Defect and Diffusion Forum最新文献_第5页

Study on Two-Phase Pressure Drop of Methane during Flow Boiling in Mini Channel 小型通道中甲烷流动沸腾过程中的两相压降研究

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-3yYkrV

Jie Song, Qing Lian Li, Jun Sun, Xin Lin Liu, Lan Wei Chen

{"title":"Study on Two-Phase Pressure Drop of Methane during Flow Boiling in Mini Channel","authors":"Jie Song, Qing Lian Li, Jun Sun, Xin Lin Liu, Lan Wei Chen","doi":"10.4028/p-3yYkrV","DOIUrl":"https://doi.org/10.4028/p-3yYkrV","url":null,"abstract":"For LOX/LCH4 variable thrust rocket engine, the propellant methane is traditionally selected as the coolant in regenerative cooling channel (RCC). With the decrease of engine thrust, the mass flow rate of coolant methane decreases gradually. At low engine thrust, the coolant methane is usually in a subcritical state. The heat transfer deterioration of subcritical methane occurs in RCC, which may cause thrust chamber wall ablation. The two-phase pressure drop data of methane are crucial parameters for the design and optimization of RCC. But it is rarely to find such measured frictional pressure drop data of methane in open published literature. The two-phase pressure drop of methane during flow boiling in the single mini channels with the diameters of 2.0 mm are investigated systematically. Effects of the mass flux (582.19~1755.48 kg/m2·s), inlet pressure (0.56~3.55 MPa), heat flux (53.25~318.68 kW/m2) on the frictional pressure drop of methane are discussed. The results show that the frictional pressure drop of methane during flow boiling increases with mass flux and inlet pressure at the experimental conditions, and heat flux shows weak effect on the frictional pressure drop. The comparisons of the experimental data with the predicted value by existing six correlations are analyzed. Contrary to the conventional channels, homogeneous model yields better prediction than five separated flow models. Present experimental results can provide reference for the design and optimization of RCC in LOX/LCH4 rocket engine.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"32 1","pages":"229 - 238"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139009557","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

Experiments on Hydrogen Uptake and Diffusion in LiNb0.15Ta0.85O3 Single Crystals by Infra-Red Spectroscopy 用红外光谱法研究 LiNb0.15Ta0.85O3 单晶中的氢吸收和扩散实验

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-2J7FpE

C. Kofahl, Steffen Ganschow, Harald Schmidt

引用次数: 0

Contribution to the Improvement of the Wear Resistance of the AISI 1010 Material by the Tribofinishing Process Using the Box-Behnken Experimental Designs 采用箱式贝肯实验设计的三精加工工艺对提高 AISI 1010 材料耐磨性的贡献

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-W1ujm5

D. Saidi, M.A. Djema, K. Hamouda, S. Abdi, M. Bouaziz

{"title":"Contribution to the Improvement of the Wear Resistance of the AISI 1010 Material by the Tribofinishing Process Using the Box-Behnken Experimental Designs","authors":"D. Saidi, M.A. Djema, K. Hamouda, S. Abdi, M. Bouaziz","doi":"10.4028/p-W1ujm5","DOIUrl":"https://doi.org/10.4028/p-W1ujm5","url":null,"abstract":"Tribofinishing is a mechanical-chemical process that utilizes low-frequency vibrations in the presence of abrasives and chemical additives. This process is primarily dependent on frequency and amplitude, which generally leads to improvements in characteristics, mechanical properties, physical attributes, and metallography of the treated surfaces. This document examines the influence of abrasives, specifically bakelites used as unguided cutting tools, on the wear resistance of AISI 1010 carbon steel. It takes into account the variation of influential parameters, namely frequency, amplitude, and treatment duration. The use of Minitab version 16 software enabled us to statistically analyze and interpret the obtained results, both numerically and graphically. This analysis also allowed us to determine the order and degree of influence of the factors on the response. The obtained results are highly interesting. The coefficient of friction decreased significantly with an increase in the treatment time, up to 90 minutes, while maintaining a frequency of up to 90 Hz and a maximum amplitude of 5 mm.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"3 11","pages":"127 - 135"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139007723","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

Optimizing Diffusion Time and other Resources by Using the Diffusion Rate and Number of Stages Concepts 利用扩散率和阶段数概念优化扩散时间和其他资源

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-s1EZrY

F. E. Carvajal-Larenas

{"title":"Optimizing Diffusion Time and other Resources by Using the Diffusion Rate and Number of Stages Concepts","authors":"F. E. Carvajal-Larenas","doi":"10.4028/p-s1EZrY","DOIUrl":"https://doi.org/10.4028/p-s1EZrY","url":null,"abstract":"Considering that velocity of diffusion in a system solute-porous material-solvent depends on several factors, (among them, the concentration differential between “solute” in the porous material and “solute” in the solvent) the diffusion process will finish only when maximum entropy is achieved. Thus, the solute concentration will be equal in the matrix and in the solvent (equilibrium concept). On the other hand, if the velocity of diffusion depends on the differential of concentration, then, the amount of materials transferred per time unit (diffusion rate) will diminish as the process goes on. Moreover, when the final concentration of solute in the porous material is desired to be lower than that of the one-stage-equilibrium, then n-more stages must be added. Thus, the decision to choose a process with one or more stages, as well as the end point in each stage (as close or as far as equilibrium) will determine processing time and the use of other resources, i.e. amount of solvent, installation size, financial investment and so on. Therefore, the objective of this study is to develop a tool that helps to optimize these decisions by using a numerical approach.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"6 4","pages":"3 - 12"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139008749","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

CFD Analysis of Perforated Plates and Open-Cell Materials Aerodynamics 穿孔板和开孔材料空气动力学 CFD 分析

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-O0aFG5

Antonio F. Miguel

引用次数: 0

Astrophysics of X-Ray Binary Spectra X 射线双星光谱天体物理学

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-Sp3C6x

Leticia Corral Bustamante

{"title":"Astrophysics of X-Ray Binary Spectra","authors":"Leticia Corral Bustamante","doi":"10.4028/p-Sp3C6x","DOIUrl":"https://doi.org/10.4028/p-Sp3C6x","url":null,"abstract":"In view of the fact that X-ray sources present characteristic spectra that make them unique, the spectral fitting technique has proven to play a fundamental role through the use of models that make it possible to reproduce the observed spectrum, thus making it possible to characterize the type of source that gave rise to it. A tool of paramount importance, among others that are currently gaining ground, is the XSPEC software, which is a solid and stable spectral fitting package that allows us to conduct scientific work with high standards of rigor in the analysis of data from astronomical objects in whose processes high energies are intrinsically involved, as is the case of X-rays. In this work we fit and analyze experimental data of two X-ray binary spectra: Cyg X-1 and V 0332+53, with theoretical models in XSPEC to obtain the expected statistics of the best fit through the reduced chi-square (hereafter, χ2) in both astronomical sources. From the results, it can be concluded that in both sources the best fit representing the physical processes occurring in these binaries was achieved, very close to results obtained by other authors using different techniques, contributing to the state of the art of the spectrum of astrophysical processes of high energy binaries.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"13 4","pages":"45 - 70"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139009795","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

Drying of Industrial Sanitary Ware at Low Temperature: A Theoretical and Experimental Investigation 工业卫生洁具的低温干燥：理论与实验研究

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-Ghg2E8

Ricardo Soares Gomez, Kelly C. Gomes, José Maurício Alves de Matos Gurgel, Fabio Emanuel França da Silva, Laís Belizário Alves, Hortência Luma Fernandes Magalhães, A.G. Barbosa de Lima

{"title":"Drying of Industrial Sanitary Ware at Low Temperature: A Theoretical and Experimental Investigation","authors":"Ricardo Soares Gomez, Kelly C. Gomes, José Maurício Alves de Matos Gurgel, Fabio Emanuel França da Silva, Laís Belizário Alves, Hortência Luma Fernandes Magalhães, A.G. Barbosa de Lima","doi":"10.4028/p-Ghg2E8","DOIUrl":"https://doi.org/10.4028/p-Ghg2E8","url":null,"abstract":"Sanitary ware, including toilets, washbasins, and bathtub, plays a crucial role in maintaining hygiene and sanitation in various settings. The drying process is a critical stage in the manufacturing of ceramic sanitary ware, as it influences product quality, production efficiency, and energy consumption. Then, the purpose of this work is to investigate the drying of sanitary ware at low temperature by experiments and empirical mathematical models. The idea is to accurately predict moisture loss of the ceramic parts under different operational conditions. Results of the drying kinetics have shown that higher temperatures and lower air relative humidity accelerate the drying process. Also, no cracks or fissures were observed as a result of drying sanitary ware at low temperatures and the two-term model provides the best fit for the dimensionless average moisture content as a function of the time. These findings contribute to a better understanding of the drying process and support the optimization of sanitary ware manufacturing.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"44 23","pages":"152 - 161"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139007129","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

Advances in Mass and Thermal Transport in Engineering Materials IV 工程材料中质量和热传输的进展 IV

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/b-bh2nvw

Andreas Öchsner, G. Murch, I. Belova

引用次数: 0

Statistical Model of Hydrogen Diffusion in BCC Metals BCC 金属中氢扩散的统计模型

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-rbcq6Z

Serhii Bobyr, J. Odqvist

引用次数: 0

Copper, Iron and Aluminium Electrochemical Corrosion Investigation during Electrolysis and Temperature Increasing 电解和升温过程中铜、铁和铝的电化学腐蚀研究

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-5pUGB3

M. Yarmolenko, Sergii O. Mogilei

{"title":"Copper, Iron and Aluminium Electrochemical Corrosion Investigation during Electrolysis and Temperature Increasing","authors":"M. Yarmolenko, Sergii O. Mogilei","doi":"10.4028/p-5pUGB3","DOIUrl":"https://doi.org/10.4028/p-5pUGB3","url":null,"abstract":"An experimental method to calculate average charge of metal ions by electrolysis at different temperatures is proposed. Aluminium undergoes dissolution to the Al3+ ions at all temperatures. Iron undergoes dissolution to the Fe2+ or the Fe3+ ions and copper undergoes dissolution to the Cu+ or the Cu2+. It depends on temperature and electric current density. Direct electric current value and anode mass decreasing were measured during electrolysis into concentrated NaCl solution in water (5 mol/kg or 23.1%, freezing point equals -22°C, pH 6.5–7.5) at room temperature and 100°C. The average charges of copper, iron, and aluminium ions were calculated using Faraday’s law of electrolysis at electric current density 3,000 A/m2 (or 30 A/dm2): +3 for aluminium; +2 for iron; and +1 for copper at room temperature, and +3 for aluminium; +2 for iron; and +1.5 for copper at temperature 100°C. The main condition was zAl=3. We concluded that calculations of the average metal ions charges, zFe and zCu, were correct since zAl=3. The result is as follows: the Al3+, the Fe2+, and the Cu+ ions dissolve into concentrated NaCl solution in water at room temperature; the Al3+, the Fe2+, the Cu+ and the Cu2+ ions (50%/50%) dissolve into the solution at temperature 100°C. We have obtained experimentally and by mathematical modelling that aluminium anodes (cylindrical or spherical) dissolve into the solution more rapidly with temperature increasing during electrolysis accordingly to the Arrhenius law, while copper anodes (cylindrical or spherical) dissolve more slowly with temperature increasing from room temperature to temperature 180°C like “inverse Arrhenius law”. Iron electrochemical corrosion rate practically does not depend on temperature below 100°C (and, obviously, up to 180°C) like “zeroth Arrhenius law”. The spherical anode effect is greater than the cylindrical anode effect in 1.5 times.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"43 24","pages":"93 - 106"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139007744","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