Vestnik Dagestanskogo Gosudarstvennogo Tehniceskogo Universiteta Tehniceskie Nauki最新文献

{"title":"Modeling of the flow and heat exchange in pipes with turbulators of viscous heat carriers in the laminar region, as well as in the transition to turbulent flow","authors":"I. E. Lobanov","doi":"10.21822/2073-6185-2023-50-3-24-36","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-3-24-36","url":null,"abstract":"Objective . Mathematical modeling of heat transfer in pipes with turbulators for viscous heat carriers at Reynolds numbers characteristic of laminar and transient flow regimes is carried out by the calculation method. The solution of the heat exchange problem for semicircular cross-section flow turbulators based on multiblock computing technologies based on the solution of the Reynolds equations (closed for the transient mode using the Menter shear stress transfer model) and the energy equation (on multi-scale intersecting structured grids) by the factorized finite-volume method (FCOM) was considered. Method . The calculation was carried out on the basis of a theoretical method based on the solution of the Reynolds equations, closed for transient modes using the Menter shear stress transfer model, and the energy equation on multiscale intersecting structured grids (FCOM), by a factorized finite-volume method. Result . Both local and averaged characteristics of the flow and heat exchange in pipes with turbulators for a viscous coolant for laminar and transient flow modes of the coolant were obtained using the FCOM method in the work, which made it possible to determine for these modes the levels of heat exchange intensification that satisfactorily correlate with the existing experiment. Conclusion . The calculated relative hydraulic resistance for low turbulators increases quite slightly, and for medium-altitude turbulators reaches 2÷2.5 to the critical Reynolds number, and subsequently it increases up to 3 times; for high turbulators, the relative hydraulic resistance increases up to 4 times even before the transition flow regime is reached, after which it increases up to 4.5 times. The calculated relative isothermal intensified heat exchange under the laminar flow regime of a viscous coolant for relatively high turbulators increases almost 2 times; for relatively medium heights of turbulators — almost one and a half, and for low relative heights, the intensification of heat exchange is insignificant.","PeriodicalId":31714,"journal":{"name":"Vestnik Dagestanskogo Gosudarstvennogo Tehniceskogo Universiteta Tehniceskie Nauki","volume":"233 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136312643","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}

{"title":"Recommendations for using a methodology for assessing the security of an automated control system for critical information infrastructure from DDoS attacks based on Monte Carlo simulation","authors":"V. A. Voevodin, V. S. Chernyaev, I. V. Vinogradov","doi":"10.21822/2073-6185-2023-50-3-57-65","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-3-57-65","url":null,"abstract":"Objective . The objective of the research is to develop a methodology for the security of an automated control system of critical information infrastructure from DDoS attacks. The methodology allows the decision-maker to obtain an assessment of the risk of exposure of the computer network (CN) to DDoS attacks and take necessary actions to reduce the risk of this threat. Method . To achieve the stated objective of the research, simulation modeling based on the Monte Carlo method was used, implemented within the framework of a specialized software environment, as well as a method for calculating integral risk. Result . A methodology was proposed for assessing the security of an automated control system for critical information infrastructure from DDoS attacks, taking into account the importance of individual nodes of its CN. Conclusion . Thus, the developed methodology is useful when conducting an information security audit to assess the integral risk of impact implementation of a DDoS attack on a CN and is designed to help an organization achieve global information security goals, as well as to justify the amount of the insurance premium paid when insuring cyber risks.","PeriodicalId":31714,"journal":{"name":"Vestnik Dagestanskogo Gosudarstvennogo Tehniceskogo Universiteta Tehniceskie Nauki","volume":"4 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136312503","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}

{"title":"Modeling of a low-temperature gas treatment system","authors":"M. P. Kuznetsov","doi":"10.21822/2073-6185-2023-50-3-14-23","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-3-14-23","url":null,"abstract":"Objective . The main purpose of the work is: investigation of the effect of changes in technological parameters on the efficiency of the separation process and determination of optimal technological modes of operation of gas field X CNTS in the separation process. Method . The problem was solved in the KBC Petro-SIM computer program and the LTS model was built. To conduct the study, a model of the LTS was built in the KBC Petro-SIM computer program. Result . The results obtained with the help of it showed: with the current composition of the gas with a decrease in temperature for every 2 o C, with other technological indicators being equal, the specific condensate yield increases in the range from 15 to 30%, and the lower the temperature, the higher this percentage. When the pressure on the throttle decreases by every 0.4 MPa, the condensate output increases, if the pressure drops below 1.8 MPa, the specific condensate output will begin to decrease, which is explained by the pressure drop below the maximum condensation line of the phase diagram. The change in gas flow within the design values did not affect the operation of low-temperature separation. At any available low temperature and high pressure at the inlet to the ILTS, the most optimal mode will be when the pressure after the throttle is maintained within 1.8 - 1.9 MPa. The maximum specific yield of gas condensate (48.21%) was obtained at a pressure at the inlet to the ILTS of 5.1 MPa, a temperature after the heat exchanger of minus 2 o C and a pressure drop at the throttle of 3.05 MPa. As part of the numerical research, the following results were obtained: with an increase in the pressure at the inlet to the ILTC, the change in the specific output of the gas condensate is insignificant, but with this parameter it is possible to create a larger pressure drop on the throttle; with a decrease in the gas temperature at the outlet of the heat exchanger, the specific yield of the gas condensate will increase; with an increase in the pressure drop at the throttle, the specific output of the gas condensate increases until the pressure after the throttle reaches the range of values of 1.8 – 1.9 MPa. In this interval, the maximum specific condensate yield is achieved. With a further increase in the pressure drop on the throttle, the specific output of the gas condensate decreases. This is explained by the phenomenon of retrograde condensation, since the maximum condensation line is in the range of these pressures. Conclusion . Based on the results of the work, it was found that the developed software module can be used to solve the emerging series of problems. The results of the work show the suitability of the proposed method for practical purposes.","PeriodicalId":31714,"journal":{"name":"Vestnik Dagestanskogo Gosudarstvennogo Tehniceskogo Universiteta Tehniceskie Nauki","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136312642","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}

{"title":"Formatting requirements for papers","authors":"Artiсle Editorial","doi":"10.21822/2073-6185-2023-50-1-245-247","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-245-247","url":null,"abstract":".","PeriodicalId":31714,"journal":{"name":"Vestnik Dagestanskogo Gosudarstvennogo Tehniceskogo Universiteta Tehniceskie Nauki","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135337023","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}