检索结果-南通市图书馆

Comparative Heat Transfer Data for Solid-Liquid Phase Change of D-Mannitol and Adipic Acid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and Power Engineering 2022年第11期14卷 680-704页

作者： Ulyana Horbatyuk Ana Magalhães Victor Ferreira Carlos Pinho CEFT DEMEC Faculty of Engineering University of Porto Porto Portugal

The goal of this work was to measure the heat transfer rates from thermofluid, Therminol 66, to two phase change materials, D-mannitol and adipic acid. It concerns the determination of heat transfer coefficients for the design of a concentrated solar energy plant requiring PCM thermal energy storage and is part of a wider set of experiments, where several PCMs were tested. An experimental installation was used with a cylindrical vessel with three tubes disposed almost horizontally (5°inclination), containing the phase change material, around which the thermal fluid flowed almost perpendicular to the tubes. The experimental installation allowed to recreate heating and cooling cycles. In order to evaluate the influence of the flow on the rate at which the heating and cooling processes took place, tests were performed at different thermofluid mass flow rates, concluding that there is no great influence, since the thermal resistance inside the tubes is much higher than on the outside. D-mannitol and adipic acid, present different phase change temperatures, 164°C for D-mannitol and 152°C for adipic acid. The average heat transfer coefficient, during the phase change process, was of 340 W/(m2K) for D-mannitol and 1320 W/(m2K) for adipic acid.

关键词： Adipic Acid D-Mannitol Heat Transfer Coefficient Phase Change Materials

Experimental Study of Soot Volume Fraction Applied in Laminar Diffusion Flames

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modern Mechanical Engineering 2013年第4期3卷 137-141页

作者： N. R. Caetano F. M. Pereira H. A. Vielmo F. T. van der Lann Federal University of Rio Grande do Sul DEMEC-UFRGS Porto Alegre Brazil

The soot emission has been the focus of many studies due to applications in industry and the prejudicial effects caused to the environment. The presence of soot is important to the heat transfer in boilers and combustion chambers, contributing significantly to efficiency increases. In controversy, the inhaled soot may cause respiratory system damage and even cancer. Another important point is the contribution to the greenhouse effect. Therefore, the aim of this work is to analyse the soot emission in laminar diffusion flames produced from commercial fuels stabilized on a burner representative of industrial applications. Methane, vehicular natural gas and liquid petroleum gas are considered as fuels. An experimental setup was constructed to implement the technique of laser light extinction and laser-induced incandescence. These non-intrusive techniques provide instant information, in real time, about soot volume fraction. The measurements were calibrated and validated using methods and results of studies available in the literature, and also the uncertainty is analysed and suitably minimized. The results will contribute to the database for projects of combustion systems optimization, aiming to increase the efficiency and soot emissions control.

关键词： Soot Emissions Laminar Diffusion Flames Commercial Fuels

Periodic oscillations and stability of thin variable stiffness composite laminated plates

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Periodic oscillations and stability of thin variable stiffne...

Experimental and CFD Simulations of Pressure Loss through Perforated Plates

23rd International Congress of Theoretical and Applied Mechanics

作者： Pedro Ribeiro Hamed Akhavan demec/IDMEC Faculdade de Engenharia da Universidade do PortoPortoPortugal

＜正＞Tow placement machines allow for the variation of the orientation of fibres along a lamina and in this way one obtains a composite laminated panel where the stiffness varies from point to point. Forced,geometrically non-linear,periodic vibrations of thin variable stiffness composite laminated（VSCL） plates are analysed in

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Energy and Power Engineering 2011年第2期5卷 112-121页

作者： J.A. Barros Filho M.A. Navarro A. dos Santos E. Jordao Brazilian Nuclear Energy Commission （CNEN/CDTN） Av. Pres. Antonio Carlos 6627-UFMG-Pampulha 30123-970 Belo Horizonte Minas Gerais Brazil Federal University of Minas Gerais （UFA4G/DEMEC） Av. Pres. Antonio Carlos 662-UFMG-Pampulha 31270-901 Belo Horizonte Minas Gerais Brazil FEQ/UNICAMP Cidade Universitoria ＂Zeferino Vaz＂ Av. Albert Einstein 500 13083-852 Campinas SP Brazil

This paper presents the experimental pressure loss of water flow through perforated plates with geometry similar to the ones of the bottom end piece of a Pressurized Water Reactors （PWR） fuel element. Geometric features like the number, pattern and diameter of holes were evaluated as well as different inlet chamfers. The recovering pressure profile downstream of the plates was also measured. The experimental results were compared with numerical modeling performed with the commercial Computational Fluid Dynamics （CFD） code CFX 11.0. The analysis of the results shows that the standard k-e turbulence model presents the best compromise between computing time and accuracy for the calculation of the total pressure loss through the perforated plates tested.

关键词： Computational fluid dynamics (CFD) pressurized water reactors-PWR pressure drop perforated plates