Abstract The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.
{"title":"Computational Fluid Dynamics Analysis of an Evaporative Cooling System","authors":"N. Kapilan, M. Manjunath Gowda, H. Manjunath","doi":"10.1515/scjme-2016-0026","DOIUrl":"https://doi.org/10.1515/scjme-2016-0026","url":null,"abstract":"Abstract The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"117 - 124"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/scjme-2016-0026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67004289","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}
Abstract This paper contains results of transient analysis of airflow around the ACSR power line cross-section in unsymmetric multi-span. The forces applied to the power line are obtained from CFD simulations, where the wind induced vibration is studied. Effect of these forces to the maximal displacement of the power line and the maximal mechanical forces in the points of attachment are studied and evaluated.
{"title":"Numerical Calculation of Overhead Power Lines Dynamics","authors":"Roman Gogola, J. Murín, J. Hrabovský","doi":"10.1515/scjme-2016-0014","DOIUrl":"https://doi.org/10.1515/scjme-2016-0014","url":null,"abstract":"Abstract This paper contains results of transient analysis of airflow around the ACSR power line cross-section in unsymmetric multi-span. The forces applied to the power line are obtained from CFD simulations, where the wind induced vibration is studied. Effect of these forces to the maximal displacement of the power line and the maximal mechanical forces in the points of attachment are studied and evaluated.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"13 - 22"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/scjme-2016-0014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67003361","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}
Abstract This contribution explores how design changes can affect resistance of rail wagon seat-to-frame connections at impact test and proposes alternative way to construct such connections. Results were due to a nature of presented problem obtained by computer modelling using MSC Nastran with explicit finite element method solution invoked. Physical tests were also conducted and comparison with numerical results is presented.
{"title":"Modelling of Two-Seat Connection to the Frame of Rail Wagon in Terms of Resistance at Impact Test","authors":"R. Čech, P. Horyl, P. Maršálek","doi":"10.1515/scjme-2016-0024","DOIUrl":"https://doi.org/10.1515/scjme-2016-0024","url":null,"abstract":"Abstract This contribution explores how design changes can affect resistance of rail wagon seat-to-frame connections at impact test and proposes alternative way to construct such connections. Results were due to a nature of presented problem obtained by computer modelling using MSC Nastran with explicit finite element method solution invoked. Physical tests were also conducted and comparison with numerical results is presented.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"101 - 106"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67003772","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}
Abstract The conventional method for evaluation of the fatigue constants uses one set of experimental data from strain-controlled uniaxial fatigue tests. However, these constants do not ensure the compatibility conditions. The new 3D method retains the mathematical and physical relationships between curves considered. This paper presents a way of implementation of the identification procedure and shows results obtained for three types of materials.
{"title":"Identification of Fatigue Constants by Means of 3D Method","authors":"D. Ličková, R. Halama, Z. Poruba","doi":"10.1515/scjme-2016-0025","DOIUrl":"https://doi.org/10.1515/scjme-2016-0025","url":null,"abstract":"Abstract The conventional method for evaluation of the fatigue constants uses one set of experimental data from strain-controlled uniaxial fatigue tests. However, these constants do not ensure the compatibility conditions. The new 3D method retains the mathematical and physical relationships between curves considered. This paper presents a way of implementation of the identification procedure and shows results obtained for three types of materials.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"107 - 116"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67004181","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}
Abstract The main aim of the pilot study was to evaluate the relationship between degree of visual impairment of patient and his postural stability. The article contains basic explanation and requirements for stabilography research. The paper also describes statistic analysis of influence of visual impairment on postural stability opposed to control group (people perfectly sighted). These results allowed us to verify the approved research plan.
{"title":"A Pilot Study in Order to Examine the Relationship between the Degree of Visual Impairment of Patient and His Postural Stability","authors":"M. Jureczko, P. Jureczko, M. Krzysztofik","doi":"10.1515/scjme-2016-0017","DOIUrl":"https://doi.org/10.1515/scjme-2016-0017","url":null,"abstract":"Abstract The main aim of the pilot study was to evaluate the relationship between degree of visual impairment of patient and his postural stability. The article contains basic explanation and requirements for stabilography research. The paper also describes statistic analysis of influence of visual impairment on postural stability opposed to control group (people perfectly sighted). These results allowed us to verify the approved research plan.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"37 - 54"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/scjme-2016-0017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67003575","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}
Abstract The cable-pulley system is widely used for its advantages. In this paper, application of a new algorithm for the calculation of cables on pulleys is presented. Unlike other algorithms, this algorithm enables to take the magnitude of the radius of each pulley into account. This new algorithm is implemented in the RFEM program because of its higher accuracy and efficiency. Comparison of the commonly used algorithm, which ignores pulley radius, and the new algorithm is presented.
{"title":"A New Cable-Pulley Algorithm in RFEM","authors":"Hynek Štekbauer, I. Němec","doi":"10.1515/scjme-2016-0022","DOIUrl":"https://doi.org/10.1515/scjme-2016-0022","url":null,"abstract":"Abstract The cable-pulley system is widely used for its advantages. In this paper, application of a new algorithm for the calculation of cables on pulleys is presented. Unlike other algorithms, this algorithm enables to take the magnitude of the radius of each pulley into account. This new algorithm is implemented in the RFEM program because of its higher accuracy and efficiency. Comparison of the commonly used algorithm, which ignores pulley radius, and the new algorithm is presented.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"89 - 94"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67003601","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}
Abstract This article deals with a simple planar and statically determinate pin-connected truss. It demonstrates the processes and methods of derivations and solutions according to 1st and 2nd order theories. The article applies linear and nonlinear approaches and their simplifications via a Maclaurin series. Programming connected with the stochastic Simulation-Based Reliability Method (i.e. the direct Monte Carlo approach) is used to conduct a probabilistic reliability assessment (i.e. a calculation of the probability that plastic deformation will occur in members of the truss).
{"title":"Simple Planar Truss (Linear, Nonlinear and Stochastic Approach)","authors":"K. Frydrýšek, R. Janco","doi":"10.1515/scjme-2016-0013","DOIUrl":"https://doi.org/10.1515/scjme-2016-0013","url":null,"abstract":"Abstract This article deals with a simple planar and statically determinate pin-connected truss. It demonstrates the processes and methods of derivations and solutions according to 1st and 2nd order theories. The article applies linear and nonlinear approaches and their simplifications via a Maclaurin series. Programming connected with the stochastic Simulation-Based Reliability Method (i.e. the direct Monte Carlo approach) is used to conduct a probabilistic reliability assessment (i.e. a calculation of the probability that plastic deformation will occur in members of the truss).","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"12 - 5"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67003264","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}
Abstract This paper focuses on the characterization of the tabletting process and analysis one of the most common pharmaceutical excipients MCC Avicel PH102 by Heckel, Kawakita, Cooper-Eaton and Adams compaction equations. Experimental material was determined by measuring its parameters as particle size distribution, angle of wall friction and flow properties and for more detailed characteristics of the material particles, microscopy images of the powder before and after compressing were created.
{"title":"Analysis of Pharmaceutical Excipient MCC Avicel PH102 Using Compaction Equations","authors":"P. Peciar, M. Eckert, Roman Fekete, V. Hrnčiar","doi":"10.1515/scjme-2016-0012","DOIUrl":"https://doi.org/10.1515/scjme-2016-0012","url":null,"abstract":"Abstract This paper focuses on the characterization of the tabletting process and analysis one of the most common pharmaceutical excipients MCC Avicel PH102 by Heckel, Kawakita, Cooper-Eaton and Adams compaction equations. Experimental material was determined by measuring its parameters as particle size distribution, angle of wall friction and flow properties and for more detailed characteristics of the material particles, microscopy images of the powder before and after compressing were created.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"65 - 82"},"PeriodicalIF":0.0,"publicationDate":"2016-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/scjme-2016-0012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67003251","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}
Abstract The article describes the theory of cavitation at high values of shear stress in a viscous liquid. For this purpose, a spatial model of two cylindrical shells imposed concentrically was designed. In the narrow gap between the cylinders the temperature, density and viscosity of liquid is constant. Shear stress is induced by the rotary motion of the inner cylinder, resulting in a change of velocity and pressure fields. Due to the pressure drop between the cylinders there is a precondition to the formation of cavitation bubbles at the point of the lowest static pressure. To verify the assumption was made CFD model based on simplified physical model, through which cavitation was qualitatively and quantitatively assessed. In this paper the results of the numerical solution will be presented alongside with basic form of experimental device for physical generation of cavitation at high values of shear stress.
{"title":"Research of Cavitation at High Shear Stress","authors":"Zoltán Csuka, R. Olšiak, Zoltán Fuszko","doi":"10.1515/scjme-2016-0006","DOIUrl":"https://doi.org/10.1515/scjme-2016-0006","url":null,"abstract":"Abstract The article describes the theory of cavitation at high values of shear stress in a viscous liquid. For this purpose, a spatial model of two cylindrical shells imposed concentrically was designed. In the narrow gap between the cylinders the temperature, density and viscosity of liquid is constant. Shear stress is induced by the rotary motion of the inner cylinder, resulting in a change of velocity and pressure fields. Due to the pressure drop between the cylinders there is a precondition to the formation of cavitation bubbles at the point of the lowest static pressure. To verify the assumption was made CFD model based on simplified physical model, through which cavitation was qualitatively and quantitatively assessed. In this paper the results of the numerical solution will be presented alongside with basic form of experimental device for physical generation of cavitation at high values of shear stress.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"16 - 7"},"PeriodicalIF":0.0,"publicationDate":"2016-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/scjme-2016-0006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67002892","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}
Abstract The main aim of the presented paper is to show how heat treatment, in our case the induction hardening, will affect the wear rates as well as the ratcheting evolution process beneath the contact surface in the field of line rolling contact. Used wear model is based on shear band cracking mechanism [1] and non-linear kinematic and isotropic hardening rule of Chaboche and Lemaitre. The entire numerical simulations have been realized in the C# programming language. Results from numerical simulations are subsequently compared with experimental data.
{"title":"Influence of Induction Hardening on Wear Resistance in Case of Rolling Contact","authors":"M. Šofer, R. Fajkoš, R. Halama","doi":"10.1515/scjme-2016-0007","DOIUrl":"https://doi.org/10.1515/scjme-2016-0007","url":null,"abstract":"Abstract The main aim of the presented paper is to show how heat treatment, in our case the induction hardening, will affect the wear rates as well as the ratcheting evolution process beneath the contact surface in the field of line rolling contact. Used wear model is based on shear band cracking mechanism [1] and non-linear kinematic and isotropic hardening rule of Chaboche and Lemaitre. The entire numerical simulations have been realized in the C# programming language. Results from numerical simulations are subsequently compared with experimental data.","PeriodicalId":35968,"journal":{"name":"Strojnicky Casopis","volume":"66 1","pages":"17 - 26"},"PeriodicalIF":0.0,"publicationDate":"2016-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/scjme-2016-0007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67002997","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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