Strojniški vestnik – Journal of Mechanical Engineering最新文献_第5页

Bristle Motion, Forces, and Related Vertical Translation for a Novel Electric Toothbrush Design 一种新型电动牙刷设计的刷毛运动、力和相关垂直平移

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-09-15 DOI: 10.5545/sv-jme.2020.6665

F. Goldschmidtboeing, U. Pelz, Karen Lynn Claire-Zimmet, Michael Wolf, R. Goerlach, P. Woias

引用次数: 2

Numerical Analysis with Experimental Validation of Single-Phase Fluid Flow in a Dimple Pattern Heat Exchanger Channel 凹坑式换热器通道内单相流体流动的数值分析与实验验证

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-09-15 DOI: 10.5545/sv-jme.2020.6776

Urban Močnik, B. Blagojevic, S. Muhič

{"title":"Numerical Analysis with Experimental Validation of Single-Phase Fluid Flow in a Dimple Pattern Heat Exchanger Channel","authors":"Urban Močnik, B. Blagojevic, S. Muhič","doi":"10.5545/sv-jme.2020.6776","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6776","url":null,"abstract":"A plate heat exchanger with a dimple pattern heat plate has a large number of dimples. The shape of dimples defines the characteristics of the plate heat exchanger. Although such heat exchangers have become increasingly popular due to their beneficial characteristics, knowledge of the flow characteristics in such kind of channel is poor. A good knowledge of the flow conditions inside of such channel is crucial for the successful and efficient development of new products. In this paper single-phase water flow in dimple pattern plate heat exchanger was investigated with application of computational fluid dynamics and laboratory experiments. Numerical analysis was performed with two turbulence models, Realizable - with enhanced wall treatment function and - SST. The first predicts a slightly smaller pressure drop and the second slightly larger compared to the results of laboratory measurements. Our research found that despite the relatively low velocity of the fluid, turbulent flow occurs in the channel due to its shape. We also found that there are two different flow regimes in the micro plate heat exchanger channel. The first regime is the regime that dominates the heat transfer, and the second is the regime where a recirculation zone appears behind the brazing point, which reduces the surface for heat transfer. The size of the second regime does not change significantly with the velocity of the fluid in the volume considered.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"6 19","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132805925","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

Dynamic Instability of a Wind Turbine Blade Due to Large Deflections: An Experimental Validation 风力机叶片大挠度动态不稳定性的实验验证

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-09-15 DOI: 10.5545/sv-jme.2020.6678

Andrés T. López-López, J. Robles-Ocampo, P. Sevilla-Camacho, Orlando Lastres-Danguillecourt, Jesús Muñiz, B. Pérez-Sariñana, Sergio de la Cruz

引用次数: 3

Convective Drying of Sewage Sludge Layer in Through-flow 污水污泥层通流对流干燥

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-09-15 DOI: 10.5545/sv-jme.2020.6717

Andraž Lipolt, B. Širok, M. Hočevar, L. Novak

{"title":"Convective Drying of Sewage Sludge Layer in Through-flow","authors":"Andraž Lipolt, B. Širok, M. Hočevar, L. Novak","doi":"10.5545/sv-jme.2020.6717","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6717","url":null,"abstract":"Drying of the sewage sludge layer was investigated in a convective laboratory dryer at air temperatures of 65 °C and 80 °C and air speeds of 0.53 m/s and 0.83 m/s. The sludge layer was formed by loading cylindrical extrudates on a grate of 0.5 m × 0.5 m size. The drying air was directed through the layer, as typically encountered in industrial belt dryers. Under such setup, the sludge layer structure and porosity significantly affect the air flow conditions and thus the drying rates. Shrinkage and cracking of the material during drying caused changes in the layer’s porous structure, that affected the pressure drop and the drag force due to passing of air through the layer. The decreasing of drag force over time was modeled by a simple function that showed excellent agreement to the selected measured data. The sludge layer drying kinetics was determined by fitting the measured data to the most common drying models. Two models, the modified Nadhari and the Wang Singh model, were determined as most suitable for modeling of drying curves. The total drying time per kilogram of sludge was modeled as a function of drying air temperature, drying air velocity and initial sludge dry matter content. The coefficient of determination (R2) of the model is 0.944. Total drying times between 43 minutes per kilogram and 76 minutes per kilogram of sludge were obtained for the investigated range of drying air conditions.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134395795","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

Enhancing the Optimization of the Selection of a Product Service System Scheme: A Digital Twin-Driven Framework 加强产品服务体系方案选择的优化:数字双驱动框架

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-09-15 DOI: 10.5545/sv-jme.2020.6621

Yan Li, Lianhui Li

{"title":"Enhancing the Optimization of the Selection of a Product Service System Scheme: A Digital Twin-Driven Framework","authors":"Yan Li, Lianhui Li","doi":"10.5545/sv-jme.2020.6621","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6621","url":null,"abstract":"A product service system (PSS) has been developed for manufacturing enterprises to provide users with personalized products and services. The optimization of PSS scheme selection is a key stage in the PSS design phase. Given the dynamic characteristics of the multi-dimensional influencing factors and their coupling relationships, we propose a digital twin-driven framework to enhance the optimization of PSS scheme selection. The framework is divided into a digital twin layer, an information layer, and an approach layer. The logical relationship between the three layers is given, and a quantitative PSS scheme selection optimization mechanism is designed. Fuzzy numbers and rough boundary intervals are integrated for the attribute value determination of the PSS scheme. A modified TOPSIS developed by replacing Euclidean distance with relational vector distance is adopted for the PSS scheme assessment. A case of an air purification PSS scheme selection optimization under the proposed digital twin driven framework is studied. It is shown that the designed PSS scheme selection optimization mechanism is effective and can be enhanced with the presented framework.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131240668","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: 18

Characterization of the Bonding Zone in AZ91/AlSi12 Bimetals Fabricated by Liquid-Solid Compound Casting Using Unmodified and Thermally Modified AlSi12 Alloy 未改性和热改性AlSi12合金液固复合铸造AZ91/AlSi12双金属的结合区表征

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-07-15 DOI: 10.5545/sv-jme.2020.6703

R. Mola, T. Bucki

{"title":"Characterization of the Bonding Zone in AZ91/AlSi12 Bimetals Fabricated by Liquid-Solid Compound Casting Using Unmodified and Thermally Modified AlSi12 Alloy","authors":"R. Mola, T. Bucki","doi":"10.5545/sv-jme.2020.6703","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6703","url":null,"abstract":"Liquid-solid compound casting was used to produce two types of AZ91/AlSi12 joints. The magnesium alloy was the cast material poured onto a solid aluminium alloy insert with an unmodified or modified structure. The bonding zone obtained for the unmodified insert was not uniform in thickness. There was a eutectic region (Mg17Al12 + a solid solution of Al in Mg) in the area closest to the AZ91. The region adjacent to the AlSi12 had a non-uniform structure with partly reacted Si particles surrounded by the Mg2Si phase and agglomerates of Mg2Si particles unevenly distributed in the Mg-Al intermetallic phases matrix. Cracks were detected in this region. In the AZ91/AlSi12 joint produced with a thermally modified AlSi12 insert, the bonding zone was uniform in thickness. The region closest to the AZ91 alloy also had a eutectic structure. However, significant microstructural changes were reported in the region adjacent to the modified AlSi12 alloy. The microstructure of the region was uniform with no cracks; the fine Mg2Si particles were evenly distributed over the Mg-Al intermetallic phase matrix. The study revealed that in both cases the microhardness of the bonding zone was several times higher than those of the individual alloys; however, during indenter loading, the bonding zone fabricated from modified AlSi12 alloy was less prone to cracking.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128456278","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

Needleless Electrospinning of PA6 Fibers: The Effect of Solution Concentration and Electrospinning Voltage on Fiber Diameter 无针静电纺丝PA6纤维:溶液浓度和静电纺丝电压对纤维直径的影响

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-07-15 DOI: 10.5545/sv-jme.2020.6713

Alexandra Aulova, M. Bek, L. Kossovich, I. Emri

{"title":"Needleless Electrospinning of PA6 Fibers: The Effect of Solution Concentration and Electrospinning Voltage on Fiber Diameter","authors":"Alexandra Aulova, M. Bek, L. Kossovich, I. Emri","doi":"10.5545/sv-jme.2020.6713","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6713","url":null,"abstract":"Needleless electrospinning is the process of forming thin material fibers from the open surface of its solution or melt in a strong electrostatic field. Electrospun non-woven materials are used in various applications that require specific fiber diameters and pore size distributions. Fiber diameter depends on the properties of the polymer solution and manufacturing conditions. A needleless electrospinning process using the Nanospider setup was investigated using the commonly used polyamide 6 (PA6) solution in a mixture of acetic and formic acids. Polymer solutions with different polymer concentrations were characterized by viscosity, surface tension and electrical conductivity. An increase in polymer content in the solution resulted in the exponential increase of the solution viscosity, polynomial increase of electrical conductivity and had almost no effect on surface tension. The effect of the polymer concentration in the solution, as well as electrospinning voltage on fiber diameter and diameter distribution, was investigated using scanning electron microscopy images. The average fiber diameter linearly increases with the increased polymer concentration and also demonstrates an increase with increased electrospinning voltage, although less pronounced. Therefore, a change in the PA6 solution concentration should be used for the robust adjustment of fiber diameter, while changes in electrospinning voltage are more appropriate for fine tuning the fiber diameter during the process of needleless electrospinning.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133344135","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

Structural Analysis and Size Optimization of a Fine-Blanking Press Frame Based on Sensitivity Analysis 基于灵敏度分析的精冲压力机机架结构分析及尺寸优化

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-06-15 DOI: 10.5545/sv-jme.2020.6564

Zhao Xinhao, Yanxiong Liu, L. Hua, Hua-jie Mao

引用次数: 2

An Experimental and Numerical Investigation of an Improved Shearing Process with Different Punch Characteristics 不同冲床特性改进剪切工艺的实验与数值研究

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-06-15 DOI: 10.5545/sv-jme.2020.6583

Mahmoud Gomah, M. Demiral

{"title":"An Experimental and Numerical Investigation of an Improved Shearing Process with Different Punch Characteristics","authors":"Mahmoud Gomah, M. Demiral","doi":"10.5545/sv-jme.2020.6583","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6583","url":null,"abstract":"Blanking and piercing shearing processes have been widely used to manufacture workpieces for industrial, commercial and testing purposes. During the operation, the punch is exposed to higher stresses and, due to the cycled contact of opposite surfaces, it can be worn significantly. As its surface directly affects the quality of sheet products and causes some surface defects, its performance plays a significant role. In this study, various tools with different characteristics were investigated for an improved shearing process. First, a novel punch with a hemispherical ball at the centre of its flat face was tested and compared with a conventional one. The process was simulated using ABAQUS/Explicit finite element (FE) program, in which the Johnson-Cook material model with its complementary damage model was used to represent the behaviour of the sheet material. Based on this, an optimum geometry for the proposed punch was determined. Secondly, the wear resistance of TiN, CrN, TiSiN, AlCrN and AlTiN coated punches, produced with physical vapour deposition (PVD) technique, and of the polycrystalline diamond compact (PDC) cutter were compared based on scanning electron microscope (SEM) micrographs after 1000 strokes under dry cutting conditions.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133166388","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: 6

Analysis of the Screening Accuracy of a Linear Vibrating Screen with a Multi-layer Screen Mesh 多层筛网直线振动筛筛分精度分析

Strojniški vestnik – Journal of Mechanical Engineering Pub Date : 2020-05-15 DOI: 10.5545/sv-jme.2019.6523

Yan Hongwei, Lin Yajie, Y. Fei, Peng Fangxian, Yang Xiong, Hou Xiangrong

{"title":"Analysis of the Screening Accuracy of a Linear Vibrating Screen with a Multi-layer Screen Mesh","authors":"Yan Hongwei, Lin Yajie, Y. Fei, Peng Fangxian, Yang Xiong, Hou Xiangrong","doi":"10.5545/sv-jme.2019.6523","DOIUrl":"https://doi.org/10.5545/sv-jme.2019.6523","url":null,"abstract":"This paper investigates the screening characteristics of the multi-layer vibrating screens. A portable linear screen with a three-layer screen mesh and the vibrating screening experimental platform were designed and simulated. Based on the discrete element method (DEM), the influences of the motor excitation frequency, the pulverized coal mass flow rate, and the shape of the particles on the screening accuracy of each layer of the screen and the total energy contained in the particles were analysed. The simulation analysis found that, during the vibration screening process, with the increase of the frequency of motor excitation, the screening accuracy of each screen layers increased first and then decreased. The ratio of the sieving accuracy of the first screen and the third screen is reduced first and then increased. The energy contained in the particles gradually increases. With the increased pulverized coal mass flow rate, the screening accuracy of each layer gradually decreased, while the ratio of the screening accuracy of the first layer to that of the third layer gradually increased. The energy contained in the particles gradually decreases. Similarly, the increased percentage of non-spherical particles generated slightly decreased screening accuracy and an increased ratio of the screening accuracy of the first and third screens. The particles also contain much less energy than spherical particles do. A simulation was carried out on the vibrating screening experimental platform with screening materials such as soybeans and red beans. The experimental results matched the discrete element simulation. The screening accuracy was proved to be higher when the excitation frequency lay in 18 Hz to 20 Hz, and the particles mass flow rate stayed below 0.4 kg/s. This study demonstrated that changing the shape of particles is a practical way of managing real screening work. It also provided a theoretical basis and reference for the design and applications of multi-layer vibrating screens.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"51 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":"115622332","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