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Neural network-based interface reconstruction algorithm for two-phase fluid flow

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Fundamental Research 2025年

作者： Gong, Junhua Chen, Yujie Yu, Bo Sun, Dongliang Wang, Bohong Shi, Guoyun Chen, Bin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China School of Mechanical Engineering Beijing Institute of Petrochemical Technology Beijing 102617 China School of Petroleum Engineering Yangtze University Wuhan 430100 China National & Local Joint Engineering Research Center of Harbor Oil & Gas Storage and Transportation Technology/Zhejiang Key Laboratory of Pollution Control for Port-Petrochemical Industry Zhejiang Ocean University Zhoushan 316022 China Kunlun Digital Intelligence Technology Company Beijing 102266 China

In two-phase fluid flow, the vapor-liquid interface tends to behave as a curved shape under the influence of surface tension. Curve reconstruction favors improving the resolution of bubbles or droplets in numerical studies. Based on artificial neural network (ANN) and convolutional neural network (CNN), two curve reconstruction algorithms, namely CIR-ANN and CIR-CNN, are proposed in this study. Both algorithms can achieve high-precision prediction of the center and radius when reconstructing interfaces using a portion of a standard circle, especially for the CIR-CNN algorithm. A strict mass conservation strategy is also proposed to ensure the reliability of the neural network predictions. In comparison with interface reconstruction algorithms such as piecewise linear interface construction (PLIC) algorithm, efficient least squares volume-of-fluid interface reconstruction algorithm (ELVIRA), quadratic spline based interface (QUASI) reconstruction algorithm after the first interface correction, Circle-based Interface Reconstruction (CIR), and CIR-ANN algorithm, the proposed CIR-CNN demonstrates good advantages in static interface reconstruction, with average accuracy ratios of 48.40, 86.69, 26.34, 4.07 and 2.26. However, when capturing the bubble under a complex rotation and shear recovery flow field, the advantage of the proposed algorithms decreases due to the increased complexity of the fluid volume fraction distributions. Regarding the computational time cost of reconstructing random circular interfaces, the proposed algorithms achieve average reduction ratios of 4.16, 7.86, and 34.14, respectively, compared to the CIR, ELVIRA, and QUASI algorithms. © 2025

关键词： ANN CNN Curve reconstruction Neural network Two-phase flow

Enhanced Hydrogen Production of Acidified Ruddlesden-Popper Type Perovskite Oxides in Water and Seawater by Coupled Piezo-Photocatalysis

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SSRN 2022年

作者： Ma, Xinyu Gao, Yangfei Yang, Bian Lou, Xiaojie Huang, Jianbing Ma, Lijing Jing, Dengwei International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi'An710049 China Frontier Institute of Science and Technology State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University Xi'An710049 China School of Materials Science and Engineering Xi’an University of Technology Xi’an Xi'An710048 China

Photocatalytic water splitting for hydrogen production is more sustainable than traditional desalination and electrocatalysis, because of avoiding electrode corrosion and other problems. Two-dimensional perovskite oxide materials have multiple characteristics such as ferroelectric, piezoelectric and pyroelectric properties, demonstrating good light response and chemical stability, which provides a broad prospect in photo-chemical conversion. In this study, acidified La2NiO4 can greatly improve the amount of hydrogen evolution by coupling its piezocatalysis and photocatalysis. Under the full-spectrum illumination assisted with ultrasonic vibration in seawater, a recordable hydrogen production activity of 1315.44 μmol·g-1·h-1 was obtained in acidified La2NiO4 by 0.006 mol/L HCl, which more than 200 times higher than that of pure La2NiO4 (6.89 μmol·g-1·h-1) in methanol solution. It is found that the significant hydrogen production of La2NiO4 samples treated with acidification lies in the fast separation of charge carriers in comparison with those without acidification. In addition, the hydrogen production efficiency of seawater is higher than that of pure water, because the inorganic salt acts as a sacrificial agent and changes the surface charge of the catalyst. This work contributes to the in-depth understanding of piezo-photocatalysis and thus provides a new solution for improving the performance of multi-field coupling hydrogen production. © 2022, The Authors. All rights reserved.

关键词： Hydrogen production

Modeling and prediction of ultrasonic attenuations in liquid-solid dispersions containing mixed particles with Monte Carlo method

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Particuology 2019年第2期17卷 84-91页

作者： Jianfei Gu Fengxian Fan Yunsi Li Huinan Yang Mingxu Su Xiaoshu Cai Institute of Particle and Two-Phase Flow Measurement/Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China

We develop a theoretical model for predicting the ultrasonic attenuation in the liquid-solid system containing mixed particles. The ultrasonic attenuation coefficient is obtained by counting the number of phonons that reach the receiver. Using the Monte Carlo method (MCM), numerical simulations were performed to predict the ultrasonic attenuations with not only a single particle type but also monodisperse and polydisperse mixed particles. The simulation results for the systems with a single particle type were compared with various standard models. The results show that they agree well at relatively low particle volume concentrations (within 10%). For systems with mixed particles, the particle volume concentrati on was found to in crease to around 10%, and the variation of the ultrasonic attenuation agai nst the mixing ratio yields a nonlinear trend. Moreover, the ultrasonic attenuation is significantly affected by particle properties. The numerical results also show that both the particle type and particle size distribution should be carefully taken into account in the dispersions with polydisperse mixed particles, where the MCM can give a more direct description of the physics of sound propagation compared with the conventional models.

关键词： Ultrasound Ultrasonic attenuation Monte Carlo method Particle size measurement

Sacos-Plate: A New Thermal-Hydraulic Subchannel Analysis Code for Plate Type Fuel Assemblies

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SSRN 2023年

作者： Sun, Ruiyu Wang, Jianjun Wang, Jinshun Chen, Ronghua Jiang, Xing Tian, Wenxi Qiu, Suizheng Su, Guanghui Gui, Minyang Harbin Engineering University China School of Nuclear Science and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University China State Key Lab. of Multiphase Flow in Power Engineering Xi’an Jiaotong University China Shanghai Nuclear Engineering Research Design Institute Shanghai China

Over the past few decades, plate-type fuel elements have been widely used in advanced research reactors, small modular pressurized water reactors, production reactors, etc., with the advantages of compact structure arrangement, good heat transfer characteristics and high fuel consumption. Currently, a thermal-hydraulic subchannel analysis code, namely SACOS-PLATE code, was newly designed to satisfy the calculation of different types of plate fuel elements under various steady-state operating conditions. Based on the original SACOS code, this updated version modifies the flow distribution model, the plate heat conduction model, the heat distribution model as well as the flow heat transfer model, and then realizes the simulation of the special thermal-hydraulic phenomena of the fuel and the rectangular flow channel. In this present study, the RA-6 experimental data was used to validate the code, and the simulation calculation was performed on the JRR-3 research reactor, which proved the good computing capability of SACOS-PLATE code. © 2023, The Authors. All rights reserved.

关键词： Plates (structural components)

Insight into the Interconversions of Three-Phase Products Through the Supercritical Water Gasification of Bark

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SSRN 2023年

作者： Ge, Hui Yi, Lei Huang, Yong Peng, Pai Cao, Wen Chen, Yunan Qi, Xingang Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University No.28 Xianning West Road Xi'An710049 China International Institute for Innovation Jiangxi University of Science and Technology Jiangxi 341000 China Suzhou Academy Xi’an Jiaotong University No.99 Ren’ai Road Jiangsu Suzhou215123 China

The clean and efficient utilization of biomass waste for hydrogen production conforms to social development in the future. In this work, hydrogen production from supercritical water gasification (SCWG) of fir bark (FB) was investigated systematically at various reaction temperatures (500–750 °C), feedstock concentrations (5%–15%), and retention time (0–40 min). The gaseous, liquid, and solid products were analyzed comprehensively to determine the gasification mechanism. The results demonstrated that FB was the alternative feedstock for hydrogen production. The maximum CE and H2 selectivity of 95.34% and 0.99 were obtained at 700 °C-5%-40 min. High reaction temperature and prolonging retention time accelerated the conversions of phenolic compounds in liquid products and functional groups in solid products. High feedstock concentration also resulted in the bond-making between functional groups in solid products. The reaction mechanism was proposed based on the components of gaseous and liquid products and the variations of functional groups in solid products. © 2023, The Authors. All rights reserved.

关键词： Hydrogen production

Core-shell Ag-Pt nanoparticles:A versatile platform for the synthesis of heterogeneous nanostructures towards catalyzing electrochemical reactions

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Chinese Chemical Letters 2021年第11期32卷 3288-3297页

作者： Danye Liu Niuwa Yang Qing Zeng Hui Liu Dong Chen Penglei Cui Lin Xu Chaoquan Hu Jun Yang State Key Laboratory of Multiphase Complex Systems and Center of Mesoscience Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Nanjing IPE Institute of Green Manufacturing Industiy Nanjing 211100China School of Chemistry and Materials Science Jiangsu Key Laboratoiy of New Power BatteriesNanjing Normal UniversityNanjing 210023China

Heterogeneous nanostructures that are defined as a hybrid structure consisting of two or more nanoscale domains with distinct chemical compositions or physical characteristics have attracted intense efforts in recent *** this review,we focus on the introduction of a number of heterogeneous nanostructures derived using core-shell Ag-Pt nanoparticles as starting materials,including hollow,dimeric and composite structures and also highlight their application in catalyzing electrochemical reactions,e.g.,methanol oxidation reaction and oxygen reduction *** review not only shows the capability of core-shell Ag-Pt nanoparticles in producing various heterogeneous nanostructures as starting templates,but also highlights the structural design or electronic interaction that endows the heterogeneous nanostructures with enhanced catalytic properties either in methanol oxidation or in oxygen ***,we also make some perspectives for more heterogeneous nanostructures that may be prepared by using core-shell Ag-Pt particles or their derivatives so as to offer the readers the opportunities and challenges in this field.

关键词： Heterogeneous nanostructures Core-shell Electrochemical reaction Methanol oxidation reaction Oxygen reduction reaction

Energy consumption characteristics and energy saving potential of thermal power plants under ultra-low power load ratio conditions

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Energy 2025年 330卷

作者： Du, Zeyu Liu, Ming Wang, Yang Zhou, Yu Zhao, Yongliang Yan, Junjie Xi'an Jiaotong University State Key Laboratory of Multiphase Flow in Power Engineering Xi'an710049 China China Huaneng Group Co LTD Beijing100032 China

The operational flexibility of thermal power plants should be enhanced to accommodate the high penetration of photovoltaic and wind power within the power grid. The energy efficiency deteriorates heavily when thermal power plants operate under ultra-low power load ratio conditions, which will increase the carbon emissions of the low-carbon power system. To achieve the energy saving under ultra-low power load ratio condition, the CFPP's (coal-fired power plant) off-design condition models were developed, and the thermal system regulation with additional losses of the CFPP operates under below 30 % power load ratio condition was simulated. Then, influences of the degradation factors on the energy consumption characteristics under ultra-low power load ratio condition were evaluated. Moreover, the carbon emission rate of power generation considering the renewable power accommodation was evaluated. Results show the degradations of turbines' internal efficiencies are the main source of internal losses, and the degradation of boiler's efficiency and the increase of the auxiliary power ratio are the main source of external losses. The total carbon emission rate of power generation decreases by 21.98 g/(kW h) with the power load ratio of CFPP decreasing from 30 % to 20 % due to the increased accommodation of renewable power. Finally, energy saving potential evaluations under ultra-low power load ratio conditions were conducted. The net coal consumption rate is 298.56 g/(kW h) and 522.39 g/(kW h) when the thermal power plant operates under 100 % and 20 % power load ratio conditions respectively. The maximal energy saving potential of bnet under ultra-low power load condition are 87.25, 29.47, 25.05, 2.33 and 1.05 g/(kW h), for the degradation of isentropic efficiency of turbine, the degradation of boiler's efficiency, the increase of auxiliary power ratio, the additional drainage water of the boiler and the switching action of BFPT's supply steam, respectively. © 2025 Elsevie

关键词： Fossil fuel power plants

Numerical study of collision behavior of melt drops during fuelcoolant interaction

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Numerical study of collision behavior of melt drops during f...

2020 International Conference on Nuclear engineering, ICONE 2020, collocated with the ASME 2020 power Conference

作者： Wen, Panpan Li, Gen Gao, Jinchen Li, Yupeng Yamaji, Akifumi Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Cooperative Major in Nuclear Energy Waseda University Tokyo169-8555 Japan

ISBN: (纸本)9780791883785

The collision dynamics between two droplets plays an important role in various disciplines of nature and practical interests, such as fuel-coolant interaction (FCI), fuel combustion in engines, and various spraying process. FCI presents in nuclear reactor severe accident when the melt relocates into the coolant in the lower head with violent disturbance and vigorous heat transfer. The purpose of this study is to investigate the collision behavior of melt droplets during fuel-coolant interaction. The collision of two equal-sized droplets has been simulated in 3D by using the volume of fluid (VOF) and adaptive mesh refinement method. The numerical simulations of tetradecane droplet collision were carried out to validate the numerical methods. The results showed good agreement with the experiments. Furthermore, the simulations of uranium dioxide (UO2) droplets collision in coolant were carried out. The results showed that the contact area between droplets and coolant increased with time first and then decreased. With the increase of Weber number, the contact area of maximum in the droplet collision increased. Break happened in the later period and many child droplets formed. The number of child droplets increased with the increase of Weber number. In addition, the size distribution of little droplets was investigated. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Coolants

Suppressing Condensation Frosting Using Micropatterned Ice Walls

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SSRN 2022年

作者： Zuo, Zichao Zhao, Yugang Li, Kang Zhang, Hua Yang, Chun 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 Key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development Center Sichuan Mianyang621000 China School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore639798 Singapore

Condensation frosting is encountered ubiquitously in our daily life and numerous industrial applications, rooting many detrimental consequences in heat transfer and mechanical stabilities. In latest decades, both active de-frosting and passive anti-frosting methods have been developed. In this work, we adopt the concept of three-dimensional overlapping dry zones by patterning microscopic ice walls on a smooth substrate, engendering a sustainable frost coverage of less than 10%. Patterned ice walls prevent vapor deposition on the substrate base by absorbing all incoming moisture on upper sidewalls, leaving the substrate base free of contaminates from both frost and condensate. To ensure vapor preferentially depositing on upper sidewalls, a critical ice wall height exists, below which fine ice grains initiate in the adjacent of the substrate base and grow substantially faster, compromising the anti-frosting performance. The proposed surface shows reasonable durability when exposed to varying substrate supercooling, and frost coverage may increase due to covering and fracturing of the out-of-plane growth of feather-like ice clusters at large substrate supercooling. Our findings provide an effective anti-frosting surface design that doesn’t require any chemical or mechanical modifications on the targeted surfaces, showing great advantages compared to conventional icephobic surface designs. © 2022, The Authors. All rights reserved.

关键词： Ice