Mechanics & Industry最新文献_第3页

Physically-based modelling for sheet metal cone parts forming under blast loading 在爆炸载荷下成形的金属板锥件的物理建模

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021002

R. Alipour

引用次数: 3

Experimental and numerical investigation of geometric effect on cavitation flow through orifice 孔口空化流动几何效应的实验与数值研究

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021018

Mohammad Reza Davoudi, Miralam Mahdi

引用次数: 0

Variable flow and optimization of chiller loading effect on energy saving for screw vapor compression-single effect absorption hybrid chiller plant in hospital mechanical room ‒ case study: Tehran heart hospital 医院机械室螺杆式蒸汽压缩-单效吸收式混合冷水机组变流量及机组负荷优化对节能的影响——以德黑兰心脏医院为例

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021006

R. Boghosian, M. Mafi, M. H. Panjeshahi, A. Ataei

{"title":"Variable flow and optimization of chiller loading effect on energy saving for screw vapor compression-single effect absorption hybrid chiller plant in hospital mechanical room ‒ case study: Tehran heart hospital","authors":"R. Boghosian, M. Mafi, M. H. Panjeshahi, A. Ataei","doi":"10.1051/MECA/2021006","DOIUrl":"https://doi.org/10.1051/MECA/2021006","url":null,"abstract":"Chiller plants are the most energy consuming system during summer season in residential, commercial and hospital buildings. The highly variable cooling demand of the buildings connected to a hybrid chiller plant included absorption and vapor compression chillers to achieve higher energy efficiencies is one of the important issues. Cooling load sharing strategies and apply the variable water flow system in chiller plant have a significant impact on energy consumption and consequently with more productivity and environmentally protected. This paper examines the behavior and pattern of energy consumption in a hybrid chiller plant that includes a combination of two air-cooled screw vapor compression and three single effect absorption chillers. In order to properly understand the pattern of energy consumption, an existing mechanical room in a hospital in Tehran has been studied for five months, and its energy consumption has been compared with the optimized model. The results indicate that the sequence of the chiller function and the way in which they are placed in the circuit during a partial load, is in highest importance in view point of energy saving also by Applying of variable water flow system for optimized chiller loading the more energy saving is achieved for hybrid absorption and vapor compression chiller plant.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"84 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86572709","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}

引用次数: 1

Numerical investigation on the cooling performance of a novel jet cooler design for a supercritical CO2 turbine rotor shaft cooling 超临界CO2涡轮转子轴冷却新型射流冷却器冷却性能的数值研究

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/meca/2021049

Jun Li, H. Gurgenci, Jishun Li, Z. Guan, Lun Li, Y. Xue

{"title":"Numerical investigation on the cooling performance of a novel jet cooler design for a supercritical CO2 turbine rotor shaft cooling","authors":"Jun Li, H. Gurgenci, Jishun Li, Z. Guan, Lun Li, Y. Xue","doi":"10.1051/meca/2021049","DOIUrl":"https://doi.org/10.1051/meca/2021049","url":null,"abstract":"Numerical investigation was carried out to study the heat transfer performance for a high-speed rotating cylindrical surface subjected to single row array round jets impingement, under a very small gap spacing. Various parameters that affect heat transfer, such as the fluid density, flow velocity and Nusselt number distributions of the radius clearance were studied based on varied nozzle to target surface spacing H and mass flow rate. It has been found that the fluid density was a dominant factor and the velocity was the secondary factor for the gas jet heat transfer performances. The overall heat transfer was improved with a reduction in the number of nozzles, for given inlet mass flow rate boundary conditions. The decrease of H/di (di, nozzle diameter) may have positive or negative effects on the heat transfer performance from the impingement surface. Reducing the radius gap H, for a certainty, increases the average density of the fluid in the clearance, which is desirable in applications that enhance heat transfer performance. But when the radius gap (H) is small enough, increasing di may have a negative impact on heat transfer.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"47 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75739641","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}

引用次数: 0

Combination of oriented-plane curvature reproduction and squeeze film effect-based texture reproduction to simulate curved and textured surface 结合面向平面曲率再现和基于挤压膜效果的纹理再现，模拟曲面和纹理表面

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021024

Tao Zeng, Yan Liu, Enshan Ouyang

{"title":"Combination of oriented-plane curvature reproduction and squeeze film effect-based texture reproduction to simulate curved and textured surface","authors":"Tao Zeng, Yan Liu, Enshan Ouyang","doi":"10.1051/MECA/2021024","DOIUrl":"https://doi.org/10.1051/MECA/2021024","url":null,"abstract":"The finger skin contains a variety of receptors, which provide multiple tactile sensing channels. When a finger touches the surface of an object, people can simultaneously perceive curvature, texture, softness, temperature, and so on. However, in most of research activities, the designed haptic feedback devices can only focus on a certain channel. In this paper, the rendering of curved and periodic textured surfaces involving two channels, i.e., curvature and texture, was studied. Two psychophysical experiments were conducted to investigate whether the coupling of kinesthetic feedback of curvature and tactile feedback of texture could reproduce curved and textured surfaces with high fidelity. The results showed a deviation of the point of subjective equality values in terms of curvature and roughness, indicating that the curvature rendering and texture rendering have an impact on each other. Therefore, it is necessary to correct the bias when making virtual rendering. The influence of curvature on texture rendering is reduced by recalculating and adjusting the spatial period of the synthesized texture in real-time; the influence of texture on curvature rendering is eliminate by compensating the force difference between touch on physical strip and artificial stimulus.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"30 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76039215","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}

引用次数: 0

Dynamics modeling and analysis of feed drive system for a frame saw machine considering time-varying load 考虑时变载荷的框架锯床进给传动系统动力学建模与分析

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021019

Depeng Sun, Jinsheng Zhang

{"title":"Dynamics modeling and analysis of feed drive system for a frame saw machine considering time-varying load","authors":"Depeng Sun, Jinsheng Zhang","doi":"10.1051/MECA/2021019","DOIUrl":"https://doi.org/10.1051/MECA/2021019","url":null,"abstract":"Frame saw machine is one of machine tools that is used to process dimension stone. The velocity fluctuation of traditional feed drive system (FDS) lead to excessive wear of diamond particles. The dynamic performance of the FDS has time-varying characteristics during the processing of stone with a large material removal rate. In this paper, a novel FDS was proposed. Firstly, the dynamic modeling of FDS was set up on account of lumped parameter method (LPM). Then the speed of the new FDS was compared with that of the traditional FDS. Finally, the frequency response characteristics of the system were solved by Lagrange and state space method. Results showed that the new FDS has a faster response feed and less velocity fluctuation. The natural frequency and the amplitude of acceleration increase with decreasing load. With the time-varying load, the range of the second-order natural frequency increased by 50 Hz, which was larger than that of the first-order. The modal test verified that the first two natural frequencies of the saw blade are within the range of the natural frequencies of FDS. The proposed FDS can guide for design, reduce the wear of diamond, and improve processing quality.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"76 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77212806","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}

引用次数: 5

Aeroelastic scaling of flying demonstrator: flutter matching 飞行演示机气动弹性标度:颤振匹配

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/meca/2021041

J. Colomer, N. Bartoli, T. Lefebvre, J. Martins, J. Morlier

{"title":"Aeroelastic scaling of flying demonstrator: flutter matching","authors":"J. Colomer, N. Bartoli, T. Lefebvre, J. Martins, J. Morlier","doi":"10.1051/meca/2021041","DOIUrl":"https://doi.org/10.1051/meca/2021041","url":null,"abstract":"The traditional approach for the design of aeroelastically scaled models assumes that either there exists flow similarity between the full-size aircraft and the model, or that flow non-similarities have a negligible effect. However, when trying to reproduce the behavior of an airliner that flies at transonic conditions using a scaled model that flies at nearly-incompressible flow conditions, this assumption is no longer valid and both flutter speed and static aerodynamic loading are subject to large discrepancies. To address this issue, we present an optimization-based approach for wing planform design that matches the scaled flutter speeds and modes of the reference aircraft when the Mach number cannot be matched. This is achieved by minimizing the squared error between the full-size and scaled aerodynamic models. This method is validated using the Common Research Model wing at the reference aircraft Mach number. The error in flutter speed is computed using the same wing at model conditions, which are in the nearly-incompressible regime. Starting from the baseline wing, its planform is optimized to match the reference response despite different conditions, achieving a reduction of the error in the predicted flutter speed from 7.79% to 2.13%.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"7 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79021600","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}

引用次数: 2

Symmetry and asymmetry from MEMS variable capacitor by nonlinear micro stoppers 非线性微塞对MEMS可变电容的对称和不对称影响

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/meca/2021039

Jianxiong Zhu, Yunde Shi, Fengqin Ma

{"title":"Symmetry and asymmetry from MEMS variable capacitor by nonlinear micro stoppers","authors":"Jianxiong Zhu, Yunde Shi, Fengqin Ma","doi":"10.1051/meca/2021039","DOIUrl":"https://doi.org/10.1051/meca/2021039","url":null,"abstract":"Mechanical stoppers in MEMS capacitive systems can dramatically affect electrical performances and result in complicated mechanical dynamic responses. This paper introduces electromechanical coupling nonlinear dynamic responses in MEMS variable dual-capacitor with an effect of nonlinear and asymmetrical stoppers. We found that the capacitance in the electrical circuit system related to the first-order derivative of the output voltage on a load resistor, and the variable dual-capacitor was strongly affected by the coupling of up and down superposition instantaneous electrostatic force and limited space by the length of nonlinear stoppers. The numerical calculation results and the experimental results in our analysis based on our system had a good agreement, and the numerical simulation results presented rich nonlinear impacts dynamic responses through the imposed voltage and the height of stoppers in MEMS variable dual-capacitive device. The device in operation cannot reach the 0.6 time's initial gap due to small forcing amplitude (1.026 g). However, we observed that the movable plate and stoppers (across the 0.6 time's initial gap) had fierce impacts due to big forcing amplitude (4 g) on to the device. With asymmetric stopper each impact, we also concluded that the movable plate would experience attenuations of the displacement until the moment to the next impacts. Moreover, the height of stoppers can not only result in complicated dynamic motion of the movable plate, but also can modulate a voltage of the fixed plate with its asymmetry structure.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"53 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72955437","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}

引用次数: 2

Comparison of six gas turbine power cycle, a key to improve power plants 比较六种燃气轮机的动力循环，改进电厂的关键

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021005

A. Golneshan, H. Nemati

{"title":"Comparison of six gas turbine power cycle, a key to improve power plants","authors":"A. Golneshan, H. Nemati","doi":"10.1051/MECA/2021005","DOIUrl":"https://doi.org/10.1051/MECA/2021005","url":null,"abstract":"It is required to sake methods to improve the power plant performance. Most of the proposed methods can be commenced only in the design stapes. However, the main question of this study is “What can we do to improve the performance of a running power plant?” The first answer to this question is that monitoring the site and periodic overhaul can keep a power plant in its acceptable condition. However, this answer is very qualitatively and needs more precise information like which parameters shall be monitored or which equipment needs more care in the overhaul. In this study, important parameters and the method of their calculations are introduced that must be monitored and compared. Six similar gas turbine power cycles were selected to be compared deeply during a day in this study. In this way, many data were collected every five minutes. Unlike most of the previous studies, this one concerns with maintenance policy and repair strategy. Results of this comparison lead to answer to these questions that which equipment needs special care? Finally, it was shown that in each unit, which equipment needs more attention and which one can be considered as a standard for the others.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"40 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73967170","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}

引用次数: 1

Tooth bending stress analysis of high speed curve face gear of composite transmission 复合材料传动高速曲面齿轮齿面弯曲应力分析

IF 1.2 4区工程技术

Mechanics & Industry Pub Date : 2021-01-01 DOI: 10.1051/MECA/2021021

Yongquan Yu, Chao Lin, Yanan Hu

{"title":"Tooth bending stress analysis of high speed curve face gear of composite transmission","authors":"Yongquan Yu, Chao Lin, Yanan Hu","doi":"10.1051/MECA/2021021","DOIUrl":"https://doi.org/10.1051/MECA/2021021","url":null,"abstract":"To promote the engineering application of composite transmission of high speed curve face gear, which consists of a cylindrical gear and a high speed curve face gear, the analysis of tooth bending stress should be taken into consideration. High speed curve face gear pair is a new type of curve face gear pair. Combined with the principle of high speed cam and curve face gear pair transmission, it can transfer the axial/rotation composite motion and power between two intersecting shafts. Based on the gear engagement principle, the gear meshing coordinate system was established and the fundamental of the high speed composite transmission was expounded. Combined with the tooth profile equation of generating gear, the tooth surface equation of high speed curve face gear was gained. Tooth force, contact ratio and normal load distribution were calculated. Then the tooth bending stress of high speed curve face gear during the transmission was calculated and analyzed in detail. Influence of basic parameters on tooth bending stress was discussed. Finally, the simulation and measurement experiment of tooth bending stress was carried out. By the comparison analysis of simulation, experiment and theory, the correctness of tooth bending stress calculation method was verified, which has important guiding significance for the further research of high speed curve face gear of composite transmission.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":"23 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84351891","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}

引用次数: 3