Pub Date : 2020-05-15DOI: 10.5545/sv-jme.2020.6557
B. Bizjan, B. Širok, M. Blagojevič
In this paper, the process of mineral fiber formation was investigated experimentally on a two-wheel spinner by means of high-speed imaging. Analogue isomalt melt was fiberized at different rotational speeds of spinner wheels, melt flow rates and impingement positions so that the fiberization process was dynamically similar to an industrial mineral wool production process. Images of fiber formation and transport reveal highly complex dynamics of these processes, as fibers mostly occur in form of 3D mutually intertwined structures such as clusters, strands and veils periodically shedding from the melt film. Despite the complexity of flow structures, there is a clear trend of increasing mean fiber length and expansion angle of the coaxial fiber-laden flow as the Weber number and the ratio of melt film velocity to blowing air velocity are increased. The fiberization efficiency (ratio of fiber mass deposited on the collecting mesh to the mass of melt poured) is affected by the impingement position and flow rate of melt as well as the Weber number of melt film. The optimum efficiency was attained at 30° (1 o’clock) impingement position and the ratio of melt film to blowing air flow velocity close to unity.
{"title":"Analogue Experimental Study of Fiber Formation on Two-Wheel Spinner","authors":"B. Bizjan, B. Širok, M. Blagojevič","doi":"10.5545/sv-jme.2020.6557","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6557","url":null,"abstract":"In this paper, the process of mineral fiber formation was investigated experimentally on a two-wheel spinner by means of high-speed imaging. Analogue isomalt melt was fiberized at different rotational speeds of spinner wheels, melt flow rates and impingement positions so that the fiberization process was dynamically similar to an industrial mineral wool production process. Images of fiber formation and transport reveal highly complex dynamics of these processes, as fibers mostly occur in form of 3D mutually intertwined structures such as clusters, strands and veils periodically shedding from the melt film. Despite the complexity of flow structures, there is a clear trend of increasing mean fiber length and expansion angle of the coaxial fiber-laden flow as the Weber number and the ratio of melt film velocity to blowing air velocity are increased. The fiberization efficiency (ratio of fiber mass deposited on the collecting mesh to the mass of melt poured) is affected by the impingement position and flow rate of melt as well as the Weber number of melt film. The optimum efficiency was attained at 30° (1 o’clock) impingement position and the ratio of melt film to blowing air flow velocity close to unity.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"341 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122324336","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 : 2020-05-15DOI: 10.5545/sv-jme.2019.6499
A. Parvaresh, M. Mardani
This paper presents a data-driven approach that utilizes the gathered experimental data to model and control a test rig constructed for the high-powered gearboxes. For simulating a wide variety of operational conditions, the test rig should be capable of providing different speeds and torques; this is possible using a torque-applying system. For this purpose, Electro-Hydraulic Actuators (EHAs) are used. Since applying accurate torque is a crucial demand as it affects the performance evaluation of the gearboxes, precise modelling of the actuation system along with a high-performance controller are required. In order to eliminate the need to solve complex nonlinear equations of EHA that originate from friction, varying properties of flow and similar, a data-driven system based on neural networks is used for modelling. In this manner, the model of the system, which captures the whole dynamic of the system, can be obtained without any simplifying assumptions. The model is validated with experimental data, and the learning factors are set to zero to reduce the high computational costs. After that, another network of neurons is used as a controller. The performance of the proposed controller under normal conditions and in the presence of disturbances are investigated. The results show a good tracking of this controller for various reference inputs in different conditions with acceptable characteristics. Additionally, the obtained results are compared with a conventional proportional-integral-derivative (PID) controller results, and the superior features of the proposed scheme is concluded.
{"title":"Data-Driven Model-Free Control of Torque-Applying System for a Mechanically Closed-Loop Test Rig Using Neural Networks","authors":"A. Parvaresh, M. Mardani","doi":"10.5545/sv-jme.2019.6499","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6499","url":null,"abstract":"This paper presents a data-driven approach that utilizes the gathered experimental data to model and control a test rig constructed for the high-powered gearboxes. For simulating a wide variety of operational conditions, the test rig should be capable of providing different speeds and torques; this is possible using a torque-applying system. For this purpose, Electro-Hydraulic Actuators (EHAs) are used. Since applying accurate torque is a crucial demand as it affects the performance evaluation of the gearboxes, precise modelling of the actuation system along with a high-performance controller are required. In order to eliminate the need to solve complex nonlinear equations of EHA that originate from friction, varying properties of flow and similar, a data-driven system based on neural networks is used for modelling. In this manner, the model of the system, which captures the whole dynamic of the system, can be obtained without any simplifying assumptions. The model is validated with experimental data, and the learning factors are set to zero to reduce the high computational costs. After that, another network of neurons is used as a controller. The performance of the proposed controller under normal conditions and in the presence of disturbances are investigated. The results show a good tracking of this controller for various reference inputs in different conditions with acceptable characteristics. Additionally, the obtained results are compared with a conventional proportional-integral-derivative (PID) controller results, and the superior features of the proposed scheme is concluded.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127219724","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 : 2020-04-15DOI: 10.5545/sv-jme.2019.6510
A. K. Babu, G. Kumaresan, V. Antony Aroul Raj, R. Velraj
The design of a batch drying chamber with multiple trays for the thin-layer drying of fragile, heat-sensitive food materials, such as edible leaves, is a challenging task. It is essential to ensure good air distribution with minimum pressure drop in all the compartments of the drying chamber to obtain uniform drying of the product. In the present work, a drying chamber that was optimized from different configurations using computational fluid dynamics (CFD) software was fabricated and tested in the heat pump dryer. The experimental investigation was carried out with an optimized configuration for the temperature range of 50 ºC to 60 ºC, the relative humidity range of 20 % to 12 %, and air velocities of 1.41 m/s, 2.39 m/s, and 3.24 m/s. These optimal operating conditions were chosen based on an extensive literature survey on leaf drying. It was found that the drying process took place only in the falling rate period, fully controlled by the mechanism of liquid diffusion. The effects of air velocity on the performance parameters of the dryer were studied. Calculations based on the mean average parameters of the experimental data showed that a relatively higher heat utilization factor (0.17), moisture extraction ratio (0.375 kg/h), specific moisture extraction ratio (0.1529 kg/(kWh)), coefficient of performance (4.60), drying efficiency (76.23 %) and lower specific energy consumption (1.16 kW/kg) were obtained for a moderate drying velocity of 2.39 m/s in the heat pump drying process due to higher convection mass and heat transfer effects. Drying curves were plotted for different drying conditions and discussed. The findings were in agreement with those of many earlier research studies listed in the references section. The tested drying chamber can be used for drying all kinds of leaves in a heat pump dryer.
{"title":"Experimental Investigations of Thin-layer Drying of Leaves in a Heat-Pump Assisted Tray-type Batch Drying Chamber","authors":"A. K. Babu, G. Kumaresan, V. Antony Aroul Raj, R. Velraj","doi":"10.5545/sv-jme.2019.6510","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6510","url":null,"abstract":"The design of a batch drying chamber with multiple trays for the thin-layer drying of fragile, heat-sensitive food materials, such as edible leaves, is a challenging task. It is essential to ensure good air distribution with minimum pressure drop in all the compartments of the drying chamber to obtain uniform drying of the product. In the present work, a drying chamber that was optimized from different configurations using computational fluid dynamics (CFD) software was fabricated and tested in the heat pump dryer. The experimental investigation was carried out with an optimized configuration for the temperature range of 50 ºC to 60 ºC, the relative humidity range of 20 % to 12 %, and air velocities of 1.41 m/s, 2.39 m/s, and 3.24 m/s. These optimal operating conditions were chosen based on an extensive literature survey on leaf drying. It was found that the drying process took place only in the falling rate period, fully controlled by the mechanism of liquid diffusion. The effects of air velocity on the performance parameters of the dryer were studied. Calculations based on the mean average parameters of the experimental data showed that a relatively higher heat utilization factor (0.17), moisture extraction ratio (0.375 kg/h), specific moisture extraction ratio (0.1529 kg/(kWh)), coefficient of performance (4.60), drying efficiency (76.23 %) and lower specific energy consumption (1.16 kW/kg) were obtained for a moderate drying velocity of 2.39 m/s in the heat pump drying process due to higher convection mass and heat transfer effects. Drying curves were plotted for different drying conditions and discussed. The findings were in agreement with those of many earlier research studies listed in the references section. The tested drying chamber can be used for drying all kinds of leaves in a heat pump dryer.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134641219","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 : 2020-04-15DOI: 10.5545/sv-jme.2020.6563
Branislav Panić, J. Klemenc, M. Nagode
Condition monitoring and fault detection are nowadays popular topic. Different loads, enviroments etc. affect the components and systems differently and can induce the fault and faulty behaviour. Most of the approaches for the fault detection rely on the use of the good classification method. Gaussian mixture model based classification are stable and versatile methods which can be applied to a wide range of classification tasks. The main task is the estimation of the parameters in the Gaussian mixture model. Those can be estimated with various techniques. Therefore, the Gaussian mixture model based classification have different variants which can vary in performance. To test the performance of the Gaussian mixture model based classification variants and general usefulness of the Gaussian mixture model based classification for the fault detection, we have opted to use the bearing fault classification problem. Additionally, comparisons with other widely used non-parametric classification methods are made, such as support vector machines and neural networks. The performance of each classification method is evaluated by multiple repeated k-fold cross validation. From the results obtained, Gaussian mixture model based classification methods are shown to be competitive and efficient methods and usable in the field of fault detection and condition monitoring.
{"title":"Gaussian Mixture Model Based Classification Revisited: Application to the Bearing Fault Classification","authors":"Branislav Panić, J. Klemenc, M. Nagode","doi":"10.5545/sv-jme.2020.6563","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6563","url":null,"abstract":"Condition monitoring and fault detection are nowadays popular topic. Different loads, enviroments etc. affect the components and systems differently and can induce the fault and faulty behaviour. Most of the approaches for the fault detection rely on the use of the good classification method. Gaussian mixture model based classification are stable and versatile methods which can be applied to a wide range of classification tasks. The main task is the estimation of the parameters in the Gaussian mixture model. Those can be estimated with various techniques. Therefore, the Gaussian mixture model based classification have different variants which can vary in performance. To test the performance of the Gaussian mixture model based classification variants and general usefulness of the Gaussian mixture model based classification for the fault detection, we have opted to use the bearing fault classification problem. Additionally, comparisons with other widely used non-parametric classification methods are made, such as support vector machines and neural networks. The performance of each classification method is evaluated by multiple repeated k-fold cross validation. From the results obtained, Gaussian mixture model based classification methods are shown to be competitive and efficient methods and usable in the field of fault detection and condition monitoring.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114653466","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 : 2020-04-15DOI: 10.5545/sv-jme.2019.6285
V. Nguyen, V. Nguyen, V. Pham
Tool wear identification plays an important role in improving product quality and productivity in the manufacturing industry. The actual tool wear status with input cutting parameters may cause different levels of spindle vibration during the machining process. This research proposes an architecture comprising a deep learning network (DLN) to identify the actual wear state of machining tool. Firstly, data on spindle vibration signals are obtained from an acceleration sensor. The data are then pre-processed using the fast Fourier transform (FFT) method to reveal the relevant outstanding features in the frequency domain. Finally, the DLN is constructed based on stacked auto-encoders (SAE) and softmax, which is trained with the input data on the vibration features of the respective tool wear state. This DLN architecture is then used to identify the actual wear statuses of machining tool. The experimental results from the collected data show that the proposed DLN architecture is capable of identifying actual tool wear with high accuracy.
{"title":"Deep Stacked Auto-Encoder Network Based Tool Wear Monitoring in the Face Milling Process","authors":"V. Nguyen, V. Nguyen, V. Pham","doi":"10.5545/sv-jme.2019.6285","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6285","url":null,"abstract":"Tool wear identification plays an important role in improving product quality and productivity in the manufacturing industry. The actual tool wear status with input cutting parameters may cause different levels of spindle vibration during the machining process. This research proposes an architecture comprising a deep learning network (DLN) to identify the actual wear state of machining tool. Firstly, data on spindle vibration signals are obtained from an acceleration sensor. The data are then pre-processed using the fast Fourier transform (FFT) method to reveal the relevant outstanding features in the frequency domain. Finally, the DLN is constructed based on stacked auto-encoders (SAE) and softmax, which is trained with the input data on the vibration features of the respective tool wear state. This DLN architecture is then used to identify the actual wear statuses of machining tool. The experimental results from the collected data show that the proposed DLN architecture is capable of identifying actual tool wear with high accuracy.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129457556","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 : 2020-03-15DOI: 10.5545/sv-jme.2019.6418
Matej Kranjec, Jernej Korinšek, M. Ambrož, R. Kunc
The aim of this study is to verify whether a Raspberry Pi 3 B+ can be utilized as a low-cost device for controlling a tensile-testing device used for material research purposes. A list of requirements based on already-available hardware was drawn up, which the new control system had to fulfil. To connect all the necessary equipment, a connection board was constructed, and some additional hardware was acquired for the system to be able to perform all the necessary tasks. The whole controlling system was also put in a small enclosure to make it portable. The control-system software was written in C++ using the Pigpio library. The developed system was then tested, and the results were compared to a commercially available Instron 8802 device. A comparison of the results shows that the upgraded equipment can produce comparable results to commercially available devices and is sufficiently accurate to be applied for research purposes for the characterization of soft tissues and other materials.
{"title":"Control System for a Tensile-Testing Device Using Low-Cost Hardware and Open-Source Software","authors":"Matej Kranjec, Jernej Korinšek, M. Ambrož, R. Kunc","doi":"10.5545/sv-jme.2019.6418","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6418","url":null,"abstract":"The aim of this study is to verify whether a Raspberry Pi 3 B+ can be utilized as a low-cost device for controlling a tensile-testing device used for material research purposes. A list of requirements based on already-available hardware was drawn up, which the new control system had to fulfil. To connect all the necessary equipment, a connection board was constructed, and some additional hardware was acquired for the system to be able to perform all the necessary tasks. The whole controlling system was also put in a small enclosure to make it portable. The control-system software was written in C++ using the Pigpio library. The developed system was then tested, and the results were compared to a commercially available Instron 8802 device. A comparison of the results shows that the upgraded equipment can produce comparable results to commercially available devices and is sufficiently accurate to be applied for research purposes for the characterization of soft tissues and other materials.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129156633","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 : 2019-12-20DOI: 10.5545/sv-jme.2019.6156
Elvis Hozdić, Dominik Kozjek, P. Butala
Cyber-physical systems (CPSs) open up new perspectives for the design, development, implementation, and operation of manufacturing systems and will enable a paradigm shift in manufacturing. The objective of this research is to develop a new concept of cyber-physical production systems (CPPSs) and, on this basis, to address the issue of management and control, which is crucial for the effective and efficient operation of manufacturing systems. A new model of CPPS is proposed. The model integrates digitalized production planning, scheduling, and control functions with a physical part of manufacturing system and enables the self-organization of the elements in production. A case study demonstrates feasibility of the approach through the use of simulation experiments, which are based on real industrial data collected from a company that produces industrial and energy equipment.
{"title":"A Cyber-Physical Approach to the Management and Control of Manufacturing Systems","authors":"Elvis Hozdić, Dominik Kozjek, P. Butala","doi":"10.5545/sv-jme.2019.6156","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6156","url":null,"abstract":"Cyber-physical systems (CPSs) open up new perspectives for the design, development, implementation, and operation of manufacturing systems and will enable a paradigm shift in manufacturing. The objective of this research is to develop a new concept of cyber-physical production systems (CPPSs) and, on this basis, to address the issue of management and control, which is crucial for the effective and efficient operation of manufacturing systems. A new model of CPPS is proposed. The model integrates digitalized production planning, scheduling, and control functions with a physical part of manufacturing system and enables the self-organization of the elements in production. A case study demonstrates feasibility of the approach through the use of simulation experiments, which are based on real industrial data collected from a company that produces industrial and energy equipment.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"2002 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125762624","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 : 2019-12-20DOI: 10.5545/sv-jme.2019.6244
E. Zavrl, Gašper Zupanc, U. Stritih, M. Dovjak
The trend of lightweight framed building structures is gaining in popularity. Due to lower accumulation capability and thermal stability, buildings might be inclined to higher risk of overheating. The purpose of this study is to investigate overheating in lightweight framed buildings from the aspect of thermal comfort and energy efficiency in cooling season. Single-family house was modelled using DesignBuilder™ and located in moderate climate (Ljubljana, Slovenia). Heavyweight structure was compared to lightweight structure coupled with all 14 variations of phase change materials (PCM). Different strategies of PCM encapsulation (microencapsulated plasterboards, macroencapsulated additional layer), melting points (23°C, 24°C, 25°C, 26°C, 27°C), capacities (M182, M91 M51, M27) and thicknesses (125 mm, 250 mm) of PCM were investigated and compared. The best passive solution was primarily evaluated based on the thermal comfort characteristics: average zone operative temperature (To) bends in cooling season. Secondarily, the additional energy needed for cooling within each solution was compared to the maximum allowed annual energy consumed for cooling specified in legislation. Consequently, the most influential parameter was the melting point of the PCM structure. Based on the chosen criteria, the overheating was significantly reduced using macroencapsulated layer with melting point of 24°C and minimum capacity of M51 (max. To 26.3°C). Heavyweight structure enabled lower To (27.1°C) in the building compared to microencapsulated plasterboard solution with melting point at 23°C and thickness of 250 mm (28.8°C). Correctly designed passive solution can be used for the improvement of the design strategy and legislation towards overheating prevention.
{"title":"Overheating Reduction in Lightweight Framed Buildings\u0000with Application of Phase Change Materials","authors":"E. Zavrl, Gašper Zupanc, U. Stritih, M. Dovjak","doi":"10.5545/sv-jme.2019.6244","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6244","url":null,"abstract":"The trend of lightweight framed building structures is gaining in popularity. Due to lower accumulation capability and thermal stability, buildings might be inclined to higher risk of overheating. The purpose of this study is to investigate overheating in lightweight framed buildings from the aspect of thermal comfort and energy efficiency in cooling season. Single-family house was modelled using DesignBuilder™ and located in moderate climate (Ljubljana, Slovenia). Heavyweight structure was compared to lightweight structure coupled with all 14 variations of phase change materials (PCM). Different strategies of PCM encapsulation (microencapsulated plasterboards, macroencapsulated additional layer), melting points (23°C, 24°C, 25°C, 26°C, 27°C), capacities (M182, M91 M51, M27) and thicknesses (125 mm, 250 mm) of PCM were investigated and compared. The best passive solution was primarily evaluated based on the thermal comfort characteristics: average zone operative temperature (To) bends in cooling season. Secondarily, the additional energy needed for cooling within each solution was compared to the maximum allowed annual energy consumed for cooling specified in legislation. Consequently, the most influential parameter was the melting point of the PCM structure. Based on the chosen criteria, the overheating was significantly reduced using macroencapsulated layer with melting point of 24°C and minimum capacity of M51 (max. To 26.3°C). Heavyweight structure enabled lower To (27.1°C) in the building compared to microencapsulated plasterboard solution with melting point at 23°C and thickness of 250 mm (28.8°C). Correctly designed passive solution can be used for the improvement of the design strategy and legislation towards overheating prevention.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132622228","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 : 2019-11-18DOI: 10.5545/sv-jme.2019.6351
L. Sterle, D. Grguraš, M. Kern, F. Pušavec
Efficient cooling and lubrication techniques are required to obtain sustainable machining of difficult-to-cut materials, which are the pillars of aerospace, automotive, medical and nuclear industries. Cryogenic machining with the assistance of lubricated Liquid Carbon Dioxide (LCO2) is a novel approach for sustainable manufacturing without the use of harmful water-based metalworking fluids (MWFs). In case of unavoidable use of MWFs under high pressure, such as turning finishing processes of difficult-to-cut materials, the pulsating high pressure delivery of MWFs prolongs the tool life and enables the control over chip length to prevent surface damage of high value-added parts. In this paper, sustainability assessment of both advanced principles was carried out, considering overall costs and operational safety. Experimental tests were executed on difficult-to-cut materials in comparison to conventional flood lubrication. For both techniques, longer tool life compared to flood lubrication was observed additional cleaner production and higher part quality led to reduced long-term overall costs. These advanced machining technologies are also operation safe, proving to be a sustainable alternative to conventional machining.
{"title":"Sustainability Assessment of Advanced Machining Technologies","authors":"L. Sterle, D. Grguraš, M. Kern, F. Pušavec","doi":"10.5545/sv-jme.2019.6351","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6351","url":null,"abstract":"Efficient cooling and lubrication techniques are required to obtain sustainable machining of difficult-to-cut materials, which are the pillars of aerospace, automotive, medical and nuclear industries. Cryogenic machining with the assistance of lubricated Liquid Carbon Dioxide (LCO2) is a novel approach for sustainable manufacturing without the use of harmful water-based metalworking fluids (MWFs). In case of unavoidable use of MWFs under high pressure, such as turning finishing processes of difficult-to-cut materials, the pulsating high pressure delivery of MWFs prolongs the tool life and enables the control over chip length to prevent surface damage of high value-added parts. In this paper, sustainability assessment of both advanced principles was carried out, considering overall costs and operational safety. Experimental tests were executed on difficult-to-cut materials in comparison to conventional flood lubrication. For both techniques, longer tool life compared to flood lubrication was observed additional cleaner production and higher part quality led to reduced long-term overall costs. These advanced machining technologies are also operation safe, proving to be a sustainable alternative to conventional machining.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125851972","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 : 2019-11-18DOI: 10.5545/sv-jme.2019.6465
This special issue of SV-JME celebrates the 100th anniversary of the UL and the studies of mechanical engineering and presents the research achievements of Slovenian UL scientists in the field of mechanical engineering. We have become a part of Slovenian intelligence objectively setting the boundaries for the development and advance of the Slovenian nation.
{"title":"Editorial: Centenary of the University of Ljubljana and the study of mechanical engineering","authors":"","doi":"10.5545/sv-jme.2019.6465","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6465","url":null,"abstract":"This special issue of SV-JME celebrates the 100th anniversary of the UL and the studies of mechanical engineering and presents the research achievements of Slovenian UL scientists in the field of mechanical engineering. We have become a part of Slovenian intelligence objectively setting the boundaries for the development and advance of the Slovenian nation.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134231534","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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