Pub Date : 2023-04-28DOI: 10.24840/2183-6493_009-003_001844
Johanna Johnsson, Therese Tufvesson, Jose M. Costa
Additive Manufacturing (AM) unlocked a new way of producing advanced structures that are stronger and use less material, enabling new possibilities due to design freedom, easiness of manufacturing complex parts, and mass personalization. One of the most common AM processes is Fused Filament Fabrication (FFF), which is mainly used to manufacture polymer parts. However, FFF can also produce metallic components, which is not as simple and direct since it requires debinding and sintering processes. This study was conducted to develop the knowledge of FFF using metal and aims to evaluate the characteristics of D2 tool steel. The mechanical and microstructural properties were evaluated, and the results were compared with the supplier's datasheets.
{"title":"Characterization of D2 Tool Steel fabricated thru Fused Filament Fabrication Process","authors":"Johanna Johnsson, Therese Tufvesson, Jose M. Costa","doi":"10.24840/2183-6493_009-003_001844","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001844","url":null,"abstract":"Additive Manufacturing (AM) unlocked a new way of producing advanced structures that are stronger and use less material, enabling new possibilities due to design freedom, easiness of manufacturing complex parts, and mass personalization. One of the most common AM processes is Fused Filament Fabrication (FFF), which is mainly used to manufacture polymer parts. However, FFF can also produce metallic components, which is not as simple and direct since it requires debinding and sintering processes. This study was conducted to develop the knowledge of FFF using metal and aims to evaluate the characteristics of D2 tool steel. The mechanical and microstructural properties were evaluated, and the results were compared with the supplier's datasheets.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84285039","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001898
D. Persano Adorno, Tuba Uğraş, J. S. Quaicoe, Veselina G. Jecheva, A. Ogunyemi, M. Bauters, A. Toshkov, Y. Ortakci, Kasim Ozacar, Ferhat Atasoy, D. Peri, S. Kocijancic, David Rihtaršič, Špela Cerar, Hüseyin Uvet
Industry 4.0 and 5.0 topics are emerging fields and have seen rising demand recently. There is a critical need, on the other hand, for improved methods of instructing programming languages since a growing lack of student motivation during the pandemic has had a deleterious influence on the education of programmers. In this context, online/hybrid computer programming courses must be addressed with innovative solutions to support the field with well-educated professionals. In this paper, we present a case study to propose an innovative tailored instructional design for the online/hybrid learning environments for programming courses in engineering faculties. To develop the instructional design, the Kemp Instructional Design Model was followed. The instructional design is a result of the main outputs of the RECOM “Redesigning Introductory Computer Programming Using Innovative Online Modules” project, which aims to bridge the gap between the existing course design in programming courses and the needs of "Covid” and “post-Covid” generation students.
{"title":"An innovative tailored instructional design for computer programming courses in engineering","authors":"D. Persano Adorno, Tuba Uğraş, J. S. Quaicoe, Veselina G. Jecheva, A. Ogunyemi, M. Bauters, A. Toshkov, Y. Ortakci, Kasim Ozacar, Ferhat Atasoy, D. Peri, S. Kocijancic, David Rihtaršič, Špela Cerar, Hüseyin Uvet","doi":"10.24840/2183-6493_009-003_001898","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001898","url":null,"abstract":"Industry 4.0 and 5.0 topics are emerging fields and have seen rising demand recently. There is a critical need, on the other hand, for improved methods of instructing programming languages since a growing lack of student motivation during the pandemic has had a deleterious influence on the education of programmers. In this context, online/hybrid computer programming courses must be addressed with innovative solutions to support the field with well-educated professionals. In this paper, we present a case study to propose an innovative tailored instructional design for the online/hybrid learning environments for programming courses in engineering faculties. To develop the instructional design, the Kemp Instructional Design Model was followed. The instructional design is a result of the main outputs of the RECOM “Redesigning Introductory Computer Programming Using Innovative Online Modules” project, which aims to bridge the gap between the existing course design in programming courses and the needs of \"Covid” and “post-Covid” generation students.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86940389","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001939
Analcísio António Rodino, R. Araújo
Due to the advancement of power electronics devices and control techniques, the modular multilevel converter (MMC) has become the most attractive converter for multiterminal direct current (MTDC) grids thanks to its most relevant features, such as modularity and scalability. Despite their advantages, conventional MMCs face a major challenge with: i) fault-tolerant operation strategy; i) energy losses in conversion; iii) lack of DC fault handling capability. This paper provides a systematic review to identify the gaps in the literature about Intelligent Fault-Tolerant Protection Schemes for multi-terminal HVDC grids. Through the bibliometric analysis, it was possible to identify topics still to be developed within the four main clusters (Offshore wind farms, Wind turbines, Voltage Source Converters, and Wind power). The research topic opens three research paths: the first is the analysis of failures in HVDC (High Voltage Direct Current) grid equipment by the FDD (Fault Detection and Diagnosis) method; the second is failure analysis by the IFDD (Inverse Fault Detection and Diagnosis) method and the third is the possibility of interconnecting the different energy generation zones with different frequencies.
{"title":"A systematic review of Intelligent Fault-Tolerant Protection Scheme for Multi-terminal HVDC Grids","authors":"Analcísio António Rodino, R. Araújo","doi":"10.24840/2183-6493_009-003_001939","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001939","url":null,"abstract":"\u0000 \u0000 \u0000Due to the advancement of power electronics devices and control techniques, the modular multilevel converter (MMC) has become the most attractive converter for multiterminal direct current (MTDC) grids thanks to its most relevant features, such as modularity and scalability. Despite their advantages, conventional MMCs face a major challenge with: i) fault-tolerant operation strategy; i) energy losses in conversion; iii) lack of DC fault handling capability. This paper provides a systematic review to identify the gaps in the literature about Intelligent Fault-Tolerant Protection Schemes for multi-terminal HVDC grids. Through the bibliometric analysis, it was possible to identify topics still to be developed within the four main clusters (Offshore wind farms, Wind turbines, Voltage Source Converters, and Wind power). The research topic opens three research paths: the first is the analysis of failures in HVDC (High Voltage Direct Current) grid equipment by the FDD (Fault Detection and Diagnosis) method; the second is failure analysis by the IFDD (Inverse Fault Detection and Diagnosis) method and the third is the possibility of interconnecting the different energy generation zones with different frequencies. \u0000 \u0000 \u0000","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75762953","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001132
Gagandeep Singh, A. Jayant
The recent rise in the demand for high precision, close tolerances, and super surface finish quality of components and part assembly modules in the competitive manufacturing industrial environment for the enhanced working life and functional requirements of machines globally. Three revolving curved tip tools based magnetorheological process is designed and developed to fine finish the external cylindrical surfaces of soft and hard materials. The effect of the key operational machining parameters on the surface roughness of a newly developed magnetorheological process was carried out using a one factor at a time method. The magnetizing current, the revolving speed of the tools, the rotational speed of the workpiece, workpiece traverse speed are the parameters that have been considered for this purpose. The experimentation has been performed on the aluminium workpiece because of its broad applicability, such as manufacturing shafts, rods, pistons, and other circular components. The primary purpose of this study was to determine the range of essential control parameters for the newly developed finishing process. The percentage reduction in Ra, Rq, and Rz values are 69.64%, 58.21%, and 54.48%, respectively, after 60 minutes of finishing at magnetizing current 2A, the revolving speed of the tools 30 RPM, the rotation speed of the workpiece 600 RPM and feed 10 cm/min.
{"title":"Investigation of Process Parameters of a Novel Magnetorheological Finishing Process for External Cylindrical Surfaces","authors":"Gagandeep Singh, A. Jayant","doi":"10.24840/2183-6493_009-003_001132","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001132","url":null,"abstract":"The recent rise in the demand for high precision, close tolerances, and super surface finish quality of components and part assembly modules in the competitive manufacturing industrial environment for the enhanced working life and functional requirements of machines globally. Three revolving curved tip tools based magnetorheological process is designed and developed to fine finish the external cylindrical surfaces of soft and hard materials. The effect of the key operational machining parameters on the surface roughness of a newly developed magnetorheological process was carried out using a one factor at a time method. The magnetizing current, the revolving speed of the tools, the rotational speed of the workpiece, workpiece traverse speed are the parameters that have been considered for this purpose. The experimentation has been performed on the aluminium workpiece because of its broad applicability, such as manufacturing shafts, rods, pistons, and other circular components. The primary purpose of this study was to determine the range of essential control parameters for the newly developed finishing process. The percentage reduction in Ra, Rq, and Rz values are 69.64%, 58.21%, and 54.48%, respectively, after 60 minutes of finishing at magnetizing current 2A, the revolving speed of the tools 30 RPM, the rotation speed of the workpiece 600 RPM and feed 10 cm/min.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81638819","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001880
L. Solazzi, Alberto Mazzoni, M. Cima
Reliability and efficiency of automotive and industrial vehicles are strongly affected by the behaviour of the components involved in the interaction with the ground. For this reason, components like tyres, wheels and suspension systems are physically tested, for performance and durability assessment. Anyway, standard test machines are generally designed for testing only one specific component.The aim of this work is the design of an innovative test machine, able to perform different kinds of tests, for tyre, wheel and suspension system components, on a unique bench. The machine is a flat track type, better fit than traditional drum types in simulating real tyre-to-ground contact conditions. The core of the machine is a Gough-Stewart platform, where the flat track is fixed, which is moved by six hydraulic actuators to reproduce multiple work configurations, for extended time periods or numerous test block repetitions. After the preliminary design phase, the machine components were subjected to topology optimization and modal analysis by FEM, to reduce weights and avoid any issues related to the expected working frequencies. Given the quality of the results achieved, currently, the software design for closed-loop control configuration is under development, for the machine prototype next construction.
{"title":"Development of an innovative test machine for tyre, wheel and suspension systems for automotive and industrial vehicles","authors":"L. Solazzi, Alberto Mazzoni, M. Cima","doi":"10.24840/2183-6493_009-003_001880","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001880","url":null,"abstract":"Reliability and efficiency of automotive and industrial vehicles are strongly affected by the behaviour of the components involved in the interaction with the ground. For this reason, components like tyres, wheels and suspension systems are physically tested, for performance and durability assessment. Anyway, standard test machines are generally designed for testing only one specific component.The aim of this work is the design of an innovative test machine, able to perform different kinds of tests, for tyre, wheel and suspension system components, on a unique bench. The machine is a flat track type, better fit than traditional drum types in simulating real tyre-to-ground contact conditions. The core of the machine is a Gough-Stewart platform, where the flat track is fixed, which is moved by six hydraulic actuators to reproduce multiple work configurations, for extended time periods or numerous test block repetitions. After the preliminary design phase, the machine components were subjected to topology optimization and modal analysis by FEM, to reduce weights and avoid any issues related to the expected working frequencies. Given the quality of the results achieved, currently, the software design for closed-loop control configuration is under development, for the machine prototype next construction.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85961309","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001749
Sonu Ram Sonu Ram, RAJ KUMAR YADAV, INDRAJ SINGH
This research aims to compare the potential and existing conditions of a small-sized spark ignition (SI) engine with a 1.0-liter capacity suitable for cylinder deactivation. The cylinder deactivation strategy is used to solve the issues of inefficient combustion and increased exhaust emission under part loading. Consequently, the possibility of implementing cylinder deactivation in terms of decreased exhaust pollution has been assessed. A computerized, 1.0-liter, 4-stroke, water-cooled, spark-ignition engine with an open engine control unit (ECU) and multi-point fuel injection (MPFI) was used for the trials. Both modes were tested at 2500 revolutions per minute (RPM) under loads of 15, 30, and 45 N-m. The spark plug and fuel injector deactivate the cylinder. The results show that when the highest possible load is used, the peak cylinder pressure is 55.78% higher, and the maximum heat release rate is 53.96% more in the deactivation mode than in the traditional mode. In deactivation mode, the mass fraction consumed is larger at each crank angle point, suggesting a faster rate of combustion and increased combustion efficiency. The increased mean gas temperature permits the catalytic converter to perform more efficiently after downsizing. When compared to the conventional mode, carbon monoxide (CO) emission is almost non-existent at full load, unburned hydrocarbon (UHC) is reduced by 92.89%, and oxides of nitrogen (NOx) are reduced by 35% in the deactivation mode. Furthermore, the experiment indicated that, when employed at part load, the deactivation mode is more beneficial than the standard mode in terms of better combustion stability and lesser emissions.
{"title":"Combustion and Exhaust Emission Improvement in a 3-Cylinder Mpfi Engine Through Downsizing","authors":"Sonu Ram Sonu Ram, RAJ KUMAR YADAV, INDRAJ SINGH","doi":"10.24840/2183-6493_009-003_001749","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001749","url":null,"abstract":"This research aims to compare the potential and existing conditions of a small-sized spark ignition (SI) engine with a 1.0-liter capacity suitable for cylinder deactivation. The cylinder deactivation strategy is used to solve the issues of inefficient combustion and increased exhaust emission under part loading. Consequently, the possibility of implementing cylinder deactivation in terms of decreased exhaust pollution has been assessed. A computerized, 1.0-liter, 4-stroke, water-cooled, spark-ignition engine with an open engine control unit (ECU) and multi-point fuel injection (MPFI) was used for the trials. Both modes were tested at 2500 revolutions per minute (RPM) under loads of 15, 30, and 45 N-m. The spark plug and fuel injector deactivate the cylinder. The results show that when the highest possible load is used, the peak cylinder pressure is 55.78% higher, and the maximum heat release rate is 53.96% more in the deactivation mode than in the traditional mode. In deactivation mode, the mass fraction consumed is larger at each crank angle point, suggesting a faster rate of combustion and increased combustion efficiency. The increased mean gas temperature permits the catalytic converter to perform more efficiently after downsizing. When compared to the conventional mode, carbon monoxide (CO) emission is almost non-existent at full load, unburned hydrocarbon (UHC) is reduced by 92.89%, and oxides of nitrogen (NOx) are reduced by 35% in the deactivation mode. Furthermore, the experiment indicated that, when employed at part load, the deactivation mode is more beneficial than the standard mode in terms of better combustion stability and lesser emissions.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83553120","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001790
B. V, Chandra Shekhar Reddy Atla, M. Shivakumar
Power systems need reactive power support to withstand voltage instability issues. The Volt Ampere reactive (VAr) resources are to be optimally determined for location and size. Generally, candidate locations are determined based on the ranking of buses according to sensitivity indices, and the Trajectory Sensitivity Index (TSI) is the most widely used sensitivity index. However, the locations identified by ranking the buses at the system level using the TSI method do not guarantee an optimal VAr solution. The recent methods based on dividing the power system into zones address the issue of optimality. The prevailing zoning methods are based on the computation of the electrical distance between buses and do not address the zoning scenario where the electrical distance between the buses is indeterminable. This paper introduces a new multistage algorithm for grouping the buses into zones even when the electrical distance is indeterminable. The new proposed strategy encompasses applying proposed analytical and parametric techniques after the standard clustering steps. A new index, namely the Bilateral Sensitivity Index (BSI), is introduced to quantify the proximity of buses. The TSI-based zonal level ranking of buses is introduced. The proposed strategy demonstrates that when TSI is employed to rank the buses at the zonal level rather than at the system level, it helps towards an optimal VAr solution. The new multistage clustering strategy is integrated into the generalized Dynamic Voltage Stability Analysis (DVSA) framework for optimal VAr determination and applied to study the voltage collapse phenomenon on a practical 24-bus system in the southern part of India. The results demonstrate the proposed approach’s efficacy in mitigating voltage instability issues through optimal VAr support.
{"title":"A New Multistage Clustering Algorithm for Optimal VAr Planning For Dynamic Voltage Stability Analysis","authors":"B. V, Chandra Shekhar Reddy Atla, M. Shivakumar","doi":"10.24840/2183-6493_009-003_001790","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001790","url":null,"abstract":"Power systems need reactive power support to withstand voltage instability issues. The Volt Ampere reactive (VAr) resources are to be optimally determined for location and size. Generally, candidate locations are determined based on the ranking of buses according to sensitivity indices, and the Trajectory Sensitivity Index (TSI) is the most widely used sensitivity index. However, the locations identified by ranking the buses at the system level using the TSI method do not guarantee an optimal VAr solution. The recent methods based on dividing the power system into zones address the issue of optimality. The prevailing zoning methods are based on the computation of the electrical distance between buses and do not address the zoning scenario where the electrical distance between the buses is indeterminable. This paper introduces a new multistage algorithm for grouping the buses into zones even when the electrical distance is indeterminable. The new proposed strategy encompasses applying proposed analytical and parametric techniques after the standard clustering steps. A new index, namely the Bilateral Sensitivity Index (BSI), is introduced to quantify the proximity of buses. The TSI-based zonal level ranking of buses is introduced. The proposed strategy demonstrates that when TSI is employed to rank the buses at the zonal level rather than at the system level, it helps towards an optimal VAr solution. The new multistage clustering strategy is integrated into the generalized Dynamic Voltage Stability Analysis (DVSA) framework for optimal VAr determination and applied to study the voltage collapse phenomenon on a practical 24-bus system in the southern part of India. The results demonstrate the proposed approach’s efficacy in mitigating voltage instability issues through optimal VAr support.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86414706","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001600
Jayesh U. Kothavade, P. Kundu
In High Voltage Direct Current Transmission (HVDC) system, converter transformer (CT) is an essential part of the system. Losses that occur in the CT are copper loss, stray loss, and core loss. The stray loss occurs in the transformer's metallic parts, such as transformer tank, which is 10% to 15% of the total loss. Current flowing through the CT is non-sinusoidal current, so more losses are produced in the CT than normal power transformer. In this paper, horizontal wall shunt is used to reduce stray loss in CT and compare the performance with vertical wall shunt. These stray losses calculated using the 3-D finite –element analysis (FEA). A 315 MVA CT is considered as a case study to calculate stray losses with and without wall shunt. Results show that the horizontal wall shunt is effective compared to vertical wall shunt; additionally, the stray loss is reduced as the wall shunt thickness is increased. Therefore, the efficiency of CT is increased due to a decrease in stray loss.
{"title":"Improvement in Efficiency of Converter Transformer by The Reduction of Stray Losses","authors":"Jayesh U. Kothavade, P. Kundu","doi":"10.24840/2183-6493_009-003_001600","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001600","url":null,"abstract":"In High Voltage Direct Current Transmission (HVDC) system, converter transformer (CT) is an essential part of the system. Losses that occur in the CT are copper loss, stray loss, and core loss. The stray loss occurs in the transformer's metallic parts, such as transformer tank, which is 10% to 15% of the total loss. Current flowing through the CT is non-sinusoidal current, so more losses are produced in the CT than normal power transformer. In this paper, horizontal wall shunt is used to reduce stray loss in CT and compare the performance with vertical wall shunt. These stray losses calculated using the 3-D finite –element analysis (FEA). A 315 MVA CT is considered as a case study to calculate stray losses with and without wall shunt. Results show that the horizontal wall shunt is effective compared to vertical wall shunt; additionally, the stray loss is reduced as the wall shunt thickness is increased. Therefore, the efficiency of CT is increased due to a decrease in stray loss.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76671461","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 : 2023-04-28DOI: 10.24840/2183-6493_009-002_001508
Jithender Jatoth, A. Mehar
The signalized intersections are essential nodes that directly affect the performance of the whole roadway network. The heterogeneous traffic at approaches signalized intersection makes traffic flow more chaotic. Evaluating the performance of signalized intersections is essential by taking queue length, PCU, delay, and capacity for improving the overall service quality. The guidelines followed in developed countries are not directly applicable in a country like India for practical evaluation of traffic operations. Therefore, it is necessary to analyze performance of intersections by making use of queued vehicles to develop PCU and delay models at signalized intersections in mixed traffic conditions. The present study analyzed queue length and developed a model to estimate PCU values, capacity, and delay by collecting field data from the approaches of signalized intersections in Warangal City using video graphic technic. The statistical distribution was carried out to show the significance of observed queue length, acceleration, and deceleration obtained from the field. Furthermore, new models proposed in the present study were also validated using field data, which confirms the successful validation of the models under mixed traffic conditions. The study recommends evaluating the level of service based on queue length and the proposed delay model at approaches of signalized intersections.
{"title":"Modeling Passenger Car Unit and Delay at Signalized Intersections in Mixed Traffic Conditions","authors":"Jithender Jatoth, A. Mehar","doi":"10.24840/2183-6493_009-002_001508","DOIUrl":"https://doi.org/10.24840/2183-6493_009-002_001508","url":null,"abstract":"The signalized intersections are essential nodes that directly affect the performance of the whole roadway network. The heterogeneous traffic at approaches signalized intersection makes traffic flow more chaotic. Evaluating the performance of signalized intersections is essential by taking queue length, PCU, delay, and capacity for improving the overall service quality. The guidelines followed in developed countries are not directly applicable in a country like India for practical evaluation of traffic operations. Therefore, it is necessary to analyze performance of intersections by making use of queued vehicles to develop PCU and delay models at signalized intersections in mixed traffic conditions. The present study analyzed queue length and developed a model to estimate PCU values, capacity, and delay by collecting field data from the approaches of signalized intersections in Warangal City using video graphic technic. The statistical distribution was carried out to show the significance of observed queue length, acceleration, and deceleration obtained from the field. Furthermore, new models proposed in the present study were also validated using field data, which confirms the successful validation of the models under mixed traffic conditions. The study recommends evaluating the level of service based on queue length and the proposed delay model at approaches of signalized intersections.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81856913","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 : 2023-04-28DOI: 10.24840/2183-6493_009-003_001968
Sérgio Ricardo Toledo Salgado, Elsa Maria da Silva Carvalho
The Brazilian National Policy on Dam Safety (PNSB) was enacted in 2010 and there are still many actions to be carried out, especially the classification of dams as to associated hazard potential (PHA) and risk category (RC). The analysis conducted based on the Dam Safety Report 2020 informs that there are 21953 dams distributed throughout the Brazilian territory registered in National Dam Information System (SNISB). However, 14849 (67.64%) of the dams were not classified as RC and 13475 (61.38%) of the dams were not classified as PHA. There are 3724 dams classified as high PHA, 2407 (64.64%) of which are considered small in terms of reservoir capacity. Considering this scenario, bibliographic research was conducted on dam classification criteria used in Brazil, Portugal, International Commission on Large (ICOLD) and United States. In addition, bibliographic research was conducted on two studies that used artificial intelligence-based tools to forecast PHA classification. As a result, this study recommends future research with indicated classification criteria and with applications based on artificial intelligence to forecast PHA classification in Brazil.
{"title":"Recommendations for the process of classification of dams in Brazil","authors":"Sérgio Ricardo Toledo Salgado, Elsa Maria da Silva Carvalho","doi":"10.24840/2183-6493_009-003_001968","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001968","url":null,"abstract":"The Brazilian National Policy on Dam Safety (PNSB) was enacted in 2010 and there are still many actions to be carried out, especially the classification of dams as to associated hazard potential (PHA) and risk category (RC). The analysis conducted based on the Dam Safety Report 2020 informs that there are 21953 dams distributed throughout the Brazilian territory registered in National Dam Information System (SNISB). However, 14849 (67.64%) of the dams were not classified as RC and 13475 (61.38%) of the dams were not classified as PHA. There are 3724 dams classified as high PHA, 2407 (64.64%) of which are considered small in terms of reservoir capacity. Considering this scenario, bibliographic research was conducted on dam classification criteria used in Brazil, Portugal, International Commission on Large (ICOLD) and United States. In addition, bibliographic research was conducted on two studies that used artificial intelligence-based tools to forecast PHA classification. As a result, this study recommends future research with indicated classification criteria and with applications based on artificial intelligence to forecast PHA classification in Brazil.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85123431","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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