{"title":"Analysis and Control of Single Phase Grid Connected Modular Multilevel Converter in Per Unit","authors":"Elif Beyhan, Eyup Akpinar","doi":"10.26701/ems.622397","DOIUrl":"https://doi.org/10.26701/ems.622397","url":null,"abstract":"In this paper, a mathematical model and control methods of a modular multilevel converter are examined in per unit. Some control algorithms, like a sorting algorithm, circulating current control, proportional resonant controller and pulse width modulation techniques which are applicable on this converter are investigated. The average value model is used in per unit for the converter and it is combined with circulating current control method and propotional resonant current controller to suppress the second harmonic component in the circulating current. The effect of the circulating current harmonics on the resonance frequency is investigated. A Matlab/Simulink model is prepared for the simulation of converter modeled on the approach of the average value model and the results are generated from the simulation and they are discussed.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131027468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Detailed Thermal Design and Control of an Observation Satellite in Low Earth Orbit","authors":"Hilmi Sundu, N. Doner","doi":"10.26701/ems.730201","DOIUrl":"https://doi.org/10.26701/ems.730201","url":null,"abstract":"The thermal environment in space has challenging conditions in which include vacuum, low pressure, atomic oxygen, extremely hot and cold. Satellites consist of electronic equipments and these equipments should be maintained at a certain temperature range during the operation period. Therefore, thermal design and control of observation satellites at Low Earth Orbit in space are considerably important. In our study, we studied thermal design and analysis of a Low Earth Orbit (LEO) observation satellites. A satellite was designed and modeled with Systema-Thermica v.4.8.P1 using Monte-Carlo Ray Tracing Method. The analyses were performed for two extreme scenarios: i) the worst hot, and ii) the worst cold situations. The areas, temperatures, and locations of the radiators on the satellite panels were analyzed by the considered extreme scenarios. The powers and operating conditions of the heaters were evaluated according to the worst cold scenario. It was seen that the temperatures of the electronic equipments on the satellite are to be in the optimum temperature range during the observation process.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122030299","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}
Osasumwen Godswill Ogiemudia, A. Ikpe, Lucky Efe Chughiefe
{"title":"Design and Fabrication of a Modular Melon Depodding Machine for Optimum Performance in Nigerian Agricultural Sector","authors":"Osasumwen Godswill Ogiemudia, A. Ikpe, Lucky Efe Chughiefe","doi":"10.26701/ems.729747","DOIUrl":"https://doi.org/10.26701/ems.729747","url":null,"abstract":"The traditional methods of depodding melon pods to extract the edible seeds is a time consuming and tedious process. A melon depodding machine was therefore designed, fabricated and tested for use in Nigeria. The fabricated machine had the following operating units: depodding chamber, power system, feeding hopper, supporting frame, electric motor, gear shaft, discharge unit etc. The average mass of melon pod of 1.671 kg and the average diameter of the melon pod of 139.25 mm were obtained experimentally. From the performance test carried out on the machine, average percentage of depodded seeds of 91.1255%, average percentage of undepodded seeds of 7.2915%, the average percentage of damaged seeds of 1.5835% and the average percentage of useful seeds of 98.4165%. Considering the aforementioned results, the melon depodding machine designed in this study can perform optimally in both domestic and commercial level in Nigeria.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127003803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Torsional Vibration Analysis of Carbon Nanotubes Using Maxwell and Kelvin-Voigt Type Viscoelastic Material Models","authors":"M. Arda","doi":"10.26701/ems.669495","DOIUrl":"https://doi.org/10.26701/ems.669495","url":null,"abstract":"Torsional dynamic analysis of viscoelastic Carbon Nanotubes (CNT) has been carried out in the present work. Maxwell and Kelvin-Voigt type viscoelasticity are considered in the modeling of viscoelastic material. Nonlocal Elasticity Theory is used in the formulation of governing equation of motion and boundary conditions. Viscoelasticity and nonlocal effects of structure on the free torsional vibration of CNTs have been investigated. Clamped-clamped and clamped-free boundary conditions are considered. Present study results could be useful in design of nano-medicine delivery applications.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"371 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122774890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the Way to Real Applications: Aluminum Matrix Syntactic Foams","authors":"Çağın Bolat, İ. C. Akgün, A. Gökşenli","doi":"10.26701/ems.703619","DOIUrl":"https://doi.org/10.26701/ems.703619","url":null,"abstract":"In recent times, aluminum matrix syntactic foams (AMSFs) have become considerably attractive for many industries such as automotive, aviation, aerospace and composite sector due to their features of low density, good compression strength, perfect energy absorption capacity and good ductility. Since the AMSF includes filler materials providing high porosity, it can be also named as composite foam and can be placed between traditional metal foams and particle reinforced composites. Glass and ceramic hollow spheres, fly ash cenospheres and ceramic porous materials are usually used in the AMSFs, but, lately, different types of fillers being cheaper and stronger have also being investigated. Although many scientific efforts have been made for the last decade to understand mechanical and physical properties of these advanced materials, studies have mainly been performed on relatively small size samples and remained in laboratory. Therefore, there is still room for improvement in terms of fabrication techniques. In this paper, our aims are to scrutinize newest studies about ASMFs, to create new viewpoints and to introduce an alternative bright perspective for probable real applications.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124107533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Estimation of the Experimental Drying Performance Parameters Using Polynomial SVM and ANN Models","authors":"Kamil Neyfel Çerçi, D. B. Saydam, E. Hürdoğan","doi":"10.26701/ems.692149","DOIUrl":"https://doi.org/10.26701/ems.692149","url":null,"abstract":"The utilization of solar energy in Turkey is very popular because of yearly high solar radiation compared to other countries. One of the common usage area of solar energy is food drying processes. Foods are generally dried under direct sunlight. However, the quality of the dried product exposed to solar radiation reduces. Additionally, the food product dried in outdoors is also exposed to the negative effects of the external environment and thus adversely affects the product quality. In order to overcome these problems, many studies are carried out on solar assisted drying systems. It is very important to calculate or modeling the drying parameters for the design of solar assisted drying systems. In recent years, interest on calculative intelligence methods increases due to the fact that it has high predictive power in modeling of systems. In this study, performance parameters such as solar collector efficiency (ηc), drying rate (DR) and convective heat transfer coefficient (hc) obtained from a solar energy assisted dryer for different products were estimated by Support Vector Machine (SVM) and Artificial Neural Network (ANN) models. The accuracy criteria of the predicted results for each model were determined and compared. It was shown from the results that the best converging models of DR and ηc parameters were ANN and SVMC, respectively. However, it was observed that SVML was the best convergent model for hc values obtained from apple product, and ANN model was the best convergent model for hc values obtained from other products.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125151563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of Thermal Behavior of Lithium-Ion Batteries under Different Loads","authors":"Ceyda Kök, A. Alkaya","doi":"10.26701/ems.635707","DOIUrl":"https://doi.org/10.26701/ems.635707","url":null,"abstract":"In this study, the thermal behavior and performance of pouch type Lithium-Ion Batteries (LIB) which are used in Hybrid Electric Vehicles (HEVs) and Electrical Vehicles (EVs) has been investigated at different discharge rates based on numerical simulations. Numerical simulation was performed through a traditional software package using the dual potential Multi-Scale Multi-Dimensional (MSMD) battery model to analyze the cell discharge behavior and investigate its thermal performance. When the battery load is increased, non-uniform thermal distribution and temperature rise has been observed. Non-uniform thermal distribution causes loss of capacity and performance in the battery. Therefore, an accurate and effective cooling system is required to eliminate non-uniform temperature distribution. This study is a preliminary preparation for cooling system design.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128838888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of Plasticity Models Using Uniaxial Tensile Test","authors":"A. Ünlü, E. Esener, Mehmet Firat","doi":"10.26701/ems.736492","DOIUrl":"https://doi.org/10.26701/ems.736492","url":null,"abstract":"In this study, it is aimed to evaluate plasticity model prediction performance for plastic behavior of materials using a uniaxial tensile test. For this purpose, von Mises, Hill-48, Hill-93, Barlat-89 and Hu -2003 plasticity models are studied, and DC04, DP780, 6000 series aluminum alloy are used as materials. Tensile tests are performed with three directions (rolling, diagonal, transverse), and mechanical properties of materials are obtained. In addition, anisotropy coefficients of materials are calculated by uniaxial tensile tests. Validation of plasticity models is performed using obtained material parameters. Yield locus and yield stresses-anisotropy coefficients depends on directions are used in evaluation of plasticity models. As a result of this study, Hu-2003 showed the best modeling performance for all materials.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117126591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Scalar Dielectric Constant Extraction of Planar Materials from Reflection Measurements","authors":"B. Colak","doi":"10.26701/ems.623406","DOIUrl":"https://doi.org/10.26701/ems.623406","url":null,"abstract":"Industrial plastics are widely used in warfare electromechanical systems to protect the internal electronic circuitry from environmental effects. Depending the purpose of the warfare system, the surface interaction with electromagnetic fields play a key role and the main parameter that determines reflection and the shielding of the electromagnetic fields from material surface is the dielectric constant of the material itself. In this paper, extraction of scalar dielectric constant from electromagnetic reflection measurement using an alternative two standard calibration technique in a low cost aluminum compact chamber is obtained. Calibration technique uses time domain measurements and converts them to frequency domain. Especially in R&D phase of electromechanical integration of warfare systems, this technique is quite useful where the exact values of dielectric constants of planar industrial plastics are not required. Obtained reflection coefficient error level is 0.67dB for 10mm while it reaches 1.62dB for 40mm thickness materials. It is shown that calculated values are in good agreement with the reference measurement method performed by precision airline setup Agilent 85050C.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131814247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Dynamic Approach In Production Management for Automotive Field","authors":"Banu Özkeser","doi":"10.26701/EMS.678821","DOIUrl":"https://doi.org/10.26701/EMS.678821","url":null,"abstract":"Solution proposals, based on dynamic approaches, can easily take place of the existing situations owing to the unlimited customer requests. Therefore, this may lead to a rapid transformation, triggering the manufacturing society to deal with the requirements for a sustainable competitive advantage. Especially, the automotive field, deeply affected by the fast-changing demands, brings about some new business models superimposing the existing ones because of the technology-intensive production management. This progress makes the world’s expectation be higher depending on process innovation and minimizing the lead time may be declared as one of the top satisfaction points in the market. This paper, including the review of different manufacturing methods, highlights the awareness of the best implementations along with the production management in the automotive field. Moreover, it aims to develop a process innovation by designing a dynamic algorithm. The content of the paper, depending on multiple machines with multiple orders, is completed in all details by analyzing the gaps of the literature review. In the second step, the original algorithm is formed by taking into consideration the priorities. The achieved analysis is based on the main criteria and subcomponents of the scheduling of the manufacturing process. Finally, the algorithm, formed by four main priorities, leads the numerical implementations to be done in only one order and the results show that this approach can be a good way for minimization of total delays of orders.","PeriodicalId":373904,"journal":{"name":"European Mechanical Science","volume":"815 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114845283","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}