检索结果-内蒙古大学图书馆

Constructing a ghost fluid layer for implementation of contact angle schemes in multiphase pseudopotential lattice Boltzmann simulations for non-isothermal phase-change heat transfer

引用

INTERNATIONAL JOURNAL OF heat AND MASS transfer 2023年 201卷

作者： Wang, Dongmin Cheng, Ping Univ Shanghai Sci & Technol Sch Energy & Power Engn Key Lab Multiphase Flow & Heat Transfer Shanghai P Shanghai 200093 Peoples R China Shanghai Jiao Tong Univ Sch Mech Engn Shanghai 200240 Peoples R China Suzhou Univ Sci & Technol Jiangsu Key Lab Micro & Nano Heat Fluid Flow Techn Suzhou 215009 Peoples R China

The PP scheme (primitive pseudopotential-based scheme), the MP scheme (modified pseudopotential-based scheme) and the IVD scheme (improved virtual-density scheme) are the three most widely used contact angle schemes in pseudopotential lattice Boltzmann (LB) models to simulate wetting character-istics of multiphase flow over solid surfaces under isothermal conditions. In this paper, we apply these schemes to simulate the problem of sessile droplet evaporation on a heated substrate, which is an ex-ample of non-isothermal phase-change heat transfer process. It is found that the substrate heating effect destabilizes algorithms of these schemes in certain ranges of contact angles of a heated substrate. The droplet interface shapes simulated by the PP scheme and the MP scheme are inaccurate at obtuse con-tact angles due to large fluid density variations near the wall. The spurious currents near the droplet triple-phase contact line are very large in the MP scheme, causing the deformation of the Marangoni vortex shape inside the droplet and the erroneous droplet interface temperature distribution near the triple-phase contact line. The addition of a special ghost fluid layer on the wall proposed in this study can improve numerical stability of the PP and the MP schemes for application under non-isothermal conditions as well as under high saturated liquid/vapor density ratios. Although the IVD Scheme (with the nearest fluid layer temperatures above the heated wall chosen for calculating the effective mass of wall nodes) is also stable at low liquid/vapor density ratios, its numerical stability at high density ra-tios is not as robust as those of the PP and the MP schemes if a special ghost fluid layer is added in these schemes. It is shown that by adding such a special ghost fluid layer on the wall, large near-wall fluid density variations diminish in the PP and MP schemes and accurate droplet interface shapes can be recovered at obtuse contact angles. The spurious current

关键词： Pseudopotential lattice Boltzmann model Droplet evaporation Contact angle scheme

来源：评论

学校读者我要写书评

暂无评论

Resistance characteristics analysis of droplet logic gate based on lattice Boltzmann method

引用

EUROPEAN JOURNAL OF MECHANICS B-FLUIDS 2021年 86卷 90-106页

作者： Yang, Fan Shao, Xusheng Wang, Ying Lu, Yuansheng Cai, Xiaoshu Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Univ Shanghai Sci & Technol Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Univ Queensland Sch Mech & Min Engn St Lucia Qld 4072 Australia

In this paper, the geometric models of microfluidics NON-AND and AND-OR droplet logic gate devices are designed, and the operations of NON-AND and AND-OR logic are implemented in the designed models. Based on the color-gradient model (R-K model) of lattice Boltzmann method (LBM), the two-phase flow pattern in microchannel is simulated. Based on the "equivalent length method", the Laplace resistance at the droplet phase interface and the local resistance at the right-angle bend are equivalent to the additional pipe length required for continuous phase flow in the channel to generate the same on-way resistance increment, and the resistance characteristics when slug flow droplets exist in the microchannel are quantitatively analyzed. The method is further applied to the analysis of the resistance characteristics of the droplet logic gate, and the quantitative explanation of the droplet path-choosing behavior is obtained. Compared with the "hydroelectricity analogism method", the "equivalent length method" is more concise and easy to understand. The research results in this paper provide theoretical basis for the design of other forms of droplet logic gate devices. (C) 2020 Elsevier Masson SAS. All rights reserved.

关键词： Droplet logic gate Analysis of resistance characteristics Lattice Boltzmann method Color-gradient model Equivalent length method

来源：评论

学校读者我要写书评

暂无评论

Editorial: multiphase flow in energy studies and applications—A special issue for MTCUE-2022

引用

Physics of Fluids 2023年第7期35卷 1-7页

作者： Zhu, Li-Tao Xu, Fei Jin, Hui Xiong, Qingang Department of Chemical and Biological Engineering University of British Columbia VancouverBCV6T 1Z3 Canada School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai200240 China Electronics Business Unit Ansys Inc. AustinTX78746 United States State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China State Key Laboratory of Pulp and Paper Engineering South China University of Technology Guangzhou510641 China

Establishing a clean, low-carbon, and efficient energy system is paramount for the sustainable development of industries and human society. multiphase flows are encountered extensively in various energy applications, including transportation, conversion, and utilization of fossil, renewable, hydrogen, and nuclear energies. These flows encompass a wide range of phenomena, such as fluid flow, heat and mass transfer, combustion, and chemical reactions. However, multiphase flows are highly intricate due to the coexistence of multiple phases, states, and components, as well as the interactions among them that occur across diverse spatiotemporal scales. Consequently, both academia and industry face significant challenges in comprehending and harnessing multiphase flows. Thus, establishing connections between basic research and industrial applications in the field of multiphase flows is fundamental and indispensable for advancements in energy science and technologies. © 2023 Author(s).

关键词： multiphase flow

来源：评论

学校读者我要写书评

暂无评论

A Demonstration of Broadband Cavity-Enhanced Absorption Spectroscopy at Deep-Ultraviolet Wavelengths: Application to Sensitive Real-Time Detection of the Aromatic Pollutants Benzene, Toluene, and Xylene

引用

ANALYTICAL CHEMISTRY 2022年第10期94卷 4286-4293页

作者： Wang, Meng Varma, Ravi Venables, Dean S. Zhou, Wu Chen, Jun Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Natl Inst Technol Calicut Dept Phys Calicut 673601 Kerala India Univ Coll Cork Sch Chem Cork T12 K8AF Ireland Univ Coll Cork Environm Res Inst Cork T12 K8AF Ireland

Benzene, toluene, and xylene (BTX) are serious air pollutants emitted by the chemical industry. Real-time monitoring of these air pollutants would be a valuable tool to regulate emissions of these compounds and reduce the harm they cause to human health. Here, we demonstrate the first detection of BTX using incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS). The instrument was operated in the deep- ultraviolet spectral region between 252 and 286 nm, where aromatic compounds have intense pi-pi* absorption bands. The mirror reflectivity was calibrated by two methods and exceeded 99.63% at 266 nm. At an integration time of 60 s, the 1 sigma measurement sensitivities were estimated to be 7.2 ppbv for benzene, 21.9 ppbv for toluene, 10.2 ppbv for m-xylene, and 4.8 ppbv for p-xylene, respectively. The absorption cross sections of BTX were measured in this work with an uncertainty of 10.0% at a resolution of 0.74 nm. The absorption cross sections reported in this work were in good agreement with those from earlier studies after accounting for differences in spectral resolution. To demonstrate the ability of the instrument to quantify complex mixtures, the concentrations of m-xylene and p-xylene have been retrieved under five different mixing ratios. Instrumental improvements and measurements strategies for use in different applications are discussed.

关键词： Toluene Absorption spectroscopy Benzene Xylene

来源：评论

学校读者我要写书评

暂无评论

Improvement and experimental study of scroll expander for organic rankine cycle

引用

Energy engineering: Journal of the Association of Energy engineering 2020年第4期117卷 225-235页

作者： Li, Lei Tao, Leren Gou, Yanan Zhang, Shan Zaozhuang University Zaozhuang277160 China University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China

The scroll expander used in organic Rankine cycle (ORC) system is improved, and its performance is analyzed experimentally. The modified profile and inlet hole of the scroll expander are enhanced, and the performance of the scroll expander before and after the improvement is analyzed. The results show that when the inlet pressure exceeds 0.7 MPa, the waist-shaped hole with a larger area is preferable. The scroll expander with a waist-shaped hole has a larger output power and wider optimal pressure range, and when the inlet pressure is 1.6 MPa, the maximum output power increases by 230 W. The output power and isentropic efficiency of the scroll expander can be improved by modifying the profile. When the inlet pressure is 1.6 MPa and the rotational speed is 1750 r/min, the maximum output power of the scroll expander is 1235 W, which is 120 W higher than that before the improvement. © 2020, Tech Science Press. All rights reserved.

关键词： Rankine cycle

来源：评论

学校读者我要写书评

暂无评论

The investigation of SrCoO3-6 perovskite doping cobalt oxide thermochemical energy storage system

引用

JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS 2022年第0期136卷

作者： Wang, Boyan Wang, Zhiyuan Dou, Binlin Ma, Yan Liang, Yijing Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China

Background: The current research of doping for metal oxide thermochemical energy storage (TCES) systems mainly focuses on the mutual doping among traditional metal oxides. However, it is too one-sided to solve the problem. In this work, SrCoO3-6 perovskite material is novelly doped into the cobalt oxide material system to solve the dehiscent problem of honeycombs, while compensating the energy storage density of materials system. Methods: Simultaneous thermal analysis (STA) is used to assess energy storage density, reaction kinetics, stability of materials. Thermo-mechanical stability assessment and thermal expansion tests are conducted to analyze the anti-crack performance of honeycombs. XRD, SEM, and XPS methods are used to analyze the characteristics of materials. Significant findings: The mass ratio of doping of 30% exhibits the best comprehensive performance. Based on this, the attenuation of energy storage density of SrCoO3-6 doping is narrowed from 27.1% to 22.9% at least compared with Al2O3 doping for anti-crack, and SrCoO3-6 doping has no negative effects on reaction kinetics of original cobalt oxide and a better stability. Beyond that, the SrCoO3-6 doping method of this work exhibits a better balance among various performance indicators of TCES than traditional doping methods based on improving TCES performance. Superscript/Subscript Available

关键词： Thermochemical energy storage Cobalt oxide Perovskite Doping

来源：评论

学校读者我要写书评

暂无评论

Experimental investigation on the ethane pulsating heat pipe under asymmetric heating

引用

APPLIED THERMAL engineering 2023年第1期229卷

作者： Zhan, Jingru Chen, Xi Ji, Yuzhe Zhang, Hua Univ Shanghai Sci & Technol Sch Energy & Power Engn 516 Jungong Rd Shanghai 200093 Peoples R China Univ Shanghai Sci & Technol Shanghai Key Lab Multiphase Flow & Heat Transfer P 516 Jungong Rd Shanghai 200093 Peoples R China

A three-dimensional cylindrical copper pulsating heat pipe (PHP) with ethane as the working fluid is designed. Experiments are conducted to study the thermal performance of the ethane PHP under the asymmetric heating mode. The evaporation section is divided into two parts: the left part and the right part. The left and right evaporators are provided with different heat inputs to study the temperature oscillation and heat transfer performance. Three cases are carefully studied: no heat input on the left evaporator, the fixed heat input on the left evaporator, and the fixed total heat input. Experiments are also conducted on the PHP operated in the temperature range of-100 similar to -20 degrees C. Results demonstrate that when no heating on the left evaporator, the minimum right heat input to form the circulating flow is 40 W. The maximum allowable heat flux is 88419.41 W/m(2), which is the 200 W heat input. When there is no heating on the left evaporator, as the heat input on the right side increases, the temperature oscillation experiences: small oscillation, severe fluctuation, stable operation, slight fluctuation, stable operation, and intermittent fluctuation. The heating on the left evaporator relieves the stagnation caused by the movement lag of the working fluid and promotes the flow motion. When the total heat input is fixed, the overall thermal resistance of the PHP is little influenced by the exchange of the heat input of the left and right evaporators, instead, it is decided by the amount of the total heat input. The decrement of the working temperature improves the amplitude of the temperature oscillation but also results in the degradation of the thermal performance of the PHP. The optimal working temperature is discovered to be -40 degrees C.

关键词： Ethane pulsating heat pipe Asymmetric heating Temperature oscillation Thermal performance Pulse tube refrigerator

来源：评论

学校读者我要写书评

暂无评论

Techno-economic analysis of an advanced polygeneration liquid air energy storage system coupled with LNG cold energy, solar energy, and hydrate based desalination

引用

ENERGY CONVERSION AND MANAGEMENT 2023年 297卷

作者： Lu, Yilin Chen, Xi Xu, Jingxuan Tian, Yafen Zhang, Hua Univ Shanghai Sci & Technol Sch Energy & Power Engn 516 Jungong Rd Shanghai 200093 Peoples R China Univ Shanghai Sci & Technol Shanghai Key Lab Multiphase Flow & Heat Transfer P 516 Jungong Rd Shanghai 200093 Peoples R China

Energy management and freshwater production are recent social concerns due to the population explosion. However, conventional liquid air energy storage (LAES) systems and desalination approaches face low efficiency and high energy consumption challenges. The present paper proposes a novel LAES system coupled with LNG cold energy, solar energy, and hydrate based desalination (HBD) to bridge the research gap at the intersection of electricity and freshwater production. The system develops the respective integration of external cold and heat sources in energy storage and release processes to strengthen the operational characteristics. Additionally, the proposed LAES employs HBD systems in LNG regasification and energy release processes, thus taking advantage of underutilized cold energy. The non-dominated sorting genetic algorithm II is developed to obtain the optimum operating parameters regarding peak shaving and water production. The optimized system is thoroughly analyzed from the energy, exergy, and economic perspectives. The results indicate that the system with 2805.26 tons of daily freshwater production has an electrical round-trip efficiency of 145.57% and an exergy efficiency of 72.34%. A high positive net present value of 158.17 million USD is achieved. Overall, the efficient system, with superior techno-economic performance, provides an extraordinary alternative to enhance the energy management-water nexus in grid dimensions.

关键词： Liquid air energy storage LNG regasification External energy utilization Hydrate based desalination Multi -objective optimization Techno-economic analysis

来源：评论

学校读者我要写书评

暂无评论

Regulation of rapid boiling of nanofluids on the hybrid wall: A molecular dynamics simulation

引用

INTERNATIONAL JOURNAL OF heat AND MASS transfer 2022年第PartA期183卷 122059-122059页

作者： Wang, Zhao Li, Ling Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China

In this article, the molecular dynamics method is used to study the rapid boiling phenomenon of Cu-H2O nanofluids on the hydrophilic wall, hydrophobic wall, and hydrophilic-hydrophobic hybrid wall (HW), revealing the influence of the hybrid wall on the vaporisation form and boiling heat transfer of the nanofluid. The simulation system is divided into three parts: liquid water molecules, a hydrophilic copper nanoparticle, and copper walls. When the wall temperature is 700 K, the influence of the hydrophilic wall, the hydrophobic wall, and the HW of three different ratios (0.1:0.9, 0.5:0.5, 0.9:0.1) on the vaporisation form and boiling heat transfer of the nanofluid is discussed. The results show that compared with the hydrophilic or hydrophobic wall, the HW changes the vaporisation form of the nanofluid on the wall, and the HW is beneficial to improve the boiling heat transfer performance of the nanofluid. Moreover, the higher the ratio of the hydrophilic side of the HW, the earlier the liquid will boil, the higher the liquid temperature, the greater the potential energy of solid-liquid interaction, which is conducive to improve the boiling heat transfer. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Rapid boiling Evaporation Cu-H2O nanofluid Hybrid wall Molecular dynamics simulation

来源：评论

学校读者我要写书评

暂无评论

Quantitative experimental research on vortex generation and self-maintenance mechanisms in turbulence

引用

PHYSICS OF FLUIDS 2023年第5期35卷 055118-055118页

作者： Dong, Xiangrui Li, Yuyan Cai, Tianyi Zhou, Wu Cai, Xiaoshu Dong, Yinlin Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Key Lab Multiphase Flow & Heat Transfer Shanghai P Shanghai 200093 Peoples R China Univ Cent Arkansas Dept Math Conway AR 72035 USA

Turbulence is not completely random, but contains organized and multi-scale structures. Vortices have always been recognized as the most important coherent structure in turbulent flow, playing a significant role in the generation, evolution, and maintenance of turbulence. In the present work, the vortex formation and evolution process of a fully developed turbulent boundary layer in a rectangular channel flow is experimentally studied by moving-single frame and long exposure and moving-particle image velocimetry measurements. The Rortex integral (RI) method is proposed for quantitative statistics on the critical vortex core size as well as the accurate rotation strength during the evolution process. In this paper, the vortex regeneration and self-maintenance mechanisms in near-wall turbulent flow are experimentally revealed and quantified by the RI method, to give some revelations for the future research on the turbulence theory. On the one hand, three behaviors of the hairpin vortex regeneration are discovered to play a significant role in turbulence development: (A) hairpin regeneration induced by the interaction between hairpins and packets;(B) auto-generation of multiple hairpin vortex in one packet (secondary and tertiary hairpins);and (C) the merging of hairpin vortices in the packets. On the other hand, the circulation process, which contains a mass of young vortex growth with the parent self-decaying, is verified to sustain and promote the development of turbulence. In consequence, the self-sustaining turbulence theory based on mother-child hairpins generation mechanism is supported by the experimental results.

关键词： Turbulence

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：