Abstract Rear wind is the air flow that blows in the rear side of the truck. Also known as a tailwind, this aerodynamic force can cause stability issues during forward travel. The methodology of the study is CFD numerical analysis of vehicle aerodynamics. The results will be acquired for the influential aerodynamic parameters, which includes velocity, pressure, vortex, stress, that will explain the impact of rear wind on the truck body. This is achieved with the aid of design, modelling, and simulations using software Comsol Multiphysics. The simulations were performed with freestream velocity of rear wind on the back and around the truck body. Virtual Wind tunnel is modelled around the truck to simulate the wind blow and distribution. There are two airflow regimes analysed: laminar flow and turbulent flow. Simulations for the laminar air flow were implemented for Compressed air flow and the velocity limit Ma<0.3. Simulations for the turbulent air flow regime were implemented based on Reynolds-Averaged Navier-Stokes Equations (RANS) and K-ω model. Anemometer device is used for the experimental measurements of the wind velocity around the truck. The wind is a function of air velocity and atmospheric pressure. The paper is in the fields of Vehicle aerodynamics, Fluid Mechanics, and Transport safety.
后风是吹在卡车后部的气流。也被称为顺风，这种空气动力会导致前进过程中的稳定性问题。研究方法为CFD车辆空气动力学数值分析。将获得影响气动参数的结果，包括速度、压力、涡、应力，这些参数将解释后风对卡车车身的影响。这是通过使用软件Comsol Multiphysics的设计、建模和仿真来实现的。模拟时考虑了卡车后部和车身周围风的自由流速度。在卡车周围建立虚拟风洞，模拟风的吹动和分布。分析了两种气流形式:层流和湍流。对压缩空气流和速度极限Ma<0.3进行层流模拟。基于reynolds - average Navier-Stokes方程组(RANS)和K-ω模型对湍流气流进行了模拟。风速计装置用于试验测量卡车周围的风速。风是空气速度和大气压力的函数。论文涉及车辆空气动力学、流体力学和运输安全。
{"title":"Numerical Analysis of the Rear Wind Influence on the Truck During Travel","authors":"I. Doçi, F. Shala","doi":"10.2478/scjme-2022-0015","DOIUrl":"https://doi.org/10.2478/scjme-2022-0015","url":null,"abstract":"Abstract Rear wind is the air flow that blows in the rear side of the truck. Also known as a tailwind, this aerodynamic force can cause stability issues during forward travel. The methodology of the study is CFD numerical analysis of vehicle aerodynamics. The results will be acquired for the influential aerodynamic parameters, which includes velocity, pressure, vortex, stress, that will explain the impact of rear wind on the truck body. This is achieved with the aid of design, modelling, and simulations using software Comsol Multiphysics. The simulations were performed with freestream velocity of rear wind on the back and around the truck body. Virtual Wind tunnel is modelled around the truck to simulate the wind blow and distribution. There are two airflow regimes analysed: laminar flow and turbulent flow. Simulations for the laminar air flow were implemented for Compressed air flow and the velocity limit Ma<0.3. Simulations for the turbulent air flow regime were implemented based on Reynolds-Averaged Navier-Stokes Equations (RANS) and K-ω model. Anemometer device is used for the experimental measurements of the wind velocity around the truck. The wind is a function of air velocity and atmospheric pressure. The paper is in the fields of Vehicle aerodynamics, Fluid Mechanics, and Transport safety.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128047677","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}
Lukáš Pacoň, O. Vitek, Vít Doleček, J. Macek, Jindřich Hořenín
Abstract This paper describes a possible approach of designing an unconventional turbocharger using co-simulation method. Our goal is to design turbochargers running optimally during pulsating and transient modes. It means to develop a tool capable of co-simulation between 3-D and 1-D CFD. This tool must be fast and precise enough and provide a reliable result. Influence of a coarse mesh versus fine mesh was examined. Different time step size was applied to determine calculation sensitivity. Different types of turbines were tested.
{"title":"Prediction of Pulsating Turbine Operation Using 1-D - 3-D Co-Simulation","authors":"Lukáš Pacoň, O. Vitek, Vít Doleček, J. Macek, Jindřich Hořenín","doi":"10.2478/scjme-2022-0043","DOIUrl":"https://doi.org/10.2478/scjme-2022-0043","url":null,"abstract":"Abstract This paper describes a possible approach of designing an unconventional turbocharger using co-simulation method. Our goal is to design turbochargers running optimally during pulsating and transient modes. It means to develop a tool capable of co-simulation between 3-D and 1-D CFD. This tool must be fast and precise enough and provide a reliable result. Influence of a coarse mesh versus fine mesh was examined. Different time step size was applied to determine calculation sensitivity. Different types of turbines were tested.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125657953","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 a diagnostic method, on the basis of which it is possible to assess whether there is a loose connection in the clamping system (detection) and to determine which of them is loose (localization). The diagnostic method is based on comparing the drops in the natural frequencies of a measured system with respect to a reference system, which simulates the desired state. When analysing the drop in natural frequencies in order to locate the loosening, it is necessary to relate this drop to the position of the clamping joints within the considered mode shape.
{"title":"Diagnostics of a Clamping Joint System","authors":"M. Musil, J. Úradníček, Marek Páleník, O. Chlebo","doi":"10.2478/scjme-2022-0022","DOIUrl":"https://doi.org/10.2478/scjme-2022-0022","url":null,"abstract":"Abstract The article describes a diagnostic method, on the basis of which it is possible to assess whether there is a loose connection in the clamping system (detection) and to determine which of them is loose (localization). The diagnostic method is based on comparing the drops in the natural frequencies of a measured system with respect to a reference system, which simulates the desired state. When analysing the drop in natural frequencies in order to locate the loosening, it is necessary to relate this drop to the position of the clamping joints within the considered mode shape.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133068901","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 describes the testing of oil filters on a laboratory test device designed to monitor changes in oil filter flow and pressure, depending on the level of engine oil contamination. The laboratory test device enables testing the suitability of using filters with different filtering capabilities, even with differently polluted engine oil. The measurement results can be used in the design of new filter materials, or in the design of changing replacement intervals, which would mean a benefit from an economic as well as an ecological point of view.
{"title":"Test of Oil Filters on Laboratory Test Device","authors":"L. Hujo, J. Kaszkowiak, J. Nosian, M. Michalides","doi":"10.2478/scjme-2022-0037","DOIUrl":"https://doi.org/10.2478/scjme-2022-0037","url":null,"abstract":"Abstract This article describes the testing of oil filters on a laboratory test device designed to monitor changes in oil filter flow and pressure, depending on the level of engine oil contamination. The laboratory test device enables testing the suitability of using filters with different filtering capabilities, even with differently polluted engine oil. The measurement results can be used in the design of new filter materials, or in the design of changing replacement intervals, which would mean a benefit from an economic as well as an ecological point of view.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117253741","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 Based on its superior casting and mechanical properties, LM26 is a well-known material in the automobile sector for the manufacturing of pistons for both diesel and gasoline engines. However, cast alloys diminishing the strength at higher temperatures leads to metal matrix composites. The present work deals with fabrication and characterisation of aluminium cast alloy LM26 reinforced with ceramic particles of Almandine Garnet with varying percentages fabricated by dual step stir casting technique The micro hardness and ultimate tensile strength (UTS) were determined and the sliding wear behaviour was estimated using a pin-on-disc apparatus. The effect of particle size and weight fraction of reinforcement on physical and mechanical properties were investigated and collated with unreinforced metal. Wear behaviour of the composite had a reasonably good correlation with composite mechanical properties were also observed. Validation of Experimental results with theoretical values were also discussed.
{"title":"Evaluation of Wear Behaviour Based on Mechanical Properties and Particle Size in LM26 MMC","authors":"Lakshmi Chaitanya Konda, K. Srinivas","doi":"10.2478/scjme-2022-0019","DOIUrl":"https://doi.org/10.2478/scjme-2022-0019","url":null,"abstract":"Abstract Based on its superior casting and mechanical properties, LM26 is a well-known material in the automobile sector for the manufacturing of pistons for both diesel and gasoline engines. However, cast alloys diminishing the strength at higher temperatures leads to metal matrix composites. The present work deals with fabrication and characterisation of aluminium cast alloy LM26 reinforced with ceramic particles of Almandine Garnet with varying percentages fabricated by dual step stir casting technique The micro hardness and ultimate tensile strength (UTS) were determined and the sliding wear behaviour was estimated using a pin-on-disc apparatus. The effect of particle size and weight fraction of reinforcement on physical and mechanical properties were investigated and collated with unreinforced metal. Wear behaviour of the composite had a reasonably good correlation with composite mechanical properties were also observed. Validation of Experimental results with theoretical values were also discussed.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"5 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131359073","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}
Štěpán Pícha, M. Kotek, V. Hartová, Veronika Štekerová
Abstract Electric vehicles are growing in popularity and are reviving a much disused powertrain in the vehicle sector. This paper deals with the measurement of driving performance of electric vehicles. For twelve selected vehicles, the parameters given by the vehicle manufacturer and measured during individual runs were compared. The measurements were carried out on a predetermined route, divided into several parts. The data obtained here not only serve to compare the parameters, but also to determine the degree of dependence of the individual measured parameters on the range of the vehicles.
{"title":"Measuring the Operating Parameters of Electric Vehicles","authors":"Štěpán Pícha, M. Kotek, V. Hartová, Veronika Štekerová","doi":"10.2478/scjme-2022-0045","DOIUrl":"https://doi.org/10.2478/scjme-2022-0045","url":null,"abstract":"Abstract Electric vehicles are growing in popularity and are reviving a much disused powertrain in the vehicle sector. This paper deals with the measurement of driving performance of electric vehicles. For twelve selected vehicles, the parameters given by the vehicle manufacturer and measured during individual runs were compared. The measurements were carried out on a predetermined route, divided into several parts. The data obtained here not only serve to compare the parameters, but also to determine the degree of dependence of the individual measured parameters on the range of the vehicles.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125892574","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}
O. Ustynenko, Oleksij Bondarenko, I. Klochkov, R. Protasov, M. Bošanský, Sergij Andrienko
Abstract Solving the problem of optimization for transmission load-carrier/prime mover MT-LB improves the mass characteristics of the machine. Mathematical model of optimization was constructed, namely: optimization objective function was built; variables planning are defined; a system of constraints was constructed. The solution is based on probing the parameter space, where points of the LPτ-sequence are used as test points in a single multidimensional cube. Also, the algorithm for optimal design of the transmission has been developed.
{"title":"Mathematical Model and Optimization Algorithm By Mass of Tracked Load-Carrier/Prime Mover MT-LB Transmission","authors":"O. Ustynenko, Oleksij Bondarenko, I. Klochkov, R. Protasov, M. Bošanský, Sergij Andrienko","doi":"10.2478/scjme-2022-0012","DOIUrl":"https://doi.org/10.2478/scjme-2022-0012","url":null,"abstract":"Abstract Solving the problem of optimization for transmission load-carrier/prime mover MT-LB improves the mass characteristics of the machine. Mathematical model of optimization was constructed, namely: optimization objective function was built; variables planning are defined; a system of constraints was constructed. The solution is based on probing the parameter space, where points of the LPτ-sequence are used as test points in a single multidimensional cube. Also, the algorithm for optimal design of the transmission has been developed.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125203723","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 An analytical method for determination of a stress condition of butt welded thin-gauge plates with asymmetrical reinforcement is developed. The proposed method allows take into account the effect of the load application eccentricity on the tensile stress concentration factor (SCF) in the weld root zone. It is presented that the bending stresses, caused by this eccentricity, result in increasing the total stresses up to 75%. The results of analytical SCF calculations are in good agreement with the results obtained using the finite element method.
{"title":"Effect of Load Eccentricity on Stress Condition of Butt Welded Joint with Asymmetrical Reinforcement","authors":"A. Moltasov, P. Tkach, O. Ustynenko, R. Protasov","doi":"10.2478/scjme-2022-0010","DOIUrl":"https://doi.org/10.2478/scjme-2022-0010","url":null,"abstract":"Abstract An analytical method for determination of a stress condition of butt welded thin-gauge plates with asymmetrical reinforcement is developed. The proposed method allows take into account the effect of the load application eccentricity on the tensile stress concentration factor (SCF) in the weld root zone. It is presented that the bending stresses, caused by this eccentricity, result in increasing the total stresses up to 75%. The results of analytical SCF calculations are in good agreement with the results obtained using the finite element method.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133400053","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}
Adam Guštafík, Kristian Jezso, Karolína Vaľková, O. Macho, P. Peciar
Abstract This paper focuses on the effect of moisture of powder material on the process of tablet compression and on tablet mechanical strength. The powder used in the experiments was Avicel PH102 microcrystalline cellulose, as it is the most widely used excipient in direct tablet compression. The compression process is described using the Heckel equation and the strength of the tablets was determined using a Brazilian test. To introduce the reader to the issue, the first part of the paper is devoted to a theoretical introduction. The second part of the work is devoted to the description of experimental equipment and work procedure. The last part of the paper presents the results of the experiment and their evaluation. The reason for this experiment was the assumption that the moisture of the raw material significantly affects the compression process and the mechanical strength of the tablet. A series of experiments demonstrated this effect, which can be seen in the respective graphs.
{"title":"Effect of Moisture of Pharmaceutical Material MCC Avicel PH102 and Tablet Diameter on the Compression Process and Tablet Strength","authors":"Adam Guštafík, Kristian Jezso, Karolína Vaľková, O. Macho, P. Peciar","doi":"10.2478/scjme-2022-0005","DOIUrl":"https://doi.org/10.2478/scjme-2022-0005","url":null,"abstract":"Abstract This paper focuses on the effect of moisture of powder material on the process of tablet compression and on tablet mechanical strength. The powder used in the experiments was Avicel PH102 microcrystalline cellulose, as it is the most widely used excipient in direct tablet compression. The compression process is described using the Heckel equation and the strength of the tablets was determined using a Brazilian test. To introduce the reader to the issue, the first part of the paper is devoted to a theoretical introduction. The second part of the work is devoted to the description of experimental equipment and work procedure. The last part of the paper presents the results of the experiment and their evaluation. The reason for this experiment was the assumption that the moisture of the raw material significantly affects the compression process and the mechanical strength of the tablet. A series of experiments demonstrated this effect, which can be seen in the respective graphs.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114272284","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 Sieving or screening plays a crucial role in the processing of particulate materials. The sieving process is affected by many factors, including the selection of suitable sieving equipment. Several experiments were carried out to examine the influence of three basic sieving parameters on process efficiency. The investigated material was MCC Avicel PH102, which is widely used as an excipient in the pharmaceutical industry. The three mentioned parameters were sample mass, sieving duration, and vibration amplitude. It was necessary to find a suitable method to evaluate screening efficiency.
{"title":"Influence of the Selected Sieving Parameters on the Sieving Efficiency of Material MCC Avicel PH102","authors":"Kristian Jezso, P. Peciar","doi":"10.2478/scjme-2022-0008","DOIUrl":"https://doi.org/10.2478/scjme-2022-0008","url":null,"abstract":"Abstract Sieving or screening plays a crucial role in the processing of particulate materials. The sieving process is affected by many factors, including the selection of suitable sieving equipment. Several experiments were carried out to examine the influence of three basic sieving parameters on process efficiency. The investigated material was MCC Avicel PH102, which is widely used as an excipient in the pharmaceutical industry. The three mentioned parameters were sample mass, sieving duration, and vibration amplitude. It was necessary to find a suitable method to evaluate screening efficiency.","PeriodicalId":445896,"journal":{"name":"Strojnícky časopis - Journal of Mechanical Engineering","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133036985","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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