of the cutting time is necessary for the description of various interrelated and interdependent deformation and contact processes. The established regularities of their continuous cyclical change during the revolution of the cutting tool are required for a comprehensive reproduction of the processes that occur during the cutting process of the toothed crown. A complex system of grapho-analytical, mathematical and computer modeling of this process has been developed for such a task. Kinematics is taken into account and the patterns of cutting-forming processes are reliably reproduced. The application of the grapho-analytical method of constructing sections for an undeformed chip is presented, which made it possible to establish its geometry and main characteristics, as well as to obtain a 3D model. Adequate models of chip formation are obtained. Quantitative estimates of parameters for slices in the process of Power Skiving are analyzed.","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135547660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20998/2413-4295.2023.03.05
Bohdan Vorobiov, Serhii Senchenko, Yaroslav Kyrylenko, Yaroslav Likhno, Liu Khan, Yurii Kutovyi
This article presents an approach to integrating computer vision algorithms into the control system of traction electric drives in rail transport. It demonstrates the utilization of computer vision algorithms for calculating linear velocity as an alternative to conventional sensors like wheel odometers, GPS, DGPS and inertial sensors, which may prove ineffective on slippery surfaces and at low speeds. As a result, this article focuses on employing linear velocity as feedback within the control system to enhance power efficiency during starting and stopping and to prevent wheel slip. The electric drive control system has been successfully implemented and tested on a robotics platform designed for simulating dynamic behaviors in real rail transports scenarios. The article details the development process of this robotics platform, which is employed to mimic real-world dynamic conditions in rail transport. The proposed control algorithm for speed estimation is assessed using a specially designed test bench, revealing its capability to predict speed with a relatively high degree of accuracy. Additionally, an optical flow algorithm for velocity estimation is introduced and evaluated through a specially designed test rig, indicating a strong correlation between the predicted vehicle speed and the measurements from precision optical encoders. The study also determines the optimal feature window size for real-time optical flow rate estimation. In summary, this approach exhibits significant potential for accurate speed estimation. Ongoing experiments are being conducted under various real-world conditions, with future research aimed at developing a dependable autonomous system for speed measurement. The integration of modern digital computer vision technologies not only enhances the traction characteristics of electric drives but also extends the capabilities of traction electric drives to meet the rigorous demands of industrial equipment.
{"title":"MEASUREMENT OF LINEAR VELOCITY USING A MOBILE ROBOTIC PLATFORM WITH COMPUTER VISION","authors":"Bohdan Vorobiov, Serhii Senchenko, Yaroslav Kyrylenko, Yaroslav Likhno, Liu Khan, Yurii Kutovyi","doi":"10.20998/2413-4295.2023.03.05","DOIUrl":"https://doi.org/10.20998/2413-4295.2023.03.05","url":null,"abstract":"This article presents an approach to integrating computer vision algorithms into the control system of traction electric drives in rail transport. It demonstrates the utilization of computer vision algorithms for calculating linear velocity as an alternative to conventional sensors like wheel odometers, GPS, DGPS and inertial sensors, which may prove ineffective on slippery surfaces and at low speeds. As a result, this article focuses on employing linear velocity as feedback within the control system to enhance power efficiency during starting and stopping and to prevent wheel slip. The electric drive control system has been successfully implemented and tested on a robotics platform designed for simulating dynamic behaviors in real rail transports scenarios. The article details the development process of this robotics platform, which is employed to mimic real-world dynamic conditions in rail transport. The proposed control algorithm for speed estimation is assessed using a specially designed test bench, revealing its capability to predict speed with a relatively high degree of accuracy. Additionally, an optical flow algorithm for velocity estimation is introduced and evaluated through a specially designed test rig, indicating a strong correlation between the predicted vehicle speed and the measurements from precision optical encoders. The study also determines the optimal feature window size for real-time optical flow rate estimation. In summary, this approach exhibits significant potential for accurate speed estimation. Ongoing experiments are being conducted under various real-world conditions, with future research aimed at developing a dependable autonomous system for speed measurement. The integration of modern digital computer vision technologies not only enhances the traction characteristics of electric drives but also extends the capabilities of traction electric drives to meet the rigorous demands of industrial equipment.","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135547846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20998/2413-4295.2023.03.06
Vadym Krykun, Yuri Homyak, Marharyta Pozniakova
Paper presents a detailed technology of tomographic inspection in the laboratory. Tomographic inspection is a powerful tool for obtaining high-quality three-dimensional images of the internal structure of objects. The advantages of the method are considered, which include the non-destructive nature of the control, high resolution, measurement accuracy, and the ability to detect defects invisible to the human eye. The main attention is paid to the description of the main stages of tomographic inspection, which are recommended to achieve maximum efficiency. Possible errors that may occur during tomographic inspection in the laboratory are highlighted, and ways to eliminate them are provided. The optimal parameters that should be taken into account during tomographic inspection are considered, including the correct choice of tomograph parameters, setting of lighting conditions, and correct positioning of the object under inspection. The process of processing the obtained inspection data is described in detail, which helps to ensure high-quality information analysis. The authors also analyze the feasibility of the control stages, comparing the results obtained at different stages and considering their impact on the final result. This work is a valuable source of information for specialists involved in tomographic control in the laboratory. The described technology and recommendations will help to improve the quality and efficiency of tomographic inspection in their work. The research results presented in this article can improve the inspection process, reduce errors, and detect even the smallest defects in samples. In general, this paper offers a recommended technology for tomographic inspection in the laboratory, taking into account key aspects such as the advantages of the method, inspection stages, error elimination, optimal parameters, object positioning, and data processing. Taking these recommendations into account, specialists will be able to provide more accurate, efficient and reliable tomographic control in their work. Thus, this article will be a valuable addition to the scientific literature in the field of non-destructive testing, will help improve the quality of tomographic testing and promote the development of this important method in the laboratory.
{"title":"RECOMMENDED TECHNOLOGY FOR TOMOGRAPHIC INSPECTION IN THE LABORATORY","authors":"Vadym Krykun, Yuri Homyak, Marharyta Pozniakova","doi":"10.20998/2413-4295.2023.03.06","DOIUrl":"https://doi.org/10.20998/2413-4295.2023.03.06","url":null,"abstract":"Paper presents a detailed technology of tomographic inspection in the laboratory. Tomographic inspection is a powerful tool for obtaining high-quality three-dimensional images of the internal structure of objects. The advantages of the method are considered, which include the non-destructive nature of the control, high resolution, measurement accuracy, and the ability to detect defects invisible to the human eye. The main attention is paid to the description of the main stages of tomographic inspection, which are recommended to achieve maximum efficiency. Possible errors that may occur during tomographic inspection in the laboratory are highlighted, and ways to eliminate them are provided. The optimal parameters that should be taken into account during tomographic inspection are considered, including the correct choice of tomograph parameters, setting of lighting conditions, and correct positioning of the object under inspection. The process of processing the obtained inspection data is described in detail, which helps to ensure high-quality information analysis. The authors also analyze the feasibility of the control stages, comparing the results obtained at different stages and considering their impact on the final result. This work is a valuable source of information for specialists involved in tomographic control in the laboratory. The described technology and recommendations will help to improve the quality and efficiency of tomographic inspection in their work. The research results presented in this article can improve the inspection process, reduce errors, and detect even the smallest defects in samples. In general, this paper offers a recommended technology for tomographic inspection in the laboratory, taking into account key aspects such as the advantages of the method, inspection stages, error elimination, optimal parameters, object positioning, and data processing. Taking these recommendations into account, specialists will be able to provide more accurate, efficient and reliable tomographic control in their work. Thus, this article will be a valuable addition to the scientific literature in the field of non-destructive testing, will help improve the quality of tomographic testing and promote the development of this important method in the laboratory.","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135547663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.20998/2413-4295.2023.03.02
Emmanuel Ettah, Michael E. Ishaje, Kseniia Minakova, Esther Offiong Asuquo, Stephen U. Odey
The evaluation of energy band structure plays a vital role in understanding the electronic properties of materials. This research, we investigate the energy band structure of Half-Heusler alloys LiZn(X = As, P, and Sb) using a first principle approach based on Density Functional Theory (DFT). These alloys are of particular interest due to their potential applications in thermoelectric and spintronics devices. The corresponding Density of States (DOS) for the tripartite compounds LiZnX (X=As, P, and Sb) have been calculated and the contributions of the Li, Zn, As, P and Sb orbital to the Density of States at ambient pressure. This also confirmed that LiZnX (X=As, P, and Sb) is a semi-conductor with a narrow band-gap between the occupied and unoccupied regions around the Fermi level. The orbitals Li -1s, As-4p, As- 4s, Zn-3d has the highest contributions. The dominant of the orbitals P-1s and P-2p before the Fermi- level and Zn-2p after the Fermi-level are observed. We observed the dominant of the orbitals Sb-1s, Sb-3d, Li-1s, Li-2s, Zn-3d shows weak hybridization and low contribution. This features indicates that the covalent bond between these two atoms is weak, and could be responsible for the mechanical instability observed in the calculation. Meanwhile the band structure calculated and presented has narrow band-gab of 0.625. 0.937 and 0.313 respectively for the tripartite compound LiZnX(X=As, P, and Sb) and its a direct band-gap semiconductor. The obtained energy band structures provide valuable information about the electronic properties of LiZn (X = As, P, and Sb) alloys. The presence of band gaps is crucial for thermoelectric applications, as it indicates the presence of regions where electrons and holes are confined, enabling efficient charge transport.
{"title":"EVALUATION OF ENERGY BAND STRUCTURE OF HALF-HEUSLER ALLOY LiZnX (X = As, P, and Sb) USING FIRST PRINCIPLE CALCULATION","authors":"Emmanuel Ettah, Michael E. Ishaje, Kseniia Minakova, Esther Offiong Asuquo, Stephen U. Odey","doi":"10.20998/2413-4295.2023.03.02","DOIUrl":"https://doi.org/10.20998/2413-4295.2023.03.02","url":null,"abstract":"The evaluation of energy band structure plays a vital role in understanding the electronic properties of materials. This research, we investigate the energy band structure of Half-Heusler alloys LiZn(X = As, P, and Sb) using a first principle approach based on Density Functional Theory (DFT). These alloys are of particular interest due to their potential applications in thermoelectric and spintronics devices. The corresponding Density of States (DOS) for the tripartite compounds LiZnX (X=As, P, and Sb) have been calculated and the contributions of the Li, Zn, As, P and Sb orbital to the Density of States at ambient pressure. This also confirmed that LiZnX (X=As, P, and Sb) is a semi-conductor with a narrow band-gap between the occupied and unoccupied regions around the Fermi level. The orbitals Li -1s, As-4p, As- 4s, Zn-3d has the highest contributions. The dominant of the orbitals P-1s and P-2p before the Fermi- level and Zn-2p after the Fermi-level are observed. We observed the dominant of the orbitals Sb-1s, Sb-3d, Li-1s, Li-2s, Zn-3d shows weak hybridization and low contribution. This features indicates that the covalent bond between these two atoms is weak, and could be responsible for the mechanical instability observed in the calculation. Meanwhile the band structure calculated and presented has narrow band-gab of 0.625. 0.937 and 0.313 respectively for the tripartite compound LiZnX(X=As, P, and Sb) and its a direct band-gap semiconductor. The obtained energy band structures provide valuable information about the electronic properties of LiZn (X = As, P, and Sb) alloys. The presence of band gaps is crucial for thermoelectric applications, as it indicates the presence of regions where electrons and holes are confined, enabling efficient charge transport.","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135547849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.18698/0236-3941-2023-3-98-112
I.B. Stavitskiy, A.P. Naumov
The paper presents results of theoretical studies of the VT5 titanium alloy machinability by the electrodischarge machining method based on solving the thermal problem of the material phase transformation boundary displacement (Stefan problem). It proposes a method for determining parameters of electrical pulses for the VT5 alloy electrodischarge machining in order to increase the process productivity; recommendations are provided for that purpose. Density of the heat flux and its duration were determined necessary for implementation of the VT5 alloy electrodischarge machining process. Dependences were established of the minimum value of the heat flux pulse duration, when the VT5 alloy electrodischarge machining process was possible, and of maximum value of the heat flux pulse duration ensuring maximum removal of the VT5 alloy from the workpiece in one pulse, on the heat flux density. It is shown that for the maximum productivity of the VT5 alloy electrodischarge machining at the heat flux density used, it is necessary to assign effective duration of such a flux. Dependences of the heat flux effective duration on its density were established. Besides, to assign rational modes of VT5 ally electrodischarge machining, relationships were established and provided between the VT5 alloy machinability curves (dependences of the material penetration depth on the pulse duration) and other materials, including those for which rational modes are currently defined
{"title":"Optimizing Rational Modes in the Electrodischarge Machining of Parts Made of VT5 Titanium Alloy Based on Solving the Problem of Phase Material Conversion Boundary Displacement","authors":"I.B. Stavitskiy, A.P. Naumov","doi":"10.18698/0236-3941-2023-3-98-112","DOIUrl":"https://doi.org/10.18698/0236-3941-2023-3-98-112","url":null,"abstract":"The paper presents results of theoretical studies of the VT5 titanium alloy machinability by the electrodischarge machining method based on solving the thermal problem of the material phase transformation boundary displacement (Stefan problem). It proposes a method for determining parameters of electrical pulses for the VT5 alloy electrodischarge machining in order to increase the process productivity; recommendations are provided for that purpose. Density of the heat flux and its duration were determined necessary for implementation of the VT5 alloy electrodischarge machining process. Dependences were established of the minimum value of the heat flux pulse duration, when the VT5 alloy electrodischarge machining process was possible, and of maximum value of the heat flux pulse duration ensuring maximum removal of the VT5 alloy from the workpiece in one pulse, on the heat flux density. It is shown that for the maximum productivity of the VT5 alloy electrodischarge machining at the heat flux density used, it is necessary to assign effective duration of such a flux. Dependences of the heat flux effective duration on its density were established. Besides, to assign rational modes of VT5 ally electrodischarge machining, relationships were established and provided between the VT5 alloy machinability curves (dependences of the material penetration depth on the pulse duration) and other materials, including those for which rational modes are currently defined","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135639490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.18698/0236-3941-2023-3-113-126
T.I. Klebleev, V.Yu. Semenov
Currently, double-wall cryogenic non-isothermal tanks with vacuum-powder or vacuum-multilayer insulation are used in storage and transportation of such cryogenic liquids as liquid nitrogen, oxygen and liquefied natural gas. If the inner vessel is disrupted, the liquid spills into the heat-insulating space and evaporates as a result of heat inflow from the environment. This increases pressure in the thermal insulation space. To ensure functioning of the tank, it is necessary to limit pressure increase in the heat-insulating space. Results of experiments on evaporation of the liquid nitrogen entering the space filled with powder insulation were presented (expanded perlite was considered in the experiments). Experiments were carried out on a laboratory model simulating the tank heat-insulating space. Nature of the cryogenic liquid distribution in the powder insulation volume was determined, possibility of the cryogenic liquid direct contact with the walls of the tank was shown, and the tank walls temperatures and the cryogenic products evaporation intensity over time were determined. Based on the work results, physical and mathematical model of the emergency process development in the interwall space of a cryogenic tank associated with violation of the inner vessel tightness and subsequent spill of cryogenic liquid into the heat-insulating space was refined
{"title":"Experimental Study of Heat Transfer in the Interwall Space of a Cryogenic Tank with Powder Insulation","authors":"T.I. Klebleev, V.Yu. Semenov","doi":"10.18698/0236-3941-2023-3-113-126","DOIUrl":"https://doi.org/10.18698/0236-3941-2023-3-113-126","url":null,"abstract":"Currently, double-wall cryogenic non-isothermal tanks with vacuum-powder or vacuum-multilayer insulation are used in storage and transportation of such cryogenic liquids as liquid nitrogen, oxygen and liquefied natural gas. If the inner vessel is disrupted, the liquid spills into the heat-insulating space and evaporates as a result of heat inflow from the environment. This increases pressure in the thermal insulation space. To ensure functioning of the tank, it is necessary to limit pressure increase in the heat-insulating space. Results of experiments on evaporation of the liquid nitrogen entering the space filled with powder insulation were presented (expanded perlite was considered in the experiments). Experiments were carried out on a laboratory model simulating the tank heat-insulating space. Nature of the cryogenic liquid distribution in the powder insulation volume was determined, possibility of the cryogenic liquid direct contact with the walls of the tank was shown, and the tank walls temperatures and the cryogenic products evaporation intensity over time were determined. Based on the work results, physical and mathematical model of the emergency process development in the interwall space of a cryogenic tank associated with violation of the inner vessel tightness and subsequent spill of cryogenic liquid into the heat-insulating space was refined","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135639382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.18698/0236-3941-2023-3-127-139
A.V. Kostyukov, L.A. Kosach, V.G. Merzlikin
The paper presents analytical study of the distancing bulges effect on the thermal-hydraulic characteristics of a band slotted heat-transfer matrix of the rotary heat exchanger. The work was carried out based on mathematical simulation of the thermal-hydraulic processes in the band parallel-plate duct of low height (0.4 mm) at the laminar flow regime characteristic for the rotary heat exchangers. Influence of the distancing elements number in the rows, distance between the rows, as well as the total number of elements in the channel on the average value of the Nusselt number and on the magnitude of the pressure drop was analyzed. Influence of alterations in speed and temperature regimes on the thermal-hydraulic characteristics was analyzed. It was found that installation of the distancing bulges in a band parallel-plate duct led to a decrease in the Nusselt number and the increase in hydraulic resistance of the parallel-plate duct compared to a flat slotted duct without bulges despite the laminar flow regime. It was noted that influence of the distancing elements mutual arrangement on the bands was insignificant for the flow thermal-hydraulic characteristics. It was established that an increase in the temperature of the parallel-plate duct walls also was not leading to significant alteration in the heat transfer nature inside the channels under study; and alteration in the laminar flow speed regime also practically did not affect the heat transfer intensity in the ducts under consideration
{"title":"The Influence of Distancing Bulges in a Small-Width Parallel-Plate Duct on its Thermal-Hydraulic Characteristics at the Laminar Flow","authors":"A.V. Kostyukov, L.A. Kosach, V.G. Merzlikin","doi":"10.18698/0236-3941-2023-3-127-139","DOIUrl":"https://doi.org/10.18698/0236-3941-2023-3-127-139","url":null,"abstract":"The paper presents analytical study of the distancing bulges effect on the thermal-hydraulic characteristics of a band slotted heat-transfer matrix of the rotary heat exchanger. The work was carried out based on mathematical simulation of the thermal-hydraulic processes in the band parallel-plate duct of low height (0.4 mm) at the laminar flow regime characteristic for the rotary heat exchangers. Influence of the distancing elements number in the rows, distance between the rows, as well as the total number of elements in the channel on the average value of the Nusselt number and on the magnitude of the pressure drop was analyzed. Influence of alterations in speed and temperature regimes on the thermal-hydraulic characteristics was analyzed. It was found that installation of the distancing bulges in a band parallel-plate duct led to a decrease in the Nusselt number and the increase in hydraulic resistance of the parallel-plate duct compared to a flat slotted duct without bulges despite the laminar flow regime. It was noted that influence of the distancing elements mutual arrangement on the bands was insignificant for the flow thermal-hydraulic characteristics. It was established that an increase in the temperature of the parallel-plate duct walls also was not leading to significant alteration in the heat transfer nature inside the channels under study; and alteration in the laminar flow speed regime also practically did not affect the heat transfer intensity in the ducts under consideration","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135638920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.18698/0236-3941-2023-3-64-88
S.A. Vasin, E.V. Pantyukhina
Modern equipment in the product assembly should be the automatically loaded reliable systems, where the hopper loading-orientation device is the main component. Recently, there appeared a lot of asymmetric parts, including those with implicit asymmetry. In this connection, it becomes necessary to design such capture devices that are optimal in all the parameters. However, the probabilistic operation principle and the device ability to operate only in capturing a specific part with certain geometric parameters significantly complicate their design and require solution to the complex multi-level tasks. The most important task is to determine its performance, namely the probability of capturing the parts in the hopper loading-orientation device. The paper presents a detailed methodology making it possible to determine the probability of capturing the parts in the bunker loading-orientation devices of various types that implement different methods in capturing and orienting parts with the revolution body shape of a wide range, both with implicit and explicit asymmetry, for constructing the performance mathematical model. To build a mathematical model of the capture probability, probabilities of finding the part in the favorable position for capturing it with its differing orientations, limiting circumferential speed of the capturing bodies of the hopper loading-orientation device and absence of interference from the interlocking parts were determined. Dependencies are provided that are making it possible to graphically determine the indicated parameters of the mathematical model
{"title":"Method for Determining Probability of Capturing the Asymmetric Parts with the Rotation Body Shape in the Disk Hopper Loading-Orientation Devices","authors":"S.A. Vasin, E.V. Pantyukhina","doi":"10.18698/0236-3941-2023-3-64-88","DOIUrl":"https://doi.org/10.18698/0236-3941-2023-3-64-88","url":null,"abstract":"Modern equipment in the product assembly should be the automatically loaded reliable systems, where the hopper loading-orientation device is the main component. Recently, there appeared a lot of asymmetric parts, including those with implicit asymmetry. In this connection, it becomes necessary to design such capture devices that are optimal in all the parameters. However, the probabilistic operation principle and the device ability to operate only in capturing a specific part with certain geometric parameters significantly complicate their design and require solution to the complex multi-level tasks. The most important task is to determine its performance, namely the probability of capturing the parts in the hopper loading-orientation device. The paper presents a detailed methodology making it possible to determine the probability of capturing the parts in the bunker loading-orientation devices of various types that implement different methods in capturing and orienting parts with the revolution body shape of a wide range, both with implicit and explicit asymmetry, for constructing the performance mathematical model. To build a mathematical model of the capture probability, probabilities of finding the part in the favorable position for capturing it with its differing orientations, limiting circumferential speed of the capturing bodies of the hopper loading-orientation device and absence of interference from the interlocking parts were determined. Dependencies are provided that are making it possible to graphically determine the indicated parameters of the mathematical model","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135639379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.18698/0236-3941-2023-3-29-49
A.E. Belkin, E.A. Nikitin
The paper considers the shock absorption system of an advanced domestic mainline passenger aircraft, which includes oleo-pneumatic shock absorbers and wheels equipped with the pneumatic tires. Nonlinear mathematical models of single-active and two-active oleo-pneumatic shock absorbers of telescopic landing gear supports are proposed. The models take into account the process of polytropic gas compression, the forces of hydraulic resistance to the working fluid flow and the forces of dry friction arising in the system moving parts. To describe the vertical compression reaction of the pneumatic tires, the V.L. Biderman structural model was introduced, which parameters were determined by test results using the least squares method. Motion equations of the landing gear elements were obtained by the analytical mechanics methods involving the Ostrogradsky --- Hamilton variational principle of least action. Constraints imposed on the system were introduced using the penalty functions method. The problem statement of carrying out virtual computational experiments on the landing gear dvops was considered. In a wide range of the impact energies, models of shock absorbers of a passenger aircraft landing gear were validated, for which time realizations of the system state vector were determined, and areas of hysteresis loops of the shock absorber load characteristics were evaluated by the numerical integration. Satisfactory compliance of the results of simulated characteristics of the natural objects was shown. The obtained results could be used to improve the absorption quality criteria by numerical optimization methods, calculate the landing impacts and analyze the aircraft oscillations when moving on the runway
{"title":"Calculation of the Passenger Aircraft Landing Gear Shock Absorption System Exposed to Impact Loading","authors":"A.E. Belkin, E.A. Nikitin","doi":"10.18698/0236-3941-2023-3-29-49","DOIUrl":"https://doi.org/10.18698/0236-3941-2023-3-29-49","url":null,"abstract":"The paper considers the shock absorption system of an advanced domestic mainline passenger aircraft, which includes oleo-pneumatic shock absorbers and wheels equipped with the pneumatic tires. Nonlinear mathematical models of single-active and two-active oleo-pneumatic shock absorbers of telescopic landing gear supports are proposed. The models take into account the process of polytropic gas compression, the forces of hydraulic resistance to the working fluid flow and the forces of dry friction arising in the system moving parts. To describe the vertical compression reaction of the pneumatic tires, the V.L. Biderman structural model was introduced, which parameters were determined by test results using the least squares method. Motion equations of the landing gear elements were obtained by the analytical mechanics methods involving the Ostrogradsky --- Hamilton variational principle of least action. Constraints imposed on the system were introduced using the penalty functions method. The problem statement of carrying out virtual computational experiments on the landing gear dvops was considered. In a wide range of the impact energies, models of shock absorbers of a passenger aircraft landing gear were validated, for which time realizations of the system state vector were determined, and areas of hysteresis loops of the shock absorber load characteristics were evaluated by the numerical integration. Satisfactory compliance of the results of simulated characteristics of the natural objects was shown. The obtained results could be used to improve the absorption quality criteria by numerical optimization methods, calculate the landing impacts and analyze the aircraft oscillations when moving on the runway","PeriodicalId":32537,"journal":{"name":"Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135639391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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