Frontiers of Mechanical Engineering最新文献_第5页

Insensitivity to propagation timing in a preview-enabled wind turbine control experiment 风力机控制实验中对传播时间的不敏感性

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-05-23 DOI: 10.3389/fmech.2023.1145305

M. Sinner, V. Petrović, David Stockhouse, A. Langidis, M. Pusch, M. Kühn, L. Pao

{"title":"Insensitivity to propagation timing in a preview-enabled wind turbine control experiment","authors":"M. Sinner, V. Petrović, David Stockhouse, A. Langidis, M. Pusch, M. Kühn, L. Pao","doi":"10.3389/fmech.2023.1145305","DOIUrl":"https://doi.org/10.3389/fmech.2023.1145305","url":null,"abstract":"Lidar scanners are capable of taking measurements of a wind field upstream of a wind turbine. The wind turbine controller can use these measurements as a “preview” of future disturbances impacting the turbine. Such preview-enabled (or feedforward) controllers show superior performance to standard wind turbine control configurations based purely on a feedback architecture. To capitalize on the performance improvements that preview wind measurements can provide, feedforward control actions should be timed to coincide with the arrival of the wind field at the wind turbine location. However, the time of propagation of the wind field between the lidar measurement location and the wind turbine is not perfectly known. Moreover, the best time to take feedforward control action may not perfectly coincide with the true arrival time of the wind disturbance. This contribution presents results from an experiment where preview-enabled model predictive control was deployed on a fully-actuated, scaled model wind turbine operating in a wind tunnel testbed. In the study, we investigate the sensitivity of the controller performance to the assumed propagation delay using a range of wind input sequences. We find that the preview-enabled controller outperforms the feedback only case across a wide range of assumed propagation delays, demonstrating a level of robustness to the time alignment of the incoming disturbances.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46075553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Binary liquid film condensation from water-ammonia vapors mixture flowing downward along a parallel plate condenser 沿着平行板冷凝器向下流动的水-氨-蒸汽混合物的二元液膜冷凝

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-05-22 DOI: 10.3389/fmech.2023.1148246

A. Nasr, Ahmed Nassif, A. Al-Ghamdi

{"title":"Binary liquid film condensation from water-ammonia vapors mixture flowing downward along a parallel plate condenser","authors":"A. Nasr, Ahmed Nassif, A. Al-Ghamdi","doi":"10.3389/fmech.2023.1148246","DOIUrl":"https://doi.org/10.3389/fmech.2023.1148246","url":null,"abstract":"The ammonia-water film condensation is used as an efficient working fluid in industrial applications such as refrigeration, plate condenser and evaporator, absorber/generator heat exchange, air-conditioning, heat pumps and separation processes. The present work focuses on a numerical investigation of water-ammonia condensation on a falling binary liquid film inside a parallel plate condenser by mixed convection. The parallel plate condenser is composed by two parallel vertical plates. One of the plates is wetted by liquidfilm and cooled by the thermal flux cooling while the other plate is isothermal and dry. Parametric computations were performed to investigate the effects of the inlet parameters of gas, the properties of the binary liquid film as well as the thermal flux cooling on the combined mass and heat transfer and on the efficiency of the parallel plate condenser. The results show that an increase in the inlet vapor of ammonia as well as of vapor water enhances the efficiency of the parallel plate condenser. It is shown also that an enhancement of efficiency of the parallel plate condenser has been recorded when the thermal flux cooling and inlet liquid flow rate is elevated. Whereas the increase of the inlet liquid concentration of ammonia inhibits the efficiency of the parallel plate condenser.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45053518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design and evaluation of a novel biopsy needle with hemostatic function 具有止血功能的新型活检针的设计与评价

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-05-19 DOI: 10.1007/s11465-022-0738-7

Xiaolong Zhu, Yichi Ma, Xuesu Xiao, Liang Lu, Wei Xiao, Ziqi Zhao, Hongliang Ren, Max Q.-H. Meng

引用次数: 0

Design and modeling of continuum robot based on virtual-center of motion mechanism 基于虚拟运动中心机构的连续体机器人设计与建模

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-05-17 DOI: 10.1007/s11465-022-0739-6

Guoxin Li, Jingjun Yu, Yichao Tang, Jie Pan, S. Cao, X. Pei

引用次数: 0

Build orientation determination of multi-feature mechanical parts in selective laser melting via multi-objective decision making 基于多目标决策的多特征机械零件的定向确定

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-05-17 DOI: 10.1007/s11465-022-0737-8

Hongsheng Sheng, Jinghua Xu, Shuyou Zhang, Jianrong Tan, Kang Wang

引用次数: 0

Editorial: The mechanobiology of collagen remodeling in health and disease 编辑:健康和疾病中胶原重塑的机械生物学

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-05-09 DOI: 10.3389/fmech.2023.1211250

Ehsan Ban, B. Freedman, Lucas R. Smith, R. Wells

引用次数: 0

Design and characteristic research of a novel electromechanical-hydraulic hybrid actuator with two transmission mechanisms 一种新型双传动机电液混合作动器的设计与特性研究

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-05-05 DOI: 10.1007/s11465-022-0735-x

Shufei Qiao, Long Quan, Yunxiao Hao, Lei Ge, Lianpeng Xia

引用次数: 0

Collaborative control for in situ monitoring of molten pool in selective laser melting 选择性激光熔化熔池现场监测的协同控制

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-04-26 DOI: 10.3389/fmech.2023.1123751

Xin Lin, Bing Liu, Anchao Shen, Zhiwei Cui, K. Zhu

{"title":"Collaborative control for in situ monitoring of molten pool in selective laser melting","authors":"Xin Lin, Bing Liu, Anchao Shen, Zhiwei Cui, K. Zhu","doi":"10.3389/fmech.2023.1123751","DOIUrl":"https://doi.org/10.3389/fmech.2023.1123751","url":null,"abstract":"In situ monitoring during the selective laser melting (SLM) process is a promising solution to mitigate defects and improve the quality of as-built parts. However, the existing monitoring platform lacks collaborative control of the process monitoring components, and as a result, it cannot realize a real-time and accurate signal acquisition at a close distance and multiple angles during the whole printing process. In this paper, driven by multiple motors, an off-axis monitoring platform is constructed that enables movement in conjunction with the scraper and laser beam. A fuzzy control-based velocity optimization is proposed to avoid the shock effect on the imaging quality of the CMOS camera and the collision of the scraper and laser. The error between the current location and target location of the molten pool is utilized as the input of the fuzzy controller. Then, the parameters of the PI controller of the stepping motor are dynamically adjusted. ADAMS and SIMULINK co-simulation are conducted to verify the feasibility of the fuzzy algorithm. Finally, the experiment of collaborative motion and the responses of each module are conducted. The results show that with the proposed collaborative platform, the response speed of the system is improved by about 49.6%, and the initial speed of the motor is decreased by about 12.6%, thus avoiding excessive acceleration of the motor. The response time of each motor is ahead of schedule by about 31.8%, which meets the requirements of motion response for SLM process monitoring.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47034231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inclined colloidal drops: Evaporation kinetics and pattern formation 倾斜胶体滴:蒸发动力学和模式形成

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-04-25 DOI: 10.3389/fmech.2023.1086544

M. Parsa, Alexandros Askounis

{"title":"Inclined colloidal drops: Evaporation kinetics and pattern formation","authors":"M. Parsa, Alexandros Askounis","doi":"10.3389/fmech.2023.1086544","DOIUrl":"https://doi.org/10.3389/fmech.2023.1086544","url":null,"abstract":"The drying of solute-laden drops is ubiquitous in everyday life, from paints and printers to the raindrops drying on our windows. Nonetheless, scientific interest has primarily focused on understanding the evaporation kinetics on flat surface, with the key parameter of substrate inclination only recently started being addressed. This work focuses on the influence of moderate substrate inclinations at 20° and 40° on the evaporation kinetics and associated deposit patterns of colloidal drops. Inclination altered the shape of the drops which formed a lower contact angle at the upper side of the drop (rear edge) and larger contact angle at the lower side (front edge). As evaporation rate is a function of contact angle, which in turn is a function of inclination, the evaporation lifetime was extended by 43% and 61% for 20° and 40°, respectively, compared to a flat drop. A theoretical approximation of the evaporative flux across the liquid-vapour interface of the drops showed the contribution of each edge to the evaporation kinetics. These differences in the evaporative fluxes altered the internal flows within the drop and in turn the coffee-ring formation mechanism. The particle deposit shape at the two edges for each drop was visualised which combined with the theoretical arguments allowed the proposition of the particle deposition mechanism in inclined drops: inclination added a gravitationally-driven velocity flow component within the drops, which is perpendicular and hence negligible in flat drops. This additional flow hindered or enhanced the number of particles arriving at the rear and front edges of the inclined drops, respectively, and hence influenced the dimensions of the coffee-ring patterns. Eventually, the particle deposits grew sufficiently tall to effectively stagnate the outward flow which resulted in enhanced particle accumulation at the interior of the drops as inclination increased.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91225571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Wind-induced evaporative cooling passive system for tropical hot and humid climate 用于热带湿热气候的风致蒸发冷却被动系统

IF 4.5 2区工程技术

Frontiers of Mechanical Engineering Pub Date : 2023-04-19 DOI: 10.3389/fmech.2023.1069806

T. Moh, J. Jin, L. A. Wong, M. Tiong, C. Chan

{"title":"Wind-induced evaporative cooling passive system for tropical hot and humid climate","authors":"T. Moh, J. Jin, L. A. Wong, M. Tiong, C. Chan","doi":"10.3389/fmech.2023.1069806","DOIUrl":"https://doi.org/10.3389/fmech.2023.1069806","url":null,"abstract":"Over the years, the desire to have better thermal comfort in terms of living has been extensively discussed and is in high demand, especially in metropolitan cities. Alongside the desired outcomes, air conditioning facilities have been implemented, but they also bring negative consequences, such as a high energy bill and multi-dimensional environmental impacts. To counter these problems, a hybrid technique combining the evaporative cooling technique with a venturi-shaped natural ventilation tower is proposed. Evaporative cooling takes advantage of cooling in response to the wind blowing through a layer of wetted surface that is built with permeable materials. Combining with the specially designed venturi-shaped natural ventilation tower to improve the volume intake of wind externally, this system is aimed to reduce temperature and achieve thermal comfort by cooling down the air with circulation in a continuous accumulative mode. To gauge the efficiency and effectiveness of this hybrid technique, an evaporative system known as the wind-induced evaporative cooling (WIEC) system is directly fed into a testing chamber (installed with sensors) fabricated with a scale of 1:6. The system was tested in a hot and humid climate with a temperature range of 27°C–34°C. The finding shows that our system is able to reduce temperatures up to 3.873°C with an output cooling capacity of 9 W–476.3 W, which shows the feasibility of this study.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45425111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1