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Non-iterative wall model formula for non-equilibrium boundary layer flows 非平衡边界层流动的非迭代壁模型公式
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2201223j
A. Jemcov, Joseph Gonzales, J. Maruszewski, Ryan Kelly
{"title":"Non-iterative wall model formula for non-equilibrium boundary layer flows","authors":"A. Jemcov, Joseph Gonzales, J. Maruszewski, Ryan Kelly","doi":"10.5937/fme2201223j","DOIUrl":"https://doi.org/10.5937/fme2201223j","url":null,"abstract":"A novel non-iterative (explicit) formulation of generalized wall functions that applies to equilibrium and non-equilibrium boundary layer flows was proposed. The proposed formulation uses a set of variables that are more useful for computational fluid dynamics codes as they allow for calculating wall shear stress without an iterative procedure. In addition, an explicit form of the formulation was provided that applies to wall models with and without pressure gradients. The new variable transformation casts the generalizedwall function into a new form that simplifies the implementation and evaluation of wall-shear stress in computational codes.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"73 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89226136","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
Fatigue analysis of preloaded bolted joints 预加载螺栓连接的疲劳分析
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2204607w
M. Welch
{"title":"Fatigue analysis of preloaded bolted joints","authors":"M. Welch","doi":"10.5937/fme2204607w","DOIUrl":"https://doi.org/10.5937/fme2204607w","url":null,"abstract":"This article presents Wöhler plots, or S-N curves, for use in the analysis of bolt fatigue of preloaded bolted joints. Preloaded bolts under cyclic loading have a high mean stress with a small alternating stress. This is combined with a large stress concentration at the thread root. The method of fatigue analysis presented uses S-N curves with a zero mean stress. The high mean stress experienced by the bolts is accounted for using a function to calculate a damage-equivalent stress. Notch sensitivity was considered to modify S-N curves for materials with chemical compositions encompassed within the material specifications for high strength bolts. This produced S-N curves for stress concentrations relevant to bolt threads. Curve fitting techniques were used to express these curves as a function of the equivalent stress and stress ratio. An estimate of residual stresses in bolts produced by thread rolling was made. The work provides a practical method of calculating fatigue life.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"100 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89676970","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
Evaluation and multi-criteria optimization of surface roughness, deviation from dimensional accuracy and roundness error in drilling CFRP/Ti6Al4 stacks CFRP/Ti6Al4叠层钻孔表面粗糙度、尺寸精度偏差和圆度误差评价及多准则优化
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2203441m
A. Motorcu, E. Ekici
{"title":"Evaluation and multi-criteria optimization of surface roughness, deviation from dimensional accuracy and roundness error in drilling CFRP/Ti6Al4 stacks","authors":"A. Motorcu, E. Ekici","doi":"10.5937/fme2203441m","DOIUrl":"https://doi.org/10.5937/fme2203441m","url":null,"abstract":"In this study, machinability tests were carried out to investigate the effects of control factors (cutting tool geometry, cutting speed, and feed rate) on the surface roughness (Ra), deviation from dimensional accuracy (Da_dev), roundness error (Re) in drilling CFRP/Ti6Al4V mixed metallic stack and to determine the optimum levels of drilling parameters. The effects of each control factor and their interactions on three quality characteristics were analyzed, and their levels were single-objectively optimized for each component material by the Taguchi method. The material has components (CFRP and Ti6Al4V) with essentially different properties (mechanical, physical, machinability). Single-objective optimization has limited usability as the drilling must be performed in one through both layers. Therefore, in an additional step, the optimum levels of the control factors were determined by optimizing multi-objective with the Additive Ratio Assessment (ARAS) method. Higher Ra, Da_dev, and Re values were obtained on the CFRP component compared to the Ti6Al4V component. The CFRP/Ti6Al4V stack should be drilled with a nano fire coated carbide drill (T3) at medium cutting speed and high feed rate to achieve minimum Ra, Da_dev, and Re values in one go.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"43 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83148827","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
Effect of propane-methanol blending ratio on the stretched and unstretched flame speeds at elevated initial temperatures 初始温度升高时丙烷-甲醇配比对拉伸和非拉伸火焰速度的影响
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2201121a
A. Abdulraheem, Adel A. M. Saleh, H. Shahad
{"title":"Effect of propane-methanol blending ratio on the stretched and unstretched flame speeds at elevated initial temperatures","authors":"A. Abdulraheem, Adel A. M. Saleh, H. Shahad","doi":"10.5937/fme2201121a","DOIUrl":"https://doi.org/10.5937/fme2201121a","url":null,"abstract":"The unstretched flame speed of the premixed propane-methanol/ air flames has been studied experimentally in a constant volume combustion chamber with central ignition. The experiments were done at atmospheric pressure and stoichiometric air/fuel ratio. Various blending ratios of methanol (0%, 20%, 40%, 60%, 80%, 100%) by volume, and different elevated initial temperatures (348 K, 373 K, and 398 K) were used in this study. In general, the results indicated that the unstretched flame speed increased with increasing both methanol blending ratio and initial temperature. For M60 the increment value of unstretched flame speed at Ti=398K was about 9% compared with that of pure propane and by elevating the initial temperature for the same blend ratio (M60) from 348 K to 398 K the increment value was about 8.8%. It is also noticed that Markstein length decreased with increasing both initial temperature and blending ratio, which is indicate that flame instability increased with increasing these parameters.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"31 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78233124","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: 1
Experimental investigation of the friction modifying effects of different nanoforms of graphene additives in engine lubricating oil 不同纳米形式石墨烯添加剂对发动机润滑油摩擦改性效果的实验研究
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2201248t
C. Tóth-Nagy, A. Szabó
{"title":"Experimental investigation of the friction modifying effects of different nanoforms of graphene additives in engine lubricating oil","authors":"C. Tóth-Nagy, A. Szabó","doi":"10.5937/fme2201248t","DOIUrl":"https://doi.org/10.5937/fme2201248t","url":null,"abstract":"This article presents the results of an experimental investigation of different nanoforms of graphene used as a nano additive in engine lubricating oil. The experiments were carried out on a pin-on-disc tribometer at the Department of Internal Combustion Engines and Propulsions at Széchenyi István University. The paper introduces the experimental equipment and the experimental method and presents the research findings. The paper concludes that fullerene can decrease friction by 7% on average when used as a nano additive in engine lubricating oil. Furthermore, fullerene did not present a sedimentation problem when used as an additive up to 0.25 wt% in lubricant instead of graphene and multiwalled carbon nanotubes. The paper attempts to explain the friction decreasing effect and the possible roles of carbon nano additives in tribological systems.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"196 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77427663","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: 1
Investigation of coefficient of friction at the interface of automobile brake pads using Greenwood-Williamson contact model and novel test rig 基于Greenwood-Williamson接触模型和新型试验台的汽车刹车片接触面摩擦系数研究
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2203561k
Mrunal P. Kshirsagar, H. Khairnar
{"title":"Investigation of coefficient of friction at the interface of automobile brake pads using Greenwood-Williamson contact model and novel test rig","authors":"Mrunal P. Kshirsagar, H. Khairnar","doi":"10.5937/fme2203561k","DOIUrl":"https://doi.org/10.5937/fme2203561k","url":null,"abstract":"Different brake pad materials are produced, each with their unique composition in the recent past, yet performing the same task and claiming to be better than others. The article provides references for different automotive brake pads subjected to various operating conditions. The present investigation develops an analytical approach for estimating COF and contact radius for different disc-brake pads, which can be used to design an efficient automotive brake pad-disc system under the given load and rotational speed. The coefficient of friction at the pad-disc interface is investigated considering Greenwood Williamson (GW) model and developed novel friction test rig. A MATLAB program along with FFT was developed to simulate the surface topography of the contact interface during the braking process aiding the estimation of contact radius. Surface topography of tested brake pads has been analyzed using an infinite-focus-microscope to verify contact radius. At last, the reference is verified by an experimental investigation using a developed test rig and considering operating parameters.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"39 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80911641","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
The development of methodological techniques and an algorithm for diagnosing modern intake systems for internal combustion engines 现代内燃机进气系统诊断方法技术和算法的发展
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2201302b
A. Balyasnikov, A. Gritsenko, V. Shepelev, B. Kaliyev, N. Kostyuchenkov, O. Fadina
{"title":"The development of methodological techniques and an algorithm for diagnosing modern intake systems for internal combustion engines","authors":"A. Balyasnikov, A. Gritsenko, V. Shepelev, B. Kaliyev, N. Kostyuchenkov, O. Fadina","doi":"10.5937/fme2201302b","DOIUrl":"https://doi.org/10.5937/fme2201302b","url":null,"abstract":"Type Diagnosing and detecting malfunctions in internal combustion engines (ICE) is not an easy task due to their complex design. Timely and high-quality ICE monitoring allows performance to be maintained and prevents breakdowns. Vibration and acoustic analysis is a powerful and informative tool for detecting faults even at an early stage. This article considers a method for determining the main malfunctions of the valvetrain (VT) (tightness of the \"valve-seat\" interface, thermal gap in the valve drive, valve opening and closing phases) by measuring and analyzing vibroacoustic pulses caused by the operation of individual engine elements. The maximum amplitude and the moment of vibration impulses are used as signal parameters. For the reference signal of the piston, the top dead center (TDC) of the cylinder under study, a vibration pulse from the impact of the piston on an elastic tip placed in the combustion chamber is taken. This technique makes it possible to exclude the external influences and inaccuracies associated with a change in the geometry ICE elements.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"10 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90277685","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
Influence of gender, education, age group and time in the company on the adoption of new technologies and their impact on continuous Improvement 公司性别、教育程度、年龄和时间对新技术采用的影响及其对持续改进的影响
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2204635d
J. Dinis-Carvalho, Mónica F. J. R. Monteiro, Helena Macedo
{"title":"Influence of gender, education, age group and time in the company on the adoption of new technologies and their impact on continuous Improvement","authors":"J. Dinis-Carvalho, Mónica F. J. R. Monteiro, Helena Macedo","doi":"10.5937/fme2204635d","DOIUrl":"https://doi.org/10.5937/fme2204635d","url":null,"abstract":"Continuous Improvement (CI) is a principle being adopted in many organizations around the world. It is present in relevant excellence models such as the Toyota Way, Shingo Model, and Lean Thinking. CI was implemented some years ago in a Public Company (Lipor) based in Porto, dedicated to municipal waste treatment, but the Covid-19 pandemic created some important challenges. The forced adoption of new technologies associated with I4.0 required important changes in the existing CI routines. This paper aims to assess the influence of gender, education, age group, and time in the company on adopting new technologies used in their IC routines. This study, based on employees' perceptions through questionnaires, shows that the CI system had, in general, a positive impact on their work and overall performance. Regarding the effect of forced teleworking caused by COVID-19 on office workers, this study shows that age, gender, education, and years in the company have an impact on the effective adoption of new technologies associated with digital transformation and Industry 4.0. The study also shows that those technologies effectively allow routines and culture of CI to be maintained when workers are forced to work remotely.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"90 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83925163","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: 1
Design, simulation and experiment of PSO-FOPID controller for height position control of a scissor mechanism platform 剪刀机构平台高度位置控制的PSO-FOPID控制器的设计、仿真与实验
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2201046n
N. Norsahperi, S. Ahmad, S. Toha, M. Mutalib
{"title":"Design, simulation and experiment of PSO-FOPID controller for height position control of a scissor mechanism platform","authors":"N. Norsahperi, S. Ahmad, S. Toha, M. Mutalib","doi":"10.5937/fme2201046n","DOIUrl":"https://doi.org/10.5937/fme2201046n","url":null,"abstract":"This paper proposes the PSO-FOPID controller, which is a Fractional Order Proportional-Integral-Derivative (FOPID) controller tuned using particle swarm optimization with spreading factor algorithm for height position control of a scissor mechanism platform. The tuning process of five control gains in the FOPID controller is technically challenging to achieve high position accuracy. In this study, this problem is addressed through the offline tuning method by using particle swarm optimization with the spreading factor algorithm to reduce the complexity in tuning the control gains. From the experimental study, it is found that the proposed controller can eliminate the steady-state error under the two input references with approximately 1.5% and 0.9% reductions of the overshoot and undershoot in the height position response as compared to its promising performances in simulations. It is envisaged that the PSOFOPID controller can be useful in designing effective height position control of a non-linear platform.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"31 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88941045","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
Fuzzy controller optimized by the African vultures algorithm for trajectory tracking of a two-link gripping mechanism 非洲秃鹫算法优化的模糊控制器用于双连杆夹持机构的轨迹跟踪
IF 1.6
FME Transactions Pub Date : 2022-01-01 DOI: 10.5937/fme2203491j
Radisa Z. Jovanovic, U. Bugaric, Mitra Vesović, Natalija Perišić
{"title":"Fuzzy controller optimized by the African vultures algorithm for trajectory tracking of a two-link gripping mechanism","authors":"Radisa Z. Jovanovic, U. Bugaric, Mitra Vesović, Natalija Perišić","doi":"10.5937/fme2203491j","DOIUrl":"https://doi.org/10.5937/fme2203491j","url":null,"abstract":"This paper presents the proportional-derivative fuzzy controller for trajectory tracking of the gripping mechanism with two degrees of freedom. Aiming to achieve movement of the gripping mechanism without sudden starting and stopping, a polynomial velocity profile is utilized. The African vultures optimization, as one of the latest metaheuristic algorithms, is used to obtain the optimal input/output scaling gains of the proposed fuzzy controller according to the selected fitness function. The results obtained by this algorithm are compared with the other three new and popular metaheuristic algorithms: the whale optimization, the ant lion optimization and the sine cosine algorithm. Moreover, a simulation study was done for the defined initial position and for the scenario where there is a certain deviation because the gripping mechanism is not at its original initial position. Finally, the robustness of the controller is tested for the case when the masses of the segments increase three times. The results revealed that the suggested controller was capable of dealing with nonlinearities of the gripping mechanism, initial position and parameter changes. The movement of the gripping mechanism is smooth and follows the defined trajectory.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":"22 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88497413","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
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