Pub Date : 2024-01-01DOI: 10.1177/16878132231222906
Jingzhou Gao, Wei Du, Zhenhao Zheng, Shengdun Zhao, Weiming He
Usually, the conventional low-frequency vibration forming machine has a main transmission mechanism as the driving source to provide forming force and an auxiliary mechanism as the vibration source to generate vibration force. The transmission chain is long and the structure is complex and bloated, which affects the forming process and product quality. This paper presents a novel mechatronics idea of low-frequency vibration forming machine, which uses a slotted tubular permanent magnet synchronous linear motor (slotted-TPMLM) as both the driving source and the vibration source. The key is that the slotted-TPMLM provides sufficient forming force accompanied with a certain low-frequency vibration force. Consequently, this paper focuses on the thrust fluctuation caused by the structure. Firstly, the effect of end force and the influence of cogging force are discussed in detail through Fourier analyses, especially the stator adjustment length and pole-slot combination. Then, the slotted-TPMLM is designed, manufactured, and tested. The results show that the slotted-TPMLM can provide a certain low-frequency vibration force (low frequency of 4.8 Hz at 100 mm/s and 48 Hz at 1000 mm/s), which meets the technical requirements. Consequently, the feasibility of the novel mechatronics idea of a low-frequency vibration forming machine has been verified. This research will contribute to the field of linear motors and metal forming machines.
{"title":"Design and utilization of thrust fluctuation of slotted-tubular permanent magnet linear motor: Mechatronics for low-frequency vibration forming machine","authors":"Jingzhou Gao, Wei Du, Zhenhao Zheng, Shengdun Zhao, Weiming He","doi":"10.1177/16878132231222906","DOIUrl":"https://doi.org/10.1177/16878132231222906","url":null,"abstract":"Usually, the conventional low-frequency vibration forming machine has a main transmission mechanism as the driving source to provide forming force and an auxiliary mechanism as the vibration source to generate vibration force. The transmission chain is long and the structure is complex and bloated, which affects the forming process and product quality. This paper presents a novel mechatronics idea of low-frequency vibration forming machine, which uses a slotted tubular permanent magnet synchronous linear motor (slotted-TPMLM) as both the driving source and the vibration source. The key is that the slotted-TPMLM provides sufficient forming force accompanied with a certain low-frequency vibration force. Consequently, this paper focuses on the thrust fluctuation caused by the structure. Firstly, the effect of end force and the influence of cogging force are discussed in detail through Fourier analyses, especially the stator adjustment length and pole-slot combination. Then, the slotted-TPMLM is designed, manufactured, and tested. The results show that the slotted-TPMLM can provide a certain low-frequency vibration force (low frequency of 4.8 Hz at 100 mm/s and 48 Hz at 1000 mm/s), which meets the technical requirements. Consequently, the feasibility of the novel mechatronics idea of a low-frequency vibration forming machine has been verified. This research will contribute to the field of linear motors and metal forming machines.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"145 1‐2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139632571","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231225312
Dongtai Li, Jie Zhang
For autonomous railway vehicle with complex crisscrossed tracks, it is a huge challenge to intelligently detect the trespassers lying in the possible track regions where the train will move along. In order to solve the issue that the existing object detection algorithms detect all obstacles in traffic scene images, a novel strategy YOLOSEG is proposed for intelligent road segmentation and obstacle detection of railway trespasser. Unet is firstly trained to intelligently segment the railway track region where the train is likely to move on, and then the generated region mask is introduced into object detection network for recognizing obstacle within the mask area. The real video of the obstacle emerging in front of the train is difficult to record, therefore the traffic scenes taken from drivers’ perspectives are randomly combined with various obstacles to create the synthetic training dataset which covers various railway traffic scenarios and lighting conditions, and at the same time the label file is automatically generated. Furthermore, a random brightness strategy is proposed for dataset enhancement. By the performance evaluation comparison of FLOPs, Top-1 Accuracy, and mAP@0.5/%, abundant trespasser detection experiments based on synthetic dataset and real images verify the accuracy and effectiveness of the proposed method.
{"title":"Intelligent road segmentation and obstacle detection for autonomous railway vehicle","authors":"Dongtai Li, Jie Zhang","doi":"10.1177/16878132231225312","DOIUrl":"https://doi.org/10.1177/16878132231225312","url":null,"abstract":"For autonomous railway vehicle with complex crisscrossed tracks, it is a huge challenge to intelligently detect the trespassers lying in the possible track regions where the train will move along. In order to solve the issue that the existing object detection algorithms detect all obstacles in traffic scene images, a novel strategy YOLOSEG is proposed for intelligent road segmentation and obstacle detection of railway trespasser. Unet is firstly trained to intelligently segment the railway track region where the train is likely to move on, and then the generated region mask is introduced into object detection network for recognizing obstacle within the mask area. The real video of the obstacle emerging in front of the train is difficult to record, therefore the traffic scenes taken from drivers’ perspectives are randomly combined with various obstacles to create the synthetic training dataset which covers various railway traffic scenarios and lighting conditions, and at the same time the label file is automatically generated. Furthermore, a random brightness strategy is proposed for dataset enhancement. By the performance evaluation comparison of FLOPs, Top-1 Accuracy, and mAP@0.5/%, abundant trespasser detection experiments based on synthetic dataset and real images verify the accuracy and effectiveness of the proposed method.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"52 s40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139633724","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231219612
Feng Wei, Lixiang Zhang, Yeming Zhang, Shuping Li, Ke Yao, Cunjian Li
This paper presents the design of a symmetric variable stiffness joint that employs worm gear and sliding helical transmissions to adjust the effective length of the leaf springs. Firstly, the design concept and working principle of the variable stiffness joint are presented, along with two different assembly methods. Secondly, the stiffness equations and characteristics of the variable stiffness joint are then derived and analyzed. Next, the dynamics of the variable stiffness joint are modeled and simulated visually using Simulink. Finally, a prototype of the variable stiffness joint is constructed and its stiffness characteristics are experimentally verified. The experimental results demonstrate that both assembly methods are capable of adjusting the stiffness and position of the joint within a certain range. This study contributes to the understanding and development of symmetric variable stiffness joints by presenting a comprehensive design, analysis, simulation, and experimental evaluation. The proposed joint has potential applications in various fields that require adaptability, adjustability, and safety.
{"title":"Design and analysis of a novel variable stiffness joints with robots","authors":"Feng Wei, Lixiang Zhang, Yeming Zhang, Shuping Li, Ke Yao, Cunjian Li","doi":"10.1177/16878132231219612","DOIUrl":"https://doi.org/10.1177/16878132231219612","url":null,"abstract":"This paper presents the design of a symmetric variable stiffness joint that employs worm gear and sliding helical transmissions to adjust the effective length of the leaf springs. Firstly, the design concept and working principle of the variable stiffness joint are presented, along with two different assembly methods. Secondly, the stiffness equations and characteristics of the variable stiffness joint are then derived and analyzed. Next, the dynamics of the variable stiffness joint are modeled and simulated visually using Simulink. Finally, a prototype of the variable stiffness joint is constructed and its stiffness characteristics are experimentally verified. The experimental results demonstrate that both assembly methods are capable of adjusting the stiffness and position of the joint within a certain range. This study contributes to the understanding and development of symmetric variable stiffness joints by presenting a comprehensive design, analysis, simulation, and experimental evaluation. The proposed joint has potential applications in various fields that require adaptability, adjustability, and safety.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"39 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139637564","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231226055
Zhirong He, Zhenlin Ji, Yiliang Fan
The three-dimensional frequency-domain linearized Navier-Stokes equations (LNSEs) with consideration of eddy viscosity are developed to evaluate the acoustic attenuation performance of perforated hybrid mufflers in the presence of non-uniform flow. The computations are performed in two steps: time averaged flow variables are acquired by using steady-state computational fluid dynamics (CFD) method and then mapped into the acoustic mesh, and the acoustic perturbation variables are obtained by solving frequency-domain LNSEs, where the sound-absorbing material is treated as an equivalent fluid with complex sound speed and density. The predictions of transmission losses of the two-pass perforated hybrid mufflers in the presence of non-uniform flow are in good consistencies with the measurements, which verifies the correctness of LNSEs. The effect of Mach numbers on acoustic attenuation performance of the mufflers with different filling densities and perforated components is investigated in detail. The transmission loss of the mufflers with various filling densities are increased by complex airflow in the lower frequency range. For the mufflers where not all components have been perforated, the flow lowers low-frequency resonance peak. The influence of complex airflow on acoustic attenuation performance of all configurations is weakened at higher frequencies.
{"title":"Acoustic attenuation prediction and analysis of perforated hybrid mufflers with non-uniform flow based on frequency domain linearized Navier-Stokes equations","authors":"Zhirong He, Zhenlin Ji, Yiliang Fan","doi":"10.1177/16878132231226055","DOIUrl":"https://doi.org/10.1177/16878132231226055","url":null,"abstract":"The three-dimensional frequency-domain linearized Navier-Stokes equations (LNSEs) with consideration of eddy viscosity are developed to evaluate the acoustic attenuation performance of perforated hybrid mufflers in the presence of non-uniform flow. The computations are performed in two steps: time averaged flow variables are acquired by using steady-state computational fluid dynamics (CFD) method and then mapped into the acoustic mesh, and the acoustic perturbation variables are obtained by solving frequency-domain LNSEs, where the sound-absorbing material is treated as an equivalent fluid with complex sound speed and density. The predictions of transmission losses of the two-pass perforated hybrid mufflers in the presence of non-uniform flow are in good consistencies with the measurements, which verifies the correctness of LNSEs. The effect of Mach numbers on acoustic attenuation performance of the mufflers with different filling densities and perforated components is investigated in detail. The transmission loss of the mufflers with various filling densities are increased by complex airflow in the lower frequency range. For the mufflers where not all components have been perforated, the flow lowers low-frequency resonance peak. The influence of complex airflow on acoustic attenuation performance of all configurations is weakened at higher frequencies.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"123 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139639597","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231223027
M Vinodkumar Reddy, M. Ajithkumar, S. Lone, Farhan Ali, P. Lakshminarayana, Anwar Saeed
The current investigation explores the effect of activation energy on the MHD radiative Williamson nanofluid flow across a wedge using heat generation and binary chemical reactivity. The flow model consists of partial differential equations (PDEs) by transforming them into ordinary differential equations (ODEs). Numerical computations have been carried out through the bvp4c MATLAB package. The most effective solutions for flow profiles have been displayed through graphs, while the numeric solutions for the drag friction, heat, and mass transport have been displayed via tables. Numerical findings demonstrate that the temperature field is accelerated by the increase in radiation parameter. In addition, it is intriguing to discover that the concentration boundary layer thickness improves as the activation energy increases. A fundamental study further reveals that the local skin friction coefficient is a rising function of thermal and concentration Grashof numbers. Moreover, it is concluded that the enhanced Brownian motion, thermophoresis, and Eckert number decline the heat transfer rate.
{"title":"Magneto-Williamson nanofluid flow past a wedge with activation energy: Buongiorno model","authors":"M Vinodkumar Reddy, M. Ajithkumar, S. Lone, Farhan Ali, P. Lakshminarayana, Anwar Saeed","doi":"10.1177/16878132231223027","DOIUrl":"https://doi.org/10.1177/16878132231223027","url":null,"abstract":"The current investigation explores the effect of activation energy on the MHD radiative Williamson nanofluid flow across a wedge using heat generation and binary chemical reactivity. The flow model consists of partial differential equations (PDEs) by transforming them into ordinary differential equations (ODEs). Numerical computations have been carried out through the bvp4c MATLAB package. The most effective solutions for flow profiles have been displayed through graphs, while the numeric solutions for the drag friction, heat, and mass transport have been displayed via tables. Numerical findings demonstrate that the temperature field is accelerated by the increase in radiation parameter. In addition, it is intriguing to discover that the concentration boundary layer thickness improves as the activation energy increases. A fundamental study further reveals that the local skin friction coefficient is a rising function of thermal and concentration Grashof numbers. Moreover, it is concluded that the enhanced Brownian motion, thermophoresis, and Eckert number decline the heat transfer rate.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"16 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139632773","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132241227115
Li-Hsiang Chien, J. Juang
Most aircraft accidents occurred during the final approach. Wind disturbance is one of the significant factors in these accidents. During the landing phase, the Automatic Landing System (ALS) can help aircraft land safely and significantly reduce the pilot’s work loading. Control schemes of the conventional ALS usually use gain-scheduling and traditional PID control techniques. A traditional controller cannot control the aircraft if the weather conditions are beyond the allowed limits. To improve the performance of the landing control, this study applies a linguistic fuzzy neural network (LFNN) to replace the conventional controller of ALS. Adaptive learning rules are proposed to enhance the LFNN control ability. The method used to obtain adaptive learning rules is the Lyapunov stability theory. Moreover, the convergence of the system performance error is proved by the Lyapunov theory. This study also compares previously proposed control schemes in aircraft landing control. Different turbulence strengths are implemented into the flight simulation to make the proposed controller more robust and adaptive to various wind disturbance conditions. The LFNN controller can successfully overcome 75 ft/s wind speed, while the adaptive LFNN can reach 80 ft/s with optimal learning rates. Using optimal convergence theorems, the proposed controller performs better than the controllers trained by a fixed learning rate.
{"title":"Application of linguistic fuzzy neural network to landing control","authors":"Li-Hsiang Chien, J. Juang","doi":"10.1177/16878132241227115","DOIUrl":"https://doi.org/10.1177/16878132241227115","url":null,"abstract":"Most aircraft accidents occurred during the final approach. Wind disturbance is one of the significant factors in these accidents. During the landing phase, the Automatic Landing System (ALS) can help aircraft land safely and significantly reduce the pilot’s work loading. Control schemes of the conventional ALS usually use gain-scheduling and traditional PID control techniques. A traditional controller cannot control the aircraft if the weather conditions are beyond the allowed limits. To improve the performance of the landing control, this study applies a linguistic fuzzy neural network (LFNN) to replace the conventional controller of ALS. Adaptive learning rules are proposed to enhance the LFNN control ability. The method used to obtain adaptive learning rules is the Lyapunov stability theory. Moreover, the convergence of the system performance error is proved by the Lyapunov theory. This study also compares previously proposed control schemes in aircraft landing control. Different turbulence strengths are implemented into the flight simulation to make the proposed controller more robust and adaptive to various wind disturbance conditions. The LFNN controller can successfully overcome 75 ft/s wind speed, while the adaptive LFNN can reach 80 ft/s with optimal learning rates. Using optimal convergence theorems, the proposed controller performs better than the controllers trained by a fixed learning rate.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"4 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139632073","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231223872
S. A. Shehzad, Rabia Farid
The comparative analysis of non-Newtonian nanofluids with Newtonian conditions are addressed in this research. Oldroyd-B and Casson fluids are adopted as the non-Newtonian fluids (NNF). The generation of flow is due to bidirectionally movement of magnetized surface. Radiation and chemical reactive processes are accounted in energy and mass transportation equations. Buongiorno’s theory of nanoparticles is developed for the nanofluids analysis. The basic formulas of fluid dynamics are incorporated to formulate the physical model. The assumption of boundary-layer is utilized for the simplification of mathematical model. The arising nonlinear model of three independent variables are converted into one independent variable model using similarity constraints. The simplified mathematical model is treated analytically through the implementation of homotopic approach. The convergence of this scheme is verified through numerical benchmark and graphic illustration. The results of versatile constraints on physical quantities are addressed numerically and graphically. The comparison of results with previous published outcomes is provided in limiting approach.
{"title":"Comparative analysis of oldroyd-b and casson nanofluids flowing through chemically reactive radiative porous medium","authors":"S. A. Shehzad, Rabia Farid","doi":"10.1177/16878132231223872","DOIUrl":"https://doi.org/10.1177/16878132231223872","url":null,"abstract":"The comparative analysis of non-Newtonian nanofluids with Newtonian conditions are addressed in this research. Oldroyd-B and Casson fluids are adopted as the non-Newtonian fluids (NNF). The generation of flow is due to bidirectionally movement of magnetized surface. Radiation and chemical reactive processes are accounted in energy and mass transportation equations. Buongiorno’s theory of nanoparticles is developed for the nanofluids analysis. The basic formulas of fluid dynamics are incorporated to formulate the physical model. The assumption of boundary-layer is utilized for the simplification of mathematical model. The arising nonlinear model of three independent variables are converted into one independent variable model using similarity constraints. The simplified mathematical model is treated analytically through the implementation of homotopic approach. The convergence of this scheme is verified through numerical benchmark and graphic illustration. The results of versatile constraints on physical quantities are addressed numerically and graphically. The comparison of results with previous published outcomes is provided in limiting approach.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"22 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139634935","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231219487
Xin Ye, Zhenggui Zhou
The flow loss in the blade passage of a supersonic compressor rotor mainly comes from the boundary layers on the blade surface and end wall, the shock wave, the shock wave/boundary layer interaction, and tip leakage flow; the instability is mainly caused by the shock wave near the rotor blade tip exiting the blade passage. This paper adopts an internal slot in the blade, with the inlet of the slot located at the leading edge of the blade and the outlet located on the suction surface of the blade, by using the momentum of the incoming flow to form a high-velocity jet to control the flow loss and improve the stall margin of the supersonic rotor. The mechanism of reducing flow loss by a slotting jet was studied, and a genetic algorithm optimization platform was further used for the coupled optimization design of the slot and blade. The numerical calculation results showed that the slotting jet can effectively suppress the development of the boundary layer on the suction surface while reducing the intensity of the shock wave, thereby reducing the loss of the boundary layer and shock wave, significantly improving the peak efficiency of the rotor, and increasing the mass flow rate at the peak efficiency point. The slotting jet can cause the shock wave in the passage to move downstream, thereby improving the stall margin of the rotor. Due to the strong shock wave in the blade passage near the blade tip, the slot outlet should be near and upstream of the shock wave; the shock wave in the middle and root regions of the blade is weaker, and the slot outlet should be located downstream of the shock wave.
{"title":"Controlling the flow loss of a supersonic compressor rotor using the blade slotting method","authors":"Xin Ye, Zhenggui Zhou","doi":"10.1177/16878132231219487","DOIUrl":"https://doi.org/10.1177/16878132231219487","url":null,"abstract":"The flow loss in the blade passage of a supersonic compressor rotor mainly comes from the boundary layers on the blade surface and end wall, the shock wave, the shock wave/boundary layer interaction, and tip leakage flow; the instability is mainly caused by the shock wave near the rotor blade tip exiting the blade passage. This paper adopts an internal slot in the blade, with the inlet of the slot located at the leading edge of the blade and the outlet located on the suction surface of the blade, by using the momentum of the incoming flow to form a high-velocity jet to control the flow loss and improve the stall margin of the supersonic rotor. The mechanism of reducing flow loss by a slotting jet was studied, and a genetic algorithm optimization platform was further used for the coupled optimization design of the slot and blade. The numerical calculation results showed that the slotting jet can effectively suppress the development of the boundary layer on the suction surface while reducing the intensity of the shock wave, thereby reducing the loss of the boundary layer and shock wave, significantly improving the peak efficiency of the rotor, and increasing the mass flow rate at the peak efficiency point. The slotting jet can cause the shock wave in the passage to move downstream, thereby improving the stall margin of the rotor. Due to the strong shock wave in the blade passage near the blade tip, the slot outlet should be near and upstream of the shock wave; the shock wave in the middle and root regions of the blade is weaker, and the slot outlet should be located downstream of the shock wave.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139635238","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231226056
Chengyi Zheng, Zheyan Jin, Qiaotian Dong, Zhigang Yang
The complexity of ice accretion shapes on aircraft brings challenges in establishing the physical correlations between the geometric parameters of ice and the aerodynamic performances of an airfoil. The present study applied a quarter-circle simplified ridge ice model and designed four parameters, including the lower ice horn, the height of the upper ice horn, the angle of the upper ice horn, and the location of the upper ice horn. Design of Experiments (DOE) was adopted to design the simulation process and analyze the obtained data. Numerical investigations were carried out to study the effects of these four design parameters on the lift coefficients ( CL) and drag coefficients ( CD) of three airfoils at various angles of attack. The results revealed that the four design parameters had influences on CL and CD in all simulation cases. The influence of the height of the upper ice horn was always dominant, followed by the angle and location of the upper ice horn. The influence degrees of the lower ice horn varied with the angles of attack and airfoils. The change trends of CL and CD were opposite while changing the value of any parameter in most simulation cases. In addition, the leading-edge radii of these three airfoils, as well as the shapes of the upper and lower surfaces, could alter the influences of design parameters on CL and CD.
飞机上的积冰形状复杂，给建立冰的几何参数与机翼气动性能之间的物理关联带来了挑战。本研究采用四分之一圆简化脊冰模型，设计了四个参数，包括下冰角、上冰角高度、上冰角角度和上冰角位置。采用实验设计（DOE）来设计模拟过程并分析获得的数据。数值研究了这四个设计参数对三个翼面在不同攻角下的升力系数（CL）和阻力系数（CD）的影响。结果表明，在所有模拟情况下，四个设计参数都对 CL 和 CD 有影响。上冰角高度的影响始终占主导地位，其次是上冰角的角度和位置。下冰角的影响程度随攻角和翼面的变化而变化。在大多数模拟情况下，在改变任何参数值时，CL 和 CD 的变化趋势都是相反的。此外，这三种翼面的前缘半径以及上下表面的形状也会改变设计参数对 CL 和 CD 的影响。
{"title":"Numerical investigation of the influences of ridge ice parameters on lift and drag coefficients of airfoils through design of experiments","authors":"Chengyi Zheng, Zheyan Jin, Qiaotian Dong, Zhigang Yang","doi":"10.1177/16878132231226056","DOIUrl":"https://doi.org/10.1177/16878132231226056","url":null,"abstract":"The complexity of ice accretion shapes on aircraft brings challenges in establishing the physical correlations between the geometric parameters of ice and the aerodynamic performances of an airfoil. The present study applied a quarter-circle simplified ridge ice model and designed four parameters, including the lower ice horn, the height of the upper ice horn, the angle of the upper ice horn, and the location of the upper ice horn. Design of Experiments (DOE) was adopted to design the simulation process and analyze the obtained data. Numerical investigations were carried out to study the effects of these four design parameters on the lift coefficients ( CL) and drag coefficients ( CD) of three airfoils at various angles of attack. The results revealed that the four design parameters had influences on CL and CD in all simulation cases. The influence of the height of the upper ice horn was always dominant, followed by the angle and location of the upper ice horn. The influence degrees of the lower ice horn varied with the angles of attack and airfoils. The change trends of CL and CD were opposite while changing the value of any parameter in most simulation cases. In addition, the leading-edge radii of these three airfoils, as well as the shapes of the upper and lower surfaces, could alter the influences of design parameters on CL and CD.","PeriodicalId":502561,"journal":{"name":"Advances in Mechanical Engineering","volume":"23 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139631599","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}
Pub Date : 2024-01-01DOI: 10.1177/16878132231225321
Xiaoyu Huo, Yanan Guo
A flexible reinforcement learning (RL) optimal collision-avoidance control formulation for unmanned aerial vehicles (UAVs) with discrete-time frameworks is revealed in this work. By utilizing the neural network (NN) estimating capacity and the actor-critic control scheme of the RL technique, an adaptive RL optimal collision-free controller with a minimal learning parameter (MLP) is formulated, which is based on a novel strategic utility function. The optimal collision-avoidance control issue, which couldn’t be addressed in the prior literature, can be resolved by the suggested approaches. Furthermore, the proposed MPL adaptive optimal control formulation allows for a reduction in the quantity of adaptive laws, leading to reduced computational complexity. Additionally, a rigorous stability analysis is provided, demonstrating that the uniform ultimate boundedness (UUB) of all signals in the closed-loop system is ensured by the proposed adaptive RL. Finally, the simulation outcomes illustrate the effectiveness of the proposed optimal RL control approaches.
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