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International Journal of Hydrogen Energy 2010年第13期35卷 7027-7027页

作者： Liejin Guo State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University China

Core/Shell Structured Hematite Nanorod Arrays as Photoanodes for Efficient Solar Water Oxidation

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Core/Shell Structured Hematite Nanorod Arrays as Photoanodes...

IUPAC 9th International Conference on Novel Materials and their Synthesis(NMS-IX) & 23rd International Symposium on Fine Chemistry and Functional Polymers(FCFP-XXIII)(IUPAC第九届新型材料和合成国际会议暨第23届国际精细化工和功能聚合物研讨会)

作者： S.Shen Samuel S.Mao Department of Mechanical Engineering University of California at BerkeleyBerkeley CA 94720 United States Department of Mechanical Engineering University of California at BerkeleyBerkeley CA 94720 United States International Research Center for Renewable State Key Laboratory of Multiphase Flow in Power Engineering Xi''an Jiaotong University Shaanxi 710049 China

Insight into the key Role of Imine Groups in Polyaniline for Adsorbing Heavy Metal Ions: Density Functional Theory and Experimental Study

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SSRN 2023年

作者： Shi, Bofang Li, Hang Fu, Xiaojie Zhao, Chengcheng Wang, Angelina H. Tan, Weilin Rao, Yongfang Li, Mingtao Komarneni, Sridhar Yang, Honghui Xi’an Key Laboratory of Sustainable Energy Materials Chemistry Department of Applied Chemistry School of Chemistry Xi’an Jiaotong University Xi’an710049 China State Key Laboratory of Multiphase Flow in Power Engineering Department of Environmental Science and Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Department of Ecosystem Science and Management Materials Research Institute 204EEL The Pennsylvania State University University ParkPA16802 United States

In polyaniline (PANI) or PANI-based adsorbents, views on which nitrogen group has the highest chemical affinity to heavy metal ions and dominates the adsorption process remain in debate. Herein, we focus on deciphering the main adsorption sites and adsorption mechanisms of PANI using both density functional theory (DFT) calculations and experiments. The theoretical DFT calculations reveal that −N= group, rather than other groups within PANI, is the adsorption site. And the key step of PANI adsorption process is a ligand exchange reaction. In addition, H+ ions with a higher affinity to −N= group can inhibit the adsorption of metal ions through the consumption of adsorption sites and ion exchange reaction. X-ray photoelectron spectra (XPS) spectra demonstrate that maintaining a reasonably high pH value (pH > 4) is an effective way to weaken H+ competition. This work provides a molecular-level understanding of adsorption sites, adsorption mechanism, and H+ competition for metal ion adsorption by PANI, which is beneficial for the development of PANI-based adsorbents. © 2023, The Authors. All rights reserved.

关键词： Adsorption

Ethylene Oxidation with Ce-Modified Fe-Based Oxygen Carrier: Fuel Combustion Efficiency Improvement

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SSRN 2022年

作者： Sun, Tianli Wu, Ye Mei, Jian Han, Yinghui Cai, Tianyi Liu, Dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing210094 China Advanced Combustion Laboratory School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing210094 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China

Improving combustion efficiency of diesel engine is very important in the current background of carbon neutralization because sufficient combustion means low pollutant emission and little energy waste. In past studies, catalytic coatings were used in diesel engine to speed up fuel-burning rates and reduce emissions caused by insufficient combustion. Insufficient combustion mainly in high temperature and low oxygen area, using oxygen carrier as the coating material for the combustor surface to support additional –O and regulate the combustion process also is a promising strategy. A desired Fe-based oxygen carrier with excellent redox capability and stability was fabricated to convert fuel pyrolysis products into CO2, H2O and extra heat to improve the fuel combustion efficiency. A range of cerium modified Fe2O3 oxygen carriers were prepared and tested with ethylene as a representative fuel to investigate the redox capability and stability during fuel pyrolysis process. In addition, the gas-solid surface reaction of ethylene and iron oxide was studied by density functional theory (DFT) to illustrate their good reactivity and the mechanism of doping optimization. It was found that when using the FeCe-2 oxygen carrier with the mole ration of Fe and Ce is 9:1 during ethylene pyrolysis process, the ethylene was oxidized most sufficiently (CO2 yield>92%). DFT simulation showed that Ce doping improved the reactivity of surface oxygen. Experimental data and characterization analysis showed that the addition of Ce improved oxygen vacancy capacity to enhance the oxidation for the pyrolysis products. Due to the role of both, the ethylene and its pyrolysis products were converted into CO2 and H2O quickly and effectively. The obtained results indicate that FeCe-2 is the potential oxygen carrier coating material for combustion efficiency improvement. © 2022, The Authors. All rights reserved.

关键词： Carbon dioxide

Experimental Study of Pool Boiling Heat Transfer on Hydrophilic and Hydrophobic Surface Coupled Micro-Pin-Finned

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SSRN 2023年

作者： Song, Gege Ma, Xiang Xu, Pengzhuo Zhang, Yonghai Weia, Jinjia School of Chemical Engineering and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China Xi’an Navigation Technology Research Institute Shannxi Xi’an710068 China Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

The pool boiling heat transfer properties of uniform micro-pin-finned surface, hydrophilic and hydrophobic surface were evaluated by employing FC-72 as the working medium. Three hydrophilic and hydrophobic coupled rectangular copper column surfaces (HH4, HH9, and HH16) were invented in order to investigate their boiling heat transfer characteristics further. The effect of several subcoolings (0K, 15K, and 25K) on the critical heat flux was explored by connecting the micro-pin-finned surface (PF) and the smooth surface (SS). A high-speed camera was set up to study the bubbles' behaviors. The results reveal that the hydrophilic and hydrophobic coupled micro-pin-finned copper surface can achieve a higher critical heat flux (CHF) than the rectangular micro-pin-finned surface, but heat transfer performance (HTC) drops slightly (both saturated boiling and subcooling boiling). Visual monitoring demonstrates that the hydrophilic and hydrophobic coupled rectangular micro-pin-finned copper surface may successfully avoid bubble coalescence, especially during subcooled boiling. Furthermore, the hydrophilic and hydrophobic coupled rectangular micro-pin-finned copper column surface described in this paper might serve as an ideal replenishment route to avoid drying and delay the emergence of a boiling crisis. The factors responsible for the impact of the Lattice width coefficient and the Vapor column spacing coefficient on CHF were analyzed. Fluid replenishment and bubble formation behavior were applied to clarify the strengthened heat transfer and triggering mechanism of CHF on the surface of the hydrophilic and hydrophobic coupled rectangular micro-pin-finned copper column surface. © 2023, The Authors. All rights reserved.

关键词： Heat flux

Adaptive Growing Randomized Neural Networks for Solving Partial Differential Equations

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arXiv

arXiv 2024年

作者： Dang, Haoning Wang, Fei Jiang, Song School of Mathematics and Statistics Xi’an Jiaotong University Shaanxi Xi’an710049 China School of Mathematics and Statistics State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China Institute of Applied Physics and Computational Mathematics Beijing100088 China

Randomized neural network (RNN) methods have been proposed for solving various partial differential equations (PDEs), demonstrating high accuracy and efficiency. However, initializing the fixed parameters remains a challenging issue. Additionally, RNNs often struggle to solve PDEs with sharp or discontinuous solutions. In this paper, we propose a novel approach called Adaptive Growing Randomized Neural Network (AG-RNN) to address these challenges. First, we establish a parameter initialization strategy based on frequency information to construct the initial RNN. After obtaining a numerical solution from this initial network, we use the residual as an error indicator. Based on the error indicator, we introduce growth strategies that expand the neural network, making it wider and deeper to improve the accuracy of the numerical solution. A key feature of AG-RNN is its adaptive strategy for determining the weights and biases of newly added neurons, enabling the network to expand in both width and depth without requiring additional training. Instead, all weights and biases are generated constructively, significantly enhancing the network’s approximation capabilities compared to conventional randomized neural network methods. In addition, a domain splitting strategy is introduced to handle the case of discontinuous solutions. Extensive numerical experiments are conducted to demonstrate the efficiency and accuracy of this innovative approach. Copyright © 2024, The Authors. All rights reserved.

关键词： Partial differential equations

A New Reduced Reaction Mechanism of the Surrogate Fuel for RP-3 Kerosene

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SSRN 2022年

作者： Liu, Jing Hu, Erjiang Zheng, Weilin Zeng, Wen Chang, Yachao State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shangxi Xi’an710049 China Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University Liaoning Shenyang110136 China Key Laboratory of Ocean Energy Utilization and Energy Conservation Ministry of Education Dalian University of Technology Dalian116024 China

By combining the reaction class-based global sensitivity analysis (RC-GSA) methodology, species sensitivity analysis (SSA) methodology, decoupling method and genetic algorithm (GA), a reduced reaction mechanism of the surrogate fuel (10% n-dodecane/14% n-decane/30% iso-hexadecane/36% methylcyclohexane/10% toluene, in mole fraction) for RP-3 kerosene was constructed. As an example, the detailed construction process of skeleton mechanism of methylcyclohexane (MCH) was presented, and the skeleton mechanism constructions of other components in the surrogate fuel were similar to that of MCH. First, the dominant reaction classes in the fuel-relevant mechanism of MCH were recognized by the RC-GSA, the representative species in each retained reaction classes were selected by the SSA, and the skeleton fuel-relevant mechanism of MCH was developed. Second, through combining the skeleton fuel-relevant mechanism of MCH with the reduced reaction mechanism of C 0 -C 3 by the decoupling method, the initial skeleton mechanism of MCH was obtained. Third, based on the GA, the rate constants of fuel-relevant reactions in the initial skeleton mechanism of MCH were optimized to enhance the prediction performance. Finally, by coupling the skeleton reaction mechanisms of n-dodecane, n-decane, toluene, iso-hexadecane, MCH, and the reduced reaction mechanism of C 0 -C 3 , a reduced mechanism (containing 121 species and 469 reactions) of the surrogate fuel for RP-3 kerosene was formed. The predicted main species concentrations during the oxidation process in the jet-stirred reactor, the ignition delay times in the shock tube and laminar flame speeds in the constant volume bomb by this reduced mechanism are in good agreement with the corresponding experimental data of RP-3 kerosene. © 2022, The Authors. All rights reserved.

关键词： Sensitivity analysis

Numerical simulation on forced convection heat transfer in porous media using Gibson‐Ashby constitutive model

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AIP Conference Proceedings 2010年第1期1207卷

作者： J. X. Wang P. Y. Jia Y. S. Wang L. Jiang State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University China

In this article, using Gibson‐Ashby constitutive model, we suggest a new method for numerical investigation of forced convection heat transfer in porous foam metal, and try to consolidate the study for mechanical property and that for thermal characteristic. By available experimental data, we simulated to two cases, namely as the transfer in porous media for diameter is 0.6 mm and porosity is 0.402, and for diameter is 1.6 mm and porosity is 0.462. The result, from our constitutive model for single forced convection heat transfer, corresponds well with the experimental data. As for pressure drop prediction in porous is in good agreement with experiment, and the error is only 5% to 10%, but for transfer is less accurate, the error is about 20%, which is acceptable in practice. So it is done that constitutive model is used to simulate the transfer property.

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Publisher's Note: Numerical investigation of the yawed wake and its effects on the downstream wind turbine [J. Renewable Sustainable Energy 8, 033303 (2016)]

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Journal of Renewable and Sustainable Energy 2016年第5期8卷

作者： Miao, Weipao Li, Chun Yang, Jun Xie, Xiaoyun School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China Laboratory of Fluid and Power Machinery Xihua University Jinniu District Sichuan610000 China Shanghai Behr Thermal Systems Co. Pudong District Shanghai201206 China

This article was originally published online on 9 June 2016 with affiliation 3 incorrectly assigned to the second author. Chun Li is not affiliated with the Lab

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The Role of Particle-Vortex Interaction in Hydraulic Performance and Erosion Behavior of Semi-Open Centrifugal Pump: Effect of Particle Size

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SSRN 2023年

作者： Wang, Kai Liu, Hanyu Wang, Like Guo, Pengcheng Wang, Yueshe Yang, Junfeng State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi’an University of Technology No.5 Jinhua South Road Xi’an710048 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University No.28 Xianning West Road Xi’an710049 China Shaanxi Provincial Dongzhuang Water Conservancy Engineering Co. Ltd Xi’an713200 China

The interaction between the particle migration and vortex evolution aggravates the complexity of erosion on the flow components. In this work, the liquid-solid two-phase flow of semi-open centrifugal pump under different particle sizes is simulated based on the four-way coupling Euler-Lagrange method, in which the fluid-particle interaction and particle-particle interaction are taken into account. The interrelationship among vortex structure, particle migration and surface erosion behavior is revealed. The results show that the erosion area is mainly distributed in the blade leading edge, the pressure surface inlet edge and the hub. When the particle size is 0.1 mm and 0.3 mm, due to the good following characteristic of particles and the inhibition effect on tip leakage vortex, the particles are easy to impact the outlet edge of blade suction surface and the hub, which induce severe erosion. As the particle size decreases, the number of particles flowing into the tip clearance layer increases. Therefore, the frequent impact of particles on the tip leakage vortex leads to the breakup, separation and refusion of the vortex, which aggravates the flow instability. This paper provides a new insight into the hydraulic performance and erosion characteristics of semi-open centrifugal pump in terms of particle-vortex interaction. © 2023, The Authors. All rights reserved.

关键词： Particle size