Frontiers in Mechanical Engineering最新文献_第9页

Effects of low and high frequency actuation on aerodynamic performance of a supercritical airfoil 低频和高频驱动对超临界机翼气动性能的影响

IF 2.3

Frontiers in Mechanical Engineering Pub Date : 2023-11-22 DOI: 10.3389/fmech.2023.1290074

Soheila Abdolahipour

{"title":"Effects of low and high frequency actuation on aerodynamic performance of a supercritical airfoil","authors":"Soheila Abdolahipour","doi":"10.3389/fmech.2023.1290074","DOIUrl":"https://doi.org/10.3389/fmech.2023.1290074","url":null,"abstract":"The main objective of this study is to investigate the effects of low and high frequency actuation in improving the aerodynamic performance of the supercritical airfoil with the approach of using it in a high-lift or flight control device. For this purpose, a flow control numerical simulation is performed on a supercritical airfoil with NASA SC(2)-0714 cross section using a pulsed jet at the chord-based Reynolds number of 1 × 106. The pulsed jet actuation with different reduced frequencies of 0.2, 1, 1.2, 2.4, 4, 6, and 12 is implemented on the upper side of the airfoil surface upstream of the separation point of the uncontrolled case. The aerodynamic efficiency improvements are investigated by extracting the results of time-averaged and instantaneous aerodynamic forces for all cases. The study compares the flow streamline, Q-criterion contour, and surface pressure distribution to examine how the separated flow configuration over the airfoil responds to different actuation frequencies. The results indicate that pulsed jet actuation effectively postpones the flow separation. A comparison of the time-averaged aerodynamic coefficients at different actuation frequencies revealed that utilizing a low actuation frequency range maximizes lift, while a high frequency range minimizes drag. In addition, the aerodynamic efficiency of the supercritical airfoil improves across all controlled scenarios, with the optimal increase in aerodynamic efficiency of 28.62% achieved at an actuation frequency of F+ = 1.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139249417","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

Dual-mode 3D printed dynamic wrist driven orthosis for hand therapy exercises 用于手部治疗运动的双模式 3D 打印动态腕部驱动矫形器

IF 2.3

Frontiers in Mechanical Engineering Pub Date : 2023-11-22 DOI: 10.3389/fmech.2023.1286304

A. G. Risangtuni, S. Suprijanto, Y. Y. Nazaruddin, A. Mahyuddin

{"title":"Dual-mode 3D printed dynamic wrist driven orthosis for hand therapy exercises","authors":"A. G. Risangtuni, S. Suprijanto, Y. Y. Nazaruddin, A. Mahyuddin","doi":"10.3389/fmech.2023.1286304","DOIUrl":"https://doi.org/10.3389/fmech.2023.1286304","url":null,"abstract":"The primary objective of the Dual-mode Dynamic Wrist Driven Orthosis (D-WDO) is to facilitate wrist-hand therapy exercises for patients with varying levels of residual muscle function. This dual-mode D-WDO system comprises two main components: the orthosis structure and the soft pneumatic actuator (SPA). All system components were designed and produced using Computer Aided Design (CAD) software and the Fused Deposition Modeling (FDM) 3D printing technique. The D-WDO’s structure is constructed from PLA (Polylactic Acid), while the SPA is made from TPU (Thermoplastic Polyurethane) filament. The D-WDO can be operated in passive or active mode by attaching or detaching the SPA from the structure. This D-WDO system is particularly suitable for patients with a minimum MMT level between 2 and 3, as it provides assistance for wrist movement and supports repetitive wrist motion to enhance wrist muscle function. However, it is important to note that the operation and performance of the dual-mode D-WDO system may vary depending on the chosen system configuration. The active D-WDO’s performance demonstrates its ability to achieve the necessary wrist flexion angle for a functional wrist joint, especially in the context of daily activities.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139248723","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

Editorial: Global excellence in digital manufacturing: Europe 社论：全球卓越的数字化制造：欧洲

IF 2.3

Frontiers in Mechanical Engineering Pub Date : 2023-11-21 DOI: 10.3389/fmech.2023.1334600

R. Furferi, Asif Ur Rehman

引用次数: 0

Mechanical analysis of helmeted headforms under ballistic impact with implications in performance evaluation of ballistic helmets 头盔头模在弹道冲击下的力学分析及其对防弹头盔性能评估的影响

IF 2.3

Frontiers in Mechanical Engineering Pub Date : 2023-11-17 DOI: 10.3389/fmech.2023.1270905

Atul Harmukh, Abhilash Singh, Praveen Kumar, Sanjeev K. Verma, Pal Dinesh Kumar, S. G. Ganpule

{"title":"Mechanical analysis of helmeted headforms under ballistic impact with implications in performance evaluation of ballistic helmets","authors":"Atul Harmukh, Abhilash Singh, Praveen Kumar, Sanjeev K. Verma, Pal Dinesh Kumar, S. G. Ganpule","doi":"10.3389/fmech.2023.1270905","DOIUrl":"https://doi.org/10.3389/fmech.2023.1270905","url":null,"abstract":"Behind helmet blunt trauma is a significant health concern in modern warfare. The ballistic response of the human head under ballistic impact is highly sought. Towards this end, we conducted ballistic experiments on three different headforms. The following headforms were considered: a) National Institute of Justice based rigid headform, b) Hybrid-III based flexible headform, and c) head model based headform. Headforms b, c were assembled with the Hybrid-III neck. An advanced combat helmet was fitted to the headforms. Helmet-head assembly was subjected to a 9 mm × 19 mm full metal jacket projectile having velocities of 430 ± 15 m/s. The response of the head surrogate in the front, back, side, and crown orientations was studied. Back face deformation (BFD), head kinematics, and intracranial pressures in headforms were measured. In addition, equivalent stress and maximum principal strain in the brain were obtained using concurrent finite element simulations. Results suggest that both local (i.e., due to the localized crushing of the helmet) and global (i.e., due to the bulk motion of the helmet-head parenchyma) responses were dominant under investigated ballistic impacts. Further, the type of the headform affected the biomechanical response. As compared to the rigid headform, a statistically significant increase in head kinematics was observed with the flexible headforms; changes in BFD were statistically insignificant. The orientation dependent responses have been observed. Overall, these results provide novel insights regarding the ballistic response of the headforms with the combat helmet and underscore critical considerations during the ballistic evaluation of helmets.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139263832","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

Kirigami-inspired deployable mechanisms with a type-preserving feature and controllable Poisson’s ratio 具有保型特征和可控泊松比的叽里呱啦启发式可部署机构

IF 2.3

Frontiers in Mechanical Engineering Pub Date : 2023-11-16 DOI: 10.3389/fmech.2023.1225682

Jianzhi Wang, Hang Xiao, Xilun Ding, Shengnan Lyu

{"title":"Kirigami-inspired deployable mechanisms with a type-preserving feature and controllable Poisson’s ratio","authors":"Jianzhi Wang, Hang Xiao, Xilun Ding, Shengnan Lyu","doi":"10.3389/fmech.2023.1225682","DOIUrl":"https://doi.org/10.3389/fmech.2023.1225682","url":null,"abstract":"A spatial deployable mechanism is capable of adapting to different operating requirements by adjusting its shape and size. However, most current deployable mechanisms fail to maintain the type of their reflective surface during the folding process, which limits their ability to adjust the optimal operating frequency. To address this issue, this paper presents a novel design of a deployable mechanism with a type-preserving feature inspired by kirigami techniques. By preserving the type of its reflective surface, this mechanism allows for the adjustment of the optimum operating frequency according to specific requirements. This makes it well-suited for deployment on commercial satellites that undergo constant mission variations. The mechanism is constructed using porous kirigami cells, ensuring that the type of the working surface is maintained throughout the deployment process. The construction of deployable units and networks based on porous cells is also discussed. Additionally, deployable mechanisms with controllable Poisson’s ratios are developed. The kinematics of the mechanism are analyzed to verify the type-preserving characteristics. Finally, four case studies are conducted to illustrate and validate the proposed design and analysis.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139268458","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

Experimental study on the nozzle-shape effect on liquid jet characteristics in gaseous crossflow 喷嘴形状对气态横流中液体射流特性影响的实验研究

IF 2.3

Frontiers in Mechanical Engineering Pub Date : 2023-11-15 DOI: 10.3389/fmech.2023.1207894

B. Jalili, P. Jalili, F. Ommi, D. D. Ganji

{"title":"Experimental study on the nozzle-shape effect on liquid jet characteristics in gaseous crossflow","authors":"B. Jalili, P. Jalili, F. Ommi, D. D. Ganji","doi":"10.3389/fmech.2023.1207894","DOIUrl":"https://doi.org/10.3389/fmech.2023.1207894","url":null,"abstract":"This study presents experimental findings on the crossflow injection of a liquid jet into a gaseous flow. Crossflow injection is favored over co-axial trajectory injection because of its potential to enhance atomization, promote the formation of smaller droplets, and improve injection parameters, mainly due to the differing trajectory of fuel injection within the transverse airflow. The study’s experiments use two circular and four elliptical nozzles with varying aspect ratios. The research investigates the influential factors that affect the trajectory and breakup of the liquid jet, specifically analyzing the impact of the nozzle geometry, Weber number, and momentum ratio of the liquid jet to the air crossflow. Additionally, equations are derived to describe the trajectory for both elliptical and circular nozzles. The relationship between breakup height and length is explored, with the observation that breakup length remains constant for both nozzle shapes. Furthermore, the study investigates the analysis of breakup regimes and establishes a direct correlation between the Weber number and the breakup regime. Column, bag, and multimode breakup are observed at Weber numbers 4, 38, and 82, respectively. The experimental error for the liquid jet trajectory obtained is approximately 2%. Importantly, the experimental results align with previously published experimental and numerical data, confirming the validity and reliability of the findings.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139274585","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

Electric ducted fan controller and self-balancing system for two-wheeler motorbike 用于两轮摩托车的电动风道风扇控制器和自平衡系统

IF 2.3

Frontiers in Mechanical Engineering Pub Date : 2023-11-15 DOI: 10.3389/fmech.2023.1284879

Mamon M. Horoub, Ammar Alzaydi, A. A. Hanieh

{"title":"Electric ducted fan controller and self-balancing system for two-wheeler motorbike","authors":"Mamon M. Horoub, Ammar Alzaydi, A. A. Hanieh","doi":"10.3389/fmech.2023.1284879","DOIUrl":"https://doi.org/10.3389/fmech.2023.1284879","url":null,"abstract":"A new method of achieving self-balancing for two-wheeled vehicles is described in this paper. The structure is characterized by the presence of two electric ducted fans which are designed to blow air in the opposite direction of the fall in order to maintain equilibrium. Due to their ability to move in two degrees of freedom, Electric Ducted Fans motors are able to propel and lower the weight of the two-wheeler while remaining stable. It is described how the Proportional-Integral-Differential arducopter controller works, which employs an Inertial Measurement Unit sensor and a nonlinear complementary filter on particular orthogonal arrangements to determine the lean angles at any specific time, as well as a feedback loop to maintain the system at the required upright 0° lean angle at all times. Following that, the proposed Proportional-Integral-Differential controller is tested on a small-scale model in order to verify the proposed idea of self-balancing using Electric Ducted Fans motors. Mathematical modeling for the small-scale model has been calculated. Then the response of the Proportional-Integral-Differential controller for lean angle against external disturbances is tested theoretically and experimentally. After obtaining positive outcomes on the small-scale model, the concept that has been suggested is evaluated versus a large-scale design (motorbike) by constructing the mechanical and electrical components. The process breaks down into three primary phases: design and fabrication of mechanical parts, design of electrical components, and design of control systems. The innovative aspect of this work is the introduction of a method for achieving self-balancing in two-wheeled vehicles using electric ducted fans.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139272836","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

High-temperature tribological properties of Co-29Cr-6Mo alloy fabricated by selective laser melting process 选择性激光熔制Co-29Cr-6Mo合金的高温摩擦学性能

Frontiers in Mechanical Engineering Pub Date : 2023-11-10 DOI: 10.3389/fmech.2023.1289450

Maziar Ramezani, Zaidi Mohd Ripin

引用次数: 0

Characterization of wind turbine flow through nacelle-mounted lidars: a review 通过安装在机舱内的激光雷达表征风力涡轮机流动:综述

Frontiers in Mechanical Engineering Pub Date : 2023-11-02 DOI: 10.3389/fmech.2023.1261017

Stefano Letizia, Peter Brugger, Nicola Bodini, Raghavendra Krishnamurthy, Andrew Scholbrock, Eric Simley, Fernando Porté-Agel, Nicholas Hamilton, Paula Doubrawa, Patrick Moriarty

引用次数: 0

Tribological evaluation of electric vehicle driveline lubricants in an electrified environment 电气化环境下电动汽车传动系润滑油的摩擦学评价

Frontiers in Mechanical Engineering Pub Date : 2023-11-02 DOI: 10.3389/fmech.2023.1215352

Peter M. Lee, Carlos Sanchez, Cole Frazier, Andrew Velasquez, Travis Kostan

{"title":"Tribological evaluation of electric vehicle driveline lubricants in an electrified environment","authors":"Peter M. Lee, Carlos Sanchez, Cole Frazier, Andrew Velasquez, Travis Kostan","doi":"10.3389/fmech.2023.1215352","DOIUrl":"https://doi.org/10.3389/fmech.2023.1215352","url":null,"abstract":"Electrification continues to permeate the automotive industry, with future projections showing an exponential growth in the market share for both light and heavy-duty applications. Existing test methods for automotive applications were developed to model internal combustion engine vehicles and drivelines and are not appropriate for electric drivelines that experience stray electric currents. Tribometers can be used to evaluate friction and wear on modeled surfaces simulating in-vehicle operation. In this work, a commercially available tribometer was modified to isolate an electrical input into a tribological contact. After necessary modifications to the tribometer, a test matrix was completed for investigating different temperatures, load conditions, speed conditions, voltage input types, frequencies of AC signal, and shapes of AC signal. These parameters were tested on three lubricants—two typical automatic transmission fluid formulations and gear oil used in differential applications. Friction was measured throughout the tests, and wear scar width was measured at the end of each test. Results indicated that temperature, DC voltage, AC frequency, lubricant, and test profile had statistically significant differences in wear scar width. For electrical parameters, AC frequency produced different results from DC voltage when no voltage was applied. This significance applied to only one lubricant, with the other two lubricants having mixed results.","PeriodicalId":53220,"journal":{"name":"Frontiers in Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135973689","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