International Journal of Computational Methods and Experimental Measurements最新文献_第8页

Numerical simulation of heat-loss compensated calorimeter 热损失补偿量热计的数值模拟

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-09-02 DOI: 10.2495/cmem-v7-n3-285-296

Yong-soo Choi, Kook Jin Jeon, Youngho Park, S. Hyun

引用次数: 2

Novel experimental setup to assess Surfaces in tribo-contact lubricated by the next generation of environmentally friendly thermofluids 新的实验设置，以评估摩擦接触润滑的下一代环境友好的热流体表面

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-09-02 DOI: 10.2495/CMEM-V7-N3-226-235

Muhammad Usman Bhutta, Z. Khan, Nigel P. Garland

{"title":"Novel experimental setup to assess Surfaces in tribo-contact lubricated by the next generation of environmentally friendly thermofluids","authors":"Muhammad Usman Bhutta, Z. Khan, Nigel P. Garland","doi":"10.2495/CMEM-V7-N3-226-235","DOIUrl":"https://doi.org/10.2495/CMEM-V7-N3-226-235","url":null,"abstract":"Environmental concerns related to global warming and ozone depletion triggered the introduction of the fourth generation of thermo-fluids. Amongst the recently introduced thermo-fluids, one of the most promising fourth generation of thermo-fluids are Hydrofluoroethers (HFEs). Hydrofluoroethers have zero ozone depletion potential and have a lower global warming potential as compared to widely used thermo-fluids. The type of thermo-fluid used in a thermodynamic cycle directly affects the tribological performance of the system. HFEs have been reported to have good thermodynamic properties. The overall tribological performance of Hydrofluoroethers however have to be investigated in detail in-order to fully assess the mechanical behaviour of interacting components utilizing these thermo-fluids. This study is concerned with the experimental test rig design modifications and commissioning to conduct tribological testing with HFEs as lubricants. This article covers the experimental test rig design and setup. Experiments to analyse the frictional force, the coefficient of friction and wear by using Hydrofluororther-7000 (HFE-347mcc3) as lubrication medium have been conducted. Industrial applications were simulated by varying test conditions and the results are presented in this paper.","PeriodicalId":36958,"journal":{"name":"International Journal of Computational Methods and Experimental Measurements","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85398602","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: 2

Development of a novel simulation code to predict three-dimensional neurogenesis by using multilayered cellular automaton 利用多层元胞自动机预测三维神经发生的新型模拟代码的开发

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-09-02 DOI: 10.2495/cmem-v7-n3-201-211

E. Nakamachi, Akie Nakayama, Takehiko Yamamoto, Y. Morita, H. Sakamoto

{"title":"Development of a novel simulation code to predict three-dimensional neurogenesis by using multilayered cellular automaton","authors":"E. Nakamachi, Akie Nakayama, Takehiko Yamamoto, Y. Morita, H. Sakamoto","doi":"10.2495/cmem-v7-n3-201-211","DOIUrl":"https://doi.org/10.2495/cmem-v7-n3-201-211","url":null,"abstract":"In this study, a novel simulation code to predict three-dimensional (3D) neurogenesis was developed by using a multilayered cellular automaton (CA) method. Recently, the induced pluripotent stem cell therapy treatments have rapidly grown up as an attractive repair and regeneration technologies for damaged central nervous system (CNS). However, understanding the repair mechanism and developing a numerical analysis code to predict CNS neurogenesis process have ultimate difficulties because more than hundreds of billions of neurons connect each other, and it is almost impossible to analyze the neurogenesis evolution process. Especially, the axonal extension to generate the neural network system is extremely difficult. In this study, based on the phase contrast microscopy (PCM) and the multiphoton microscope (MPM) observations of two-dimensional (2D) and 3D nerve cell network generation of the pheochromocytoma cells (PC12), a novel simulation code to predict the CNS morphogenesis was developed. At first, time-lapse PCM observations have been executed to understand the nerve cell axonal extension and branching. Secondly, 3D representative volume elements (RVEs) of cortex were derived by using Nissl-stained cerebral cortex images. Finally, a 3D CA simulation code for neurogenesis was developed based on multilayered CA algorithms, such as the dendrites outgrowth, an axon selection from dendrites, the extension enhancement induced by the nerve growth factor (NGF), and the branching caused by microtubule collapse under the effect of Netrin-1. Our newly developed CA simulation code was confirmed as a comprehensive code to predict neurogenesis processes through comparison with PCM and MPM observation results.","PeriodicalId":36958,"journal":{"name":"International Journal of Computational Methods and Experimental Measurements","volume":"110 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89181270","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

aerodynamic study of moto rcycle racing wheels: A performance evaluation based on numerical CFD simulations 摩托车赛车车轮气动研究:基于数值CFD模拟的性能评估

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-09-02 DOI: 10.2495/cmem-v7-n3-275-284

F. Concli, M. Gobbi, C. Gorla

{"title":"aerodynamic study of moto rcycle racing wheels: A performance evaluation based on numerical CFD simulations","authors":"F. Concli, M. Gobbi, C. Gorla","doi":"10.2495/cmem-v7-n3-275-284","DOIUrl":"https://doi.org/10.2495/cmem-v7-n3-275-284","url":null,"abstract":"In any racing competitions, the aerodynamic performances of the equipment are determinant. This is true, for example, for cars, where the geometry of the bodywork and of the wings can ensure a lower Cx coefficient and/or a higher down-force and a higher handling. In other competitions, like rowing, the aerodynamics of the hull can reduce the effort done by the athletes. In the cycle and motorcycle racing competitions, other aspects related to aerodynamics become important, such as the manoeuvrability and stability. In the present research, a numerical approach was used in order to compare different front-wheel geometries (of a racing motor-bike) in terms of drag, lift and axial forces. Three different wheel designs have been compared. The first one consists in a traditional seven spokes aluminium design, the second wheel is a 6 spokes magnesium solution and the third a solid-disk wheel. Steady state as well as transient simulations was performed with OpenfOaM®, a free open-source software. This was selected because it allows a higher flexibility with respect to any close-source commercial software. The possibility to customize the solver as well as the boundary conditions allows the analysis of the physical problem of interest. The free license allows a high parallelization of the computations. The steady-state simulations were performed by freezing the wheel position and introducing a rotating reference frame. In this way, the computational time was significantly reduced. for the transient simulations, the computational domain was split into two subdomains. The internal one is cylindrical and contains the wheel. The rotational velocity of the wheel was imposed by applying a rigid rotation to the mesh of the internal subdomain. Mesh interfaces ensures the continuity of the solution across the domains.","PeriodicalId":36958,"journal":{"name":"International Journal of Computational Methods and Experimental Measurements","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72748272","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

Novel thermal insulation with gas-filled cavities – assessment of thermal performance of different designs based on numerical simulations of heat transfer 新型充气腔绝热材料——基于传热数值模拟的不同设计的热性能评估

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-03-31 DOI: 10.2495/CMEM-V7-N2-181-192

Miha Jukić, S. Jordan, Danijel Lisičić

{"title":"Novel thermal insulation with gas-filled cavities – assessment of thermal performance of different designs based on numerical simulations of heat transfer","authors":"Miha Jukić, S. Jordan, Danijel Lisičić","doi":"10.2495/CMEM-V7-N2-181-192","DOIUrl":"https://doi.org/10.2495/CMEM-V7-N2-181-192","url":null,"abstract":"Not only is the energy efficiency of buildings nowadays becoming more and more important; the legislative requirements, the people’s awareness of the environmental questions and their thermal comfort expectations are also on a much higher level. all of these issues can be addressed by making the building envelope more thermally resistant. however, with the traditional thermal insulation materials the thickness of thermal insulation layers is already at the viable limits. Therefore, the development of new, more efficient thermal insulation products with a higher thermal resistance is highly promoted. Preliminary research results can be applied to models to develop and confirm the conceptual designs of such new materials. In this paper, an analysis of thermal performance is presented for a novel thermal insulation consisting of graphite polystyrene (gPS) matrix with cavities filled with an insulative gas, and a protective sheath to prevent it from leaking. bearing in mind the suitability for later production, different configurations of the assembly were considered, regarding the matrix geometry, the type of the gas filling, and the surface emissivity of the cavities. a range of numerical simulations of heat transfer was conducted to determine the efficiency of different designs in reducing the conductive, the convective, and the radiative heat transfer. advantages, limitations and some detailed parameters of the proposed design concepts were determined, which were then used for optimisation. The analysis of the results indicates that the equivalent thermal conductance of a gPS panel can be significantly reduced by the introduction of gas-filled cavities. The reduction is highly dependent on the type of the gas filling (thermal conductivity, viscosity, specific heat, etc.), the size of the cavities, and the cavity surface emissivity.","PeriodicalId":36958,"journal":{"name":"International Journal of Computational Methods and Experimental Measurements","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90158315","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: 1

A study of the viscous optimization of the shape of a non-lifting strut 非提升支杆形状的粘性优化研究

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-03-31 DOI: 10.2495/CMEM-V7-N2-93-105

R. Derksen, J. Veenendaal

引用次数: 0

Effective material properties of wood based on homogenization 基于均质化的木材有效材料特性

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-03-31 DOI: 10.2495/CMEM-V7-N2-167-180

M. Šejnoha, Lucie Kucíková, J. Vorel, Jan Sýkora, W. P. Wilde

引用次数: 3

Optimization of high-performance concrete post-tensioned box-girder pedestrian bridges 高性能混凝土后张箱梁人行桥的优化设计

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-03-31 DOI: 10.2495/CMEM-V7-N2-118-129

V. Yepes, Eloy Pérez-López, T. García-Segura, Julián Alcalá

引用次数: 3

Modelling of hydrocarbon gas and liquid leaks from pressurized process systems 烃类气体和液体从加压过程系统泄漏的建模

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-03-31 DOI: 10.2495/CMEM-V7-N2-154-166

Anand N Bahuguni, A. Kumara, K. Giljarhus

引用次数: 0

The influence of finite rupture times on flow dynamics within micro-shock tubes 有限破裂时间对微激波管内流动动力学的影响

International Journal of Computational Methods and Experimental Measurements Pub Date : 2019-03-31 DOI: 10.2495/CMEM-V7-N2-106-117

D. Adair, Abilkaiyr Mukhambetiyar, M. Jaeger, M. Malin

{"title":"The influence of finite rupture times on flow dynamics within micro-shock tubes","authors":"D. Adair, Abilkaiyr Mukhambetiyar, M. Jaeger, M. Malin","doi":"10.2495/CMEM-V7-N2-106-117","DOIUrl":"https://doi.org/10.2495/CMEM-V7-N2-106-117","url":null,"abstract":"The importance of micro-shock tubes is growing in line with recent developments of microscale technology for products like micro-heat engines and micro-propulsion systems. The flow dynamics within a micro-shock tube are different from those found in a macro shock tube, and knowledge of these dynamics is not as yet well established, as the flow within these tubes includes extra physics namely rarefaction and complex effects due to viscosity. Studies have recently been made with assumed initial condition of instantaneous diaphragm rupture producing centred shock and expansion waves. However, for a real case, the diaphragm ruptures over a finite time causing a period of partial rupture and this will change the shock characteristics. The work here reports on a series of axisymmetric numerical simulations carried out to calculate the influence of an initial finite-time diaphragm rupture. Rarefaction effects were taken into account by the use of Maxwell’s slip velocity and temperature conditions. Use of an initial finite-time diaphragm rupture boundary condition causes the forming of a non-centred shock wave downstream of the diaphragm, and, the shock propagation distance is considerably reduced by use of the finite-time rupture process.","PeriodicalId":36958,"journal":{"name":"International Journal of Computational Methods and Experimental Measurements","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89963326","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