Pub Date : 2024-07-31DOI: 10.1177/16878132241266757
Dong Ma, Zhihao Liu, Qinhe Gao, Lei Gao
By analyzing the deficiencies of existing hydraulic erecting systems (HESs) control methods, this study proposes a linear time-varying model predictive control (LTV-MPC) method based on the linear extended state observer (LESO) for HESs. First, the working mechanism of HESs is methodically analyzed and the corresponding state space equations are established. Second, the LESO system is designed to estimate the current unknown real-time states. Then, the LTV-MPC is employed to evaluate and output the optimal solution of the servo voltage signal. Finally, through simulation and experiment, the effectiveness of the proposed method is confirmed and discussed. The results show that the displacement error rate of the proposed method is still lower than 0.223% under larger external disturbances, which can effectively improve the control accuracy and stability of the system compared with other methods.
{"title":"Predictive control of linear time-varying model for hydraulic erecting systems based on linear expanded state observer","authors":"Dong Ma, Zhihao Liu, Qinhe Gao, Lei Gao","doi":"10.1177/16878132241266757","DOIUrl":"https://doi.org/10.1177/16878132241266757","url":null,"abstract":"By analyzing the deficiencies of existing hydraulic erecting systems (HESs) control methods, this study proposes a linear time-varying model predictive control (LTV-MPC) method based on the linear extended state observer (LESO) for HESs. First, the working mechanism of HESs is methodically analyzed and the corresponding state space equations are established. Second, the LESO system is designed to estimate the current unknown real-time states. Then, the LTV-MPC is employed to evaluate and output the optimal solution of the servo voltage signal. Finally, through simulation and experiment, the effectiveness of the proposed method is confirmed and discussed. The results show that the displacement error rate of the proposed method is still lower than 0.223% under larger external disturbances, which can effectively improve the control accuracy and stability of the system compared with other methods.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"163 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many machine learning (ML) algorithms have been developed over the past two decades for prognostics and health management (PHM) of complex engineering systems. However, most of the existing algorithms tend to produce point estimates of a variable of interest, for example the equipment’s remaining useful life (RUL). The point estimation of the RUL often neglects the uncertainty inherent in model parameters and/or the uncertainty associated with data inputs. Bayesian Neural Networks (BNNs) have shown a lot of promise in obtaining credible intervals for model parameters, thus accounting for the uncertainties inherent in both the model and data. This paper proposes a deep BNN model with the Monte Carlo (MC) dropout method to predict the RUL of engineering systems equipped with sensors and monitoring instruments. The model is tested on NASA’s Turbofan Engine Degradation Simulation Dataset and the results are discussed and analyzed. It is revealed that the method can produce highly accurate predictions for RUL distribution parameters in safety critical components.
过去二十年来，针对复杂工程系统的预报和健康管理（PHM）开发了许多机器学习（ML）算法。然而，大多数现有算法都倾向于对相关变量（例如设备的剩余使用寿命 (RUL)）进行点估算。RUL 的点估计往往会忽略模型参数固有的不确定性和/或与数据输入相关的不确定性。贝叶斯神经网络（BNN）在获得模型参数可信区间方面显示出了巨大的潜力，从而考虑到了模型和数据中固有的不确定性。本文提出了一种深度 BNN 模型，该模型采用蒙特卡罗（MC）剔除法，用于预测配备传感器和监测仪器的工程系统的 RUL。该模型在 NASA 的涡扇发动机退化模拟数据集上进行了测试，并对结果进行了讨论和分析。结果表明，该方法可对安全关键部件的 RUL 分布参数进行高精度预测。
{"title":"Bayesian neural networks for uncertainty quantification in remaining useful life prediction of systems with sensor monitoring","authors":"Sunday Ochella, Fateme Dinmohammadi, Mahmood Shafiee","doi":"10.1177/16878132241239802","DOIUrl":"https://doi.org/10.1177/16878132241239802","url":null,"abstract":"Many machine learning (ML) algorithms have been developed over the past two decades for prognostics and health management (PHM) of complex engineering systems. However, most of the existing algorithms tend to produce point estimates of a variable of interest, for example the equipment’s remaining useful life (RUL). The point estimation of the RUL often neglects the uncertainty inherent in model parameters and/or the uncertainty associated with data inputs. Bayesian Neural Networks (BNNs) have shown a lot of promise in obtaining credible intervals for model parameters, thus accounting for the uncertainties inherent in both the model and data. This paper proposes a deep BNN model with the Monte Carlo (MC) dropout method to predict the RUL of engineering systems equipped with sensors and monitoring instruments. The model is tested on NASA’s Turbofan Engine Degradation Simulation Dataset and the results are discussed and analyzed. It is revealed that the method can produce highly accurate predictions for RUL distribution parameters in safety critical components.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"45 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The vehicle acceleration process is often accompanied by torsional vibration of the powertrain system. Poor torsional vibration performance significantly influences the driving comfort of the vehicle and the reliability of powertrain components. Compared to passenger cars, commercial vehicles, especially the heavy-duty truck, exhibit more complicated vibration behaviors during acceleration due to the multiple power branches, various gears, and different working conditions. This article presents systematic research on the modeling method, vibration characteristics, mechanism, and influence factors of the torsional resonance of the heavy-duty vehicle during acceleration. A 16-DOF powertrain model considering multiple nonlinearities of the system is proposed and experimentally validated reliable. Numerical and experimental studies are carried out to investigate the vibration characteristics and mechanism of the heavy-duty vehicle powertrain, and the modal energies and parameter influences are also discussed. Besides, an optimization example is presented to analyze the potential vibration attenuation performance of optimizing the clutch parameters. The results indicate that the overall powertrain mode of the heavy-duty vehicle tends to be aroused by the engine firing frequency during accelerating, inducing violent speed fluctuations of the powertrain components between the clutch and half-shafts. The clutch parameters have significant impacts on the powertrain resonance, and the vibration amplitude of the powertrain system can be effectively attenuated to acceptable levels by optimally designing the clutch parameters.
{"title":"Nonlinear modeling and torsional vibration analysis of heavy-duty vehicle powertrain system during acceleration","authors":"Junlong Qu, Wenku Shi, Zhiyong Chen, Renfei Yuan, Jian Liu, Yanyan Zhao, Niancheng Guo","doi":"10.1177/16878132241263936","DOIUrl":"https://doi.org/10.1177/16878132241263936","url":null,"abstract":"The vehicle acceleration process is often accompanied by torsional vibration of the powertrain system. Poor torsional vibration performance significantly influences the driving comfort of the vehicle and the reliability of powertrain components. Compared to passenger cars, commercial vehicles, especially the heavy-duty truck, exhibit more complicated vibration behaviors during acceleration due to the multiple power branches, various gears, and different working conditions. This article presents systematic research on the modeling method, vibration characteristics, mechanism, and influence factors of the torsional resonance of the heavy-duty vehicle during acceleration. A 16-DOF powertrain model considering multiple nonlinearities of the system is proposed and experimentally validated reliable. Numerical and experimental studies are carried out to investigate the vibration characteristics and mechanism of the heavy-duty vehicle powertrain, and the modal energies and parameter influences are also discussed. Besides, an optimization example is presented to analyze the potential vibration attenuation performance of optimizing the clutch parameters. The results indicate that the overall powertrain mode of the heavy-duty vehicle tends to be aroused by the engine firing frequency during accelerating, inducing violent speed fluctuations of the powertrain components between the clutch and half-shafts. The clutch parameters have significant impacts on the powertrain resonance, and the vibration amplitude of the powertrain system can be effectively attenuated to acceptable levels by optimally designing the clutch parameters.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"46 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-26DOI: 10.1177/16878132241266457
Lixiong Gu, Jieming Hong, Niujing Ma
This article examines residual stress generation in U-ribbed steel bridge deck during welding, focusing on post-welding changes in the base material’s residual stress pattern. A thermo-elasto-plastic finite element analysis model was established to conduct numerical simulations of the welding process, summarizing the residual stress changes near the weld seam, the conclusion was drawn that the tensile and compressive forms of transverse residual stress on the upper and lower surfaces of the base plate were inconsistent. To validate the proposed numerical simulation method’s accuracy, the blind hole method was employed to measure welding-induced residual stress, and finite element analysis calculated calibration coefficients A and B, demonstrating the method’s effectiveness. Comparison of experimental measurements with numerical simulation outcomes validate the finite element simulation method’s accuracy and the adopted methodology’s feasibility. Based on these findings, a piecewise linear fitting approach was adopted to develop a simplified model of welding residual stress. The simplified model provides the initial conditions of residual stress for mechanical calculation of U-rib of the same type.
本文研究了 U 型肋钢桥面在焊接过程中产生的残余应力，重点关注焊接后母材残余应力形态的变化。文章建立了热-弹塑性有限元分析模型，对焊接过程进行了数值模拟，总结了焊缝附近的残余应力变化，得出了底板上下表面横向残余应力的拉伸和压缩形式不一致的结论。为了验证所提出的数值模拟方法的准确性，采用了盲孔法测量焊接引起的残余应力，并通过有限元分析计算出了校准系数 A 和 B，证明了该方法的有效性。实验测量结果与数值模拟结果的比较验证了有限元模拟方法的准确性和所采用方法的可行性。在此基础上，采用分片线性拟合方法建立了焊接残余应力简化模型。简化模型为同类 U 形肋的机械计算提供了残余应力的初始条件。
{"title":"Analysis and simplified model calculation of residual stress in U-rib welding of steel bridge deck","authors":"Lixiong Gu, Jieming Hong, Niujing Ma","doi":"10.1177/16878132241266457","DOIUrl":"https://doi.org/10.1177/16878132241266457","url":null,"abstract":"This article examines residual stress generation in U-ribbed steel bridge deck during welding, focusing on post-welding changes in the base material’s residual stress pattern. A thermo-elasto-plastic finite element analysis model was established to conduct numerical simulations of the welding process, summarizing the residual stress changes near the weld seam, the conclusion was drawn that the tensile and compressive forms of transverse residual stress on the upper and lower surfaces of the base plate were inconsistent. To validate the proposed numerical simulation method’s accuracy, the blind hole method was employed to measure welding-induced residual stress, and finite element analysis calculated calibration coefficients A and B, demonstrating the method’s effectiveness. Comparison of experimental measurements with numerical simulation outcomes validate the finite element simulation method’s accuracy and the adopted methodology’s feasibility. Based on these findings, a piecewise linear fitting approach was adopted to develop a simplified model of welding residual stress. The simplified model provides the initial conditions of residual stress for mechanical calculation of U-rib of the same type.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"424 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-26DOI: 10.1177/16878132241266751
Zou Shuaidong, Xie Guanghui, Yang Renqiang, Hou Jingming, Sun Fanwei
In this study, a zero-spin cone-roller traction drive (CRTD) is presented for the joints transmission system in rehabilitation robots due to its high transmission performance and characteristics of overload protection. It can achieve safe interactions among humans, rehabilitation robots, and the environment, making it a potential substitute for traditional gear-based transmission systems. The performance of CRTD, especially efficiency, is studied in this paper based on an elastohydrodynamic lubrication (EHL) model with the considerations of the non-Newtonian effect. The results demonstrate that the overall efficiency differs in different stages, reaching a maximum value of 95%. The overload protection activates when there is a sharp drop in efficiency, and the overload threshold can be identified by the efficiency, which may provide guidance for operation and optimization.
{"title":"Rehabilitation robot joint performance evaluation of a zero-spin traction drive with non-Newtonian fluid considered","authors":"Zou Shuaidong, Xie Guanghui, Yang Renqiang, Hou Jingming, Sun Fanwei","doi":"10.1177/16878132241266751","DOIUrl":"https://doi.org/10.1177/16878132241266751","url":null,"abstract":"In this study, a zero-spin cone-roller traction drive (CRTD) is presented for the joints transmission system in rehabilitation robots due to its high transmission performance and characteristics of overload protection. It can achieve safe interactions among humans, rehabilitation robots, and the environment, making it a potential substitute for traditional gear-based transmission systems. The performance of CRTD, especially efficiency, is studied in this paper based on an elastohydrodynamic lubrication (EHL) model with the considerations of the non-Newtonian effect. The results demonstrate that the overall efficiency differs in different stages, reaching a maximum value of 95%. The overload protection activates when there is a sharp drop in efficiency, and the overload threshold can be identified by the efficiency, which may provide guidance for operation and optimization.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"7 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The droplet collision phenomenon is a more complex heat and mass transfer phase transition phenomenon, which is subject to the joint action of kinetics and thermodynamics. During the collision process, the mutual fusion interference of double droplets makes the kinetic mechanism after droplet collision more complicated, and its in-depth study can provide important theoretical support for the fields of engineering applications, industrial production and wetted wall design. In order to investigate the kinetic behavior of double droplets positive collision, this paper mainly combines experimental and numerical simulation methods to investigate the spreading, vibration and fracture characteristics of double droplets of the same volume after collision. Firstly, the rebound vibration of the fused droplet and single droplet is equivalent to a single-degree-of-freedom damped vibration system, and the spreading and vibration characteristics of the single droplet and the double droplets after collision under the same collision velocity are analyzed comparatively by experimental methods. The results show that when the droplet does not fracture, the spreading factor and damping coefficient of single droplet and double droplets gradually increase with the increase of collision velocity, and the vibration time gradually decreases. The damping coefficient and vibration time of the double droplets are higher than that of the single droplet, while the spreading factor is lower than that of the single droplet. Then, the double droplets positive collision phenomenon is studied in depth, and it is found that the spreading factor of the fused droplet increases with the increase of the droplet diameter, the collision velocity, and the wall contact angle. Affected by the low wall temperature, the fused droplet undergoes a phase transition, which affects the bottom flow of the droplet, leading to an increase in the damping coefficient and a decrease in the vibration time. With the decrease of the collision velocity and wall contact angle, the damping coefficient gradually increases and the vibration time decreases. Finally, the numerical simulation method reveals that rebound fracture and spreading fracture phenomena occur after double droplets positive collision, and the critical values of the collision velocity required for the occurrence of rebound fracture and spreading fracture are found. This provides a reliable theoretical basis for the study of the heat and mass transfer process after the collision of multiple droplets on the wall.
{"title":"Study of spreading, vibration, and fracture behavior of double droplets after positive collision","authors":"Jinjuan Sun, Zhiheng Ma, Jianhui Tian, Runling Peng","doi":"10.1177/16878132241260522","DOIUrl":"https://doi.org/10.1177/16878132241260522","url":null,"abstract":"The droplet collision phenomenon is a more complex heat and mass transfer phase transition phenomenon, which is subject to the joint action of kinetics and thermodynamics. During the collision process, the mutual fusion interference of double droplets makes the kinetic mechanism after droplet collision more complicated, and its in-depth study can provide important theoretical support for the fields of engineering applications, industrial production and wetted wall design. In order to investigate the kinetic behavior of double droplets positive collision, this paper mainly combines experimental and numerical simulation methods to investigate the spreading, vibration and fracture characteristics of double droplets of the same volume after collision. Firstly, the rebound vibration of the fused droplet and single droplet is equivalent to a single-degree-of-freedom damped vibration system, and the spreading and vibration characteristics of the single droplet and the double droplets after collision under the same collision velocity are analyzed comparatively by experimental methods. The results show that when the droplet does not fracture, the spreading factor and damping coefficient of single droplet and double droplets gradually increase with the increase of collision velocity, and the vibration time gradually decreases. The damping coefficient and vibration time of the double droplets are higher than that of the single droplet, while the spreading factor is lower than that of the single droplet. Then, the double droplets positive collision phenomenon is studied in depth, and it is found that the spreading factor of the fused droplet increases with the increase of the droplet diameter, the collision velocity, and the wall contact angle. Affected by the low wall temperature, the fused droplet undergoes a phase transition, which affects the bottom flow of the droplet, leading to an increase in the damping coefficient and a decrease in the vibration time. With the decrease of the collision velocity and wall contact angle, the damping coefficient gradually increases and the vibration time decreases. Finally, the numerical simulation method reveals that rebound fracture and spreading fracture phenomena occur after double droplets positive collision, and the critical values of the collision velocity required for the occurrence of rebound fracture and spreading fracture are found. This provides a reliable theoretical basis for the study of the heat and mass transfer process after the collision of multiple droplets on the wall.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"37 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this research, a parabolic trough solar water heater (PTSWH) having helically twisted copper tubes and dimple texturing with an aluminum (AlC) coat was experimentally examined to identify the solar collector’s efficiency, friction factor, convective heat transfer, Nusselt numbers variations, and uncertainty during the test. For this purpose, helical copper dimple tubes with Al coating were used to pass water through it at mass flow rates of 0.5–2.5 kg/min, with 0.5 kg/min increments. Experimental tests were conducted using specific datasets to investigate the efficacy of PTSWH. These experiments aimed to evaluate the efficiency and performance of solar collectors in harnessing solar energy for various applications, such as space heating, water heating, and industrial processes. The results of these experiments are recorded and analyzed to assess the practical viability of solar thermal systems. The results showed that solar collector effectiveness was improved by about 31.2% at flow rates of 1.5 kg/min, while the friction factor was raised by approximately 0.23%. The convective heat transfer coefficient was enhanced by about 7%, and the Nusselt numbers were enhanced to nearly 298. The overall uncertainty of ±2.3% was also observed, indicating that the findings were within the permissible range. Moreover, the PTSWH system recorded an elevated pressure drop of 2.32 kPa. This approach of dimple texturing with Al coating may be best suited for the PTSWHs used in moderate and low solar intensity regions.
{"title":"Experimental analysis of the effect of copper dimple tube with aluminum coating on the performance of parabolic solar water heater using helically twisted tape","authors":"Arun Munusamy, Debabrata Barik, Sreejesh S.R. Chandran, K.E. Reby Roy, Prabhu Paramasivam, Sunil Shreedhara Murthy","doi":"10.1177/16878132241262679","DOIUrl":"https://doi.org/10.1177/16878132241262679","url":null,"abstract":"In this research, a parabolic trough solar water heater (PTSWH) having helically twisted copper tubes and dimple texturing with an aluminum (AlC) coat was experimentally examined to identify the solar collector’s efficiency, friction factor, convective heat transfer, Nusselt numbers variations, and uncertainty during the test. For this purpose, helical copper dimple tubes with Al coating were used to pass water through it at mass flow rates of 0.5–2.5 kg/min, with 0.5 kg/min increments. Experimental tests were conducted using specific datasets to investigate the efficacy of PTSWH. These experiments aimed to evaluate the efficiency and performance of solar collectors in harnessing solar energy for various applications, such as space heating, water heating, and industrial processes. The results of these experiments are recorded and analyzed to assess the practical viability of solar thermal systems. The results showed that solar collector effectiveness was improved by about 31.2% at flow rates of 1.5 kg/min, while the friction factor was raised by approximately 0.23%. The convective heat transfer coefficient was enhanced by about 7%, and the Nusselt numbers were enhanced to nearly 298. The overall uncertainty of ±2.3% was also observed, indicating that the findings were within the permissible range. Moreover, the PTSWH system recorded an elevated pressure drop of 2.32 kPa. This approach of dimple texturing with Al coating may be best suited for the PTSWHs used in moderate and low solar intensity regions.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"46 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work examines the second law analysis of an electrically conducting reactive third-grade fluid flow embedded with the porous medium in a microchannel with the influence of variable thermal conductivity, activation energy, viscous dissipation, joule heating, and radiative heat flux. A suitable non-dimensional variable is included into the governing equations to transform them into an ensemble of equations that are devoid of dimensions. The acquired equations are then tackled using the Runge Kutta Felhberg 4th and 5th order (RKF-45) approach in conjunction with the shooting methodology. Through comparison with the current results, the numerical results are verified, which provides a good agreement. From the present outcomes, it is established that the entropy generation is supreme for the viscous heating constraint, variable thermal conductivity, Frank Kameneski, heat source ratio parameter and third-grade fluid material constraint. The Bejan number boosts up with larger values of activation energy, and Frank Kameneski constraint and the decreasing nature is noticed for increasing third-grade material parameter, viscous heating parameter. With magnetism, the fluid’s velocity slows down because of a resistive force. A similar impact in the channel on velocity is noticed for larger third-grade fluid, activation energy parameter, and Frank-Kameniski parameters and increasing behavior is noticed for variable thermal conductivity, and permeability parameter. Further, it is cleared that the variable thermal conductivity assumption in the channel plate leads to a significant under prediction of the irreversibility rate.
{"title":"Chemically reactive non-Newtonian fluid flow through a vertical microchannel with activation energy impacts: A numerical investigation","authors":"Ajjanna Roja, Pudhari Srilatha, Umair Khan, Anuar Ishak, Anjali Verma, Javare Gowda Rekha, Md Irfanul Haque Siddiqui","doi":"10.1177/16878132241261472","DOIUrl":"https://doi.org/10.1177/16878132241261472","url":null,"abstract":"This work examines the second law analysis of an electrically conducting reactive third-grade fluid flow embedded with the porous medium in a microchannel with the influence of variable thermal conductivity, activation energy, viscous dissipation, joule heating, and radiative heat flux. A suitable non-dimensional variable is included into the governing equations to transform them into an ensemble of equations that are devoid of dimensions. The acquired equations are then tackled using the Runge Kutta Felhberg 4th and 5th order (RKF-45) approach in conjunction with the shooting methodology. Through comparison with the current results, the numerical results are verified, which provides a good agreement. From the present outcomes, it is established that the entropy generation is supreme for the viscous heating constraint, variable thermal conductivity, Frank Kameneski, heat source ratio parameter and third-grade fluid material constraint. The Bejan number boosts up with larger values of activation energy, and Frank Kameneski constraint and the decreasing nature is noticed for increasing third-grade material parameter, viscous heating parameter. With magnetism, the fluid’s velocity slows down because of a resistive force. A similar impact in the channel on velocity is noticed for larger third-grade fluid, activation energy parameter, and Frank-Kameniski parameters and increasing behavior is noticed for variable thermal conductivity, and permeability parameter. Further, it is cleared that the variable thermal conductivity assumption in the channel plate leads to a significant under prediction of the irreversibility rate.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"64 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1177/16878132241259029
Miloš Madić, Velibor Marinković
Laser processing technologies are among the leading industry technologies for efficient and economical processing of a wide spectrum of engineering materials. The determination of optimal parameter settings with respect to multiple and opposite process performances is of great practical importance in laser processing technologies. This paper discusses, analyzes, and compares two main approaches for multi-response optimization (MRO) in engineering, that is, desirability function approach (DFA) and grey relation analysis (GRA), while solving five case studies, covering different laser processing technologies, such as cutting, drilling, welding, micro-channeling, and cladding. In each case study the MRO solutions obtained with two competitive approaches were assessed using the relative target deviation (RTD) criterion. Analysis of the obtained MRO solutions and comparative analysis with results from previous studies indicate that the integrated RSM-GRA provide similar and comparable solutions with the hybrid Taguchi method and GRA, while DFA proved to be a better and more promising approach for solving MRO in laser processing technologies. Some specific features, limitations, and possibilities of MRO approaches were also discussed.
{"title":"Multi-response optimization in laser processing technologies by applying desirability function approach and response surface methodology based on grey relation analysis","authors":"Miloš Madić, Velibor Marinković","doi":"10.1177/16878132241259029","DOIUrl":"https://doi.org/10.1177/16878132241259029","url":null,"abstract":"Laser processing technologies are among the leading industry technologies for efficient and economical processing of a wide spectrum of engineering materials. The determination of optimal parameter settings with respect to multiple and opposite process performances is of great practical importance in laser processing technologies. This paper discusses, analyzes, and compares two main approaches for multi-response optimization (MRO) in engineering, that is, desirability function approach (DFA) and grey relation analysis (GRA), while solving five case studies, covering different laser processing technologies, such as cutting, drilling, welding, micro-channeling, and cladding. In each case study the MRO solutions obtained with two competitive approaches were assessed using the relative target deviation (RTD) criterion. Analysis of the obtained MRO solutions and comparative analysis with results from previous studies indicate that the integrated RSM-GRA provide similar and comparable solutions with the hybrid Taguchi method and GRA, while DFA proved to be a better and more promising approach for solving MRO in laser processing technologies. Some specific features, limitations, and possibilities of MRO approaches were also discussed.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"70 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1177/16878132241260584
Deping Wang, Hongfei Yang, Zongwei Yao, Zhiyong Chang, Yinan Wang
Accurate environmental sensing is an important prerequisite for autonomous driving in off-road environments. Most targets in off-road environments do not have regular shapes, colors, textures and other features, making them difficult to identify. In addition, complex driving conditions can cause large, broadband vibrations in off-road vehicles, which interfere with environment sensing and affect the accuracy and efficiency of perception. To address the above problems, this paper proposes an improved 3D point cloud filtering algorithm for unstructured environments and a point cloud classification method using neural networks, and provides an experimental proof-of-principle of the proposed methods. A comparison of the results under six conditions shows that the amount of data processed by the improved filtering algorithm is 65%–85% of that processed by the conventional filtering algorithm, and the trained neural network model achieves an accuracy of 98.0% and a loss value as low as 0.008 when classifying three typical targets in an unstructured environment. A comparison with algorithms proposed in other papers shows that the proposed method is highly feasible.
{"title":"Neural network-based 3D point cloud detection of targets in unstructured environments","authors":"Deping Wang, Hongfei Yang, Zongwei Yao, Zhiyong Chang, Yinan Wang","doi":"10.1177/16878132241260584","DOIUrl":"https://doi.org/10.1177/16878132241260584","url":null,"abstract":"Accurate environmental sensing is an important prerequisite for autonomous driving in off-road environments. Most targets in off-road environments do not have regular shapes, colors, textures and other features, making them difficult to identify. In addition, complex driving conditions can cause large, broadband vibrations in off-road vehicles, which interfere with environment sensing and affect the accuracy and efficiency of perception. To address the above problems, this paper proposes an improved 3D point cloud filtering algorithm for unstructured environments and a point cloud classification method using neural networks, and provides an experimental proof-of-principle of the proposed methods. A comparison of the results under six conditions shows that the amount of data processed by the improved filtering algorithm is 65%–85% of that processed by the conventional filtering algorithm, and the trained neural network model achieves an accuracy of 98.0% and a loss value as low as 0.008 when classifying three typical targets in an unstructured environment. A comparison with algorithms proposed in other papers shows that the proposed method is highly feasible.","PeriodicalId":7357,"journal":{"name":"Advances in Mechanical Engineering","volume":"32 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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