Strojniški vestnik – Journal of Mechanical Engineering最新文献_第6页

Analogue Experimental Study of Fiber Formation on Two-Wheel Spinner 双轮纺丝机成纤维的模拟实验研究

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-05-15 DOI: 10.5545/sv-jme.2020.6557

B. Bizjan, B. Širok, M. Blagojevič

{"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}

引用次数: 0

Data-Driven Model-Free Control of Torque-Applying System for a Mechanically Closed-Loop Test Rig Using Neural Networks 基于神经网络的机械闭环试验台加矩系统数据驱动无模型控制

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-05-15 DOI: 10.5545/sv-jme.2019.6499

A. Parvaresh, M. Mardani

{"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}

引用次数: 2

Experimental Investigations of Thin-layer Drying of Leaves in a Heat-Pump Assisted Tray-type Batch Drying Chamber 热泵辅助托盘式间歇干燥室叶片薄层干燥的实验研究

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-04-15 DOI: 10.5545/sv-jme.2019.6510

A. K. Babu, G. Kumaresan, V. Antony Aroul Raj, R. Velraj

{"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}

引用次数: 3

Gaussian Mixture Model Based Classification Revisited: Application to the Bearing Fault Classification 基于高斯混合模型的分类重述:在轴承故障分类中的应用

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-04-15 DOI: 10.5545/sv-jme.2020.6563

Branislav Panić, J. Klemenc, M. Nagode

{"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}

引用次数: 16

Deep Stacked Auto-Encoder Network Based Tool Wear Monitoring in the Face Milling Process 基于深度堆叠自编码器网络的面铣削过程刀具磨损监测

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-04-15 DOI: 10.5545/sv-jme.2019.6285

V. Nguyen, V. Nguyen, V. Pham

引用次数: 10

Control System for a Tensile-Testing Device Using Low-Cost Hardware and Open-Source Software 基于低成本硬件和开源软件的拉伸试验装置控制系统

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-03-15 DOI: 10.5545/sv-jme.2019.6418

Matej Kranjec, Jernej Korinšek, M. Ambrož, R. Kunc

引用次数: 4

A Cyber-Physical Approach to the Management and Control of Manufacturing Systems 制造系统管理与控制的信息物理方法

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2019-12-20 DOI: 10.5545/sv-jme.2019.6156

Elvis Hozdić, Dominik Kozjek, P. Butala

引用次数: 13

Overheating Reduction in Lightweight Framed Buildingswith Application of Phase Change Materials 相变材料在轻量化框架建筑中的应用

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2019-12-20 DOI: 10.5545/sv-jme.2019.6244

E. Zavrl, Gašper Zupanc, U. Stritih, M. Dovjak

{"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}

引用次数: 4

Sustainability Assessment of Advanced Machining Technologies 先进加工技术的可持续性评估

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2019-11-18 DOI: 10.5545/sv-jme.2019.6351

L. Sterle, D. Grguraš, M. Kern, F. Pušavec

{"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}

引用次数: 5

Editorial: Centenary of the University of Ljubljana and the study of mechanical engineering 社论:卢布尔雅那大学百年校庆与机械工程研究

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2019-11-18 DOI: 10.5545/sv-jme.2019.6465

引用次数: 0