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Nanoparticle-induced drag reduction for polyacrylamide in turbulent flow with high Reynolds numbers

Chinese Journal of Chemical engineering 2023年第4期56卷 290-298页

作者： Xiaoping Li Jiaxin Pan Jinwen Shi Yanlin Chai Songwei Hu Qiaorong Han Yanming Zhang Xianwen Li Dengwei Jing State Key Laboratory of Multiphase Flow in Power Engineering&International Research Center for Renewable Energy Xi'an Jiaotong UniversityXi'an 710049China Oil and Gas Technology Research Institute of Petrochina Changqing Oilfield Company Xi'an 710018China

Although having been increasingly studied, there is still controversy as to when the addition of nanoparticles could improve the drag reduction performance of polymer drag reducer and particularly what is the underlying mechanism from the fluid dynamics viewpoint. The drag reduction effects of adding SiO_(2) nanoparticles to various polymer polyacrylamide(PAM) solutions were examined in this *** optimal combination of SiO_(2) nanoparticles with cationic polyacrylamide was ***,the addition of SiO_(2) nanoparticles to cationic polyacrylamide solution was shown to be quite efficient for reducing drag, but only at higher flow rates with Reynolds numbers more than 6000, below which the nanoparticle addition is even negative. The addition of SiO_(2) nanoparticles to the PAM solution is supposed to play a dual role. The first is an increase in flow resistance caused by the Brownian motion of nanoparticles, while the second is a decrease in flow resistance caused by acting as nodes to protect the polymer chain from shear-induced breaking under high shear action. At optimal nanoparticle concentration and under higher Reynolds numbers, the later effect is dominant, which could improve the drag reduction performance of polymer drag reducers. Our work should serve as a guide for the application of natural gas fracturing, where the flow rate is frequently very high.

关键词： Drag reduction SiO_(2)nanoparticle Cationic polymer Brownian motion

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Comparison of hydrogen generation rate between cora-13 test and MELCOR simulation: Clad solid-phase oxidation models using self-developed code MYCOAC

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Nuclear Technology 2015年第1期192卷 25-34页

作者： Wang, Jun Corradini, Michael L. Haskin, Troy Zhang, Yapei Lu, Qing Tian, Wenxi Su, Guanghui Qiu, Suizheng Xi'an Jiaotong University State Key Laboratory of Multiphase Flow in Power Engineering Xi'an710049 China University of Wisconsin-Madison College of Engineering MadisonWI53706 United States Nuclear Power Institute of China Chengdu610041 China

To better understand the MELCOR oxidation and degradation models, past work compared the MELCOR model to a CORA experiment (CORA Test 13). These MELCOR analyses specifically focused on fuel bundle heatup and clad oxidation when compared to CORA test data. The comparison allowed the authors to investigate differences between hydrogen generation data and simulation results. Several potential reasons were considered for hydrogen generation rate differences, including MELCOR input power, heat transfer modeling, the clad solid-phase oxidation model, and the gaseous steam diffusion model. This work focuses on the possible uncertainty in the clad oxidation models used in MELCOR. First, the MELCOR nodalization approach for the CORA test was reviewed. Then, the temperature history and spatial variation were examined. One main focus was to consider other clad solid-phase oxidation models to compare the MELCOR models. This was accomplished by developing a separate model, MYCOAC, using MELCOR temperature predictions as input. Finally, the mass transfer resistance of steam diffusion to the clad surface was examined and found to be a small effect. While the Baker-Just solid-phase oxidation model showed better agreement with CORA data at low temperatures, the conclusion in this paper is that the oxidation models are not the major source of uncertainty in hydrogen generation rate differences. Future work will focus on heat transfer modeling of the CORA test.

关键词： Diffusion

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Numerical simulation of ignition of coke-oven gas on an industry boiler

Numerical simulation of ignition of coke-oven gas on an indu...

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International Conference on Frontiers of Energy, Materials and Information engineering, ICFMEI 2014

作者： Shi, Hong Wei Wang, Shuai Wang, Dong Zhang, Xing Kai State key lab of multiphase flow in power engineering Xi'an jiaotong university Xi’an China

ISBN: (纸本)9783038352778

Some coking plants discharge coke-oven gas to the environment,this pollute the *** order to solute the problem,the paper proposed a method:using coke-oven gas instead of light oil to ignite the *** virtue of doing this was to save *** FLUENT software package to simulate ignition in boiler is a effective mean,it can show the distribution of temperature in the *** simulation result shows that using CFD methods can provide ideas for the operation of the boiler. © (2014) Trans Tech Publications, Switzerland.

关键词： Computational fluid dynamics

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Polarized imaging dynamic light scattering for simultaneous measurement of nanoparticle size and morphology

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Particuology 2024年第2期85卷 213-223页

作者： Bingyao Wang Tianyi Cai Xiaoshu Cai Wu Zhou Zeqi Liu Schoolof Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093China Jiaxing MeaParTech Instrument Technology Co. LtdZhejiang314000China

The performance of nanoparticles is often affected by particle size and ***,electron microscopy or atomic force microscopy is typically utilized to determine the size and morphology of ***,there are issues such as difficult sample preparation,long processing times,and challenges in quantitative ***,it is of great significance to develop a fast,accu-rate,and statistical method to measure the size and morphology of *** this study,a new method,called polarized imaging dynamic light scattering(PIDLS),is *** nanoparticles are irradiated with a vertical linearly polarized laser beam,and a polarization camera collected the dynamic light scattering images of particles at four different polarization directions(0°,45°,90°,and 135°)at a scattering angle of 90°.The average particle size and distribution are obtained using the imaging dy-namic light scattering method at 0°polarization direction,and the morphology of the particles is ob-tained based on the depolarization patterns of the scattered *** optical sphericityΦis defined based on the degree of linear polarization(DoLP).It is also implemented for the quantitative evaluation of the sphericity of the nanoparticles,including spherical,octahedral,nanoplate,nanorod,and linear *** with the Poincarésphere parameterψ,the morphology of the nanoparticles can be roughly *** addition,PIDLS enables the measurement of particle size and morphology distributions simultaneously for evaluating the uniformity of *** effectiveness of PIDLS is verified by the measurement of five kinds of industrial titanium dioxide as well.

关键词： Imaging dynamic light scattering Polarized light scattering Non-spherical nanoparticles Morphology Online measurement

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EXPERIMENTAL STUDY ON GAS-LIQUID TWO-PHASE flowS IN AN AREATION TANK BY USING IMAGE TREATMENT METHOD

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Journal of Hydrodynamics 2008年第5期20卷 650-655页

作者： CHENG Wen LIU Wen-hong HU Bao-wei WAN Tian State Key Laboratory of Multiphase Flow in Power Engineering Xi＇an Jiaotong University Xi＇an 710049 China Environment Research Institute Xi＇an University of Technology Xi＇an 710048 China Environment Research Institute Xi＇an University of Technology Xi＇an 710048 China

Particle Image Velocimetry （PIV） technique was employed to study experimentally gas-liquid two-phase flow in an aeration tank. In terms of the PIV principles, an algorithm of PIV based on the Fast Fourier Transformation （FFT） was worked out. The PIV program was developed and verified, and then was used to measure three kinds of states in the testing device. The program was also used to calculate and analyze the related parameters. The experimental data indicate that the bubbles in testing device have the longest resident time and stronger turbulent intensity for the gas-liquid two-phase flow in a special case （Case 3）, resulting in great increase of the oxygen transferring speed and efficiency, whereby providing the basis for the selection design of aeration tank.

关键词： gas-liquid two-phase flow Particle Image Velocimetry (PIV) Fast Fourier Transformation (FFT) aeration tank

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Study on TMD Control on Stability Improvement of Barge-Supported Floating Offshore Wind Turbine Based on the Multi-Island Genetic Algorithm

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China Ocean engineering 2019年第3期33卷 309-321页

作者： DING Qin-wei LI Chun CHENG Shan-shan HAO Wen-xing HUANG Zhi-qian YU Wan School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093 China School of Engineering University of Plymouth Devon PL4 8AA UK

A floating offshore wind turbine (FOWT) has a great potential in producing renewable energy as offshore wind resource is rich in deep sea area (water deeper than 60 m) where fixed foundations are cost-effective or deployable. However, compared with a fixed-bottom installation, FOWT has to suffer more extreme loads due to its extra degrees of freedom. Therefore, the stability of an FOWT is a key challenge in exploiting offshore deep-water wind. Focusing on the stability of barge-type FOWT, this paper is to investigate the effect of passive structural control by equipping a tuned mass damper (TMD) on the nacelle. The turbulent wind with sharp fluctuations is established both in velocity and inflow direction based on standard Kaimal turbulence spectrum as suggested in the standard IEC61400-2. The irregular wave is generated according to the Pierson-Moskowitz spectrum. The dynamic structural characteristics of FOWT are calculated based on the fully coupled aero-hydro-servo-elastic solver FAST. Evidence has shown that the proposed method of the nacelle-based TMD is effective in controlling stability of an FOWT, as the sway and roll motions of barge and the side-side displacement of tower top decreased significantly. With the increase of mass, the side-side displacement of tower-top and the amplitude of roll motion of barge reveal a trend of increasing first and then decreasing. The stiffness and damping have little effect. Furthermore, the multi-island genetic optimization algorithm (MIGA) is employed to find globally optimum structural parameters (mass, stiffness and damping) of the TMD. The optimum structure parameters of TMD are achieved when the mass is 21393 kg, damping is 13635 N/(m/s) and stiffness is 6828 N/m. By adopting the optimized TMD, stability of roll motion of barge and side-side displacement of tower-top increase up to 53% and 50% respectively when compared with the normal TMD. The simulation results verify the validity and reliability of the proposed TM

关键词： FOWT barge TMD MIGA wind wave stability

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A research on ignition of a boiler by using coke-oven gas instead of light oil and alternation of the boiler

A research on ignition of a boiler by using coke-oven gas in...

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International Conference on Frontiers of Energy, Materials and Information engineering, ICFMEI 2014

作者： Shi, Hong Wei Zhang, Xing Kai Wang, Dong Wang, Shuai State key lab of multiphase flow in power engineering Xi’an jiaotong university Xi’an China

ISBN: (纸本)9783038352778

In order to solute the question of boiler ignition in thermal electrical factory of an Aluminun plant, Coke-oven gas was used to substitute for ligtht oil. At the same output of boiler, the cost of start up can be reduced;at low boiler output coke-oven gas can be used to ignite coal, and the ignition was steady. Once upon a time, the coke-oven gas was ignited directly in the air, it wasted energy and caused envirnmental pollution. The coke-oven gas guns were placed in the under secondary air and the middle secondary air, the output of single gas gun was 800Nm3/h;the virtue of the arrangement was to prevent coke-oven gas consuming so much air for the coal. © (2014) Trans Tech Publications, Switzerland.

关键词： Coke

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Study of Heat Transfer in Ice-storage Tank

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Journal of Thermal Science 2001年第4期10卷 357-362页

作者： Anding HeHuanqun QianZhihua HuFangde Zhou state key Lab of multiphase flow in power engineering, Xi’an Jiaotong University, Xi’an, 710049, China State Key Lab of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

The heat transfer process of ice formation on the outside of coil pipe in the ice storage tank with glycol solution as the second refrigerant was studied in this paper analytically and experimentally. A model was developed for the charging process and the conduction shape factor was applied. Also, the result obtained from the model was compared with the experimental data, both data were in agreement. The simple model is useful for the operation, design and optimization of the ice storage tank.

关键词： coil type ice storage charging rate shape factor.

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Development of a filtered drag model considering effect of the solid shear rate

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Particuology 2022年第12期71卷 63-74页

作者： Lingxue Wang Ming Jiang Qiang Zhou School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'an710049China Engineering Research Center of New Energy System Engineering and Equipment University of Shaanxi ProvinceXi'an710049China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an710049China

This study investigates a 2D gas-solid fast fluidized bed of typical Geldart A particles using highly resolved simulations with two-fluid *** results show that the solid shear rate has a considerable impact on the orientation of the meso-scale structures and hence on the filtered drag *** the basis of the correlation for the filtered drag force established in the literature using the traditional markers(such as filtered solid volume fraction,filtered slip velocity and filter scale),a correction correlated with the solid shear rate in the direction of gravity is proposed for better prediction of the filtered drag *** corrected model is shown to produce improved results in posterior tests of flows in different fluidization regimes including bubbling,turbulent and fast fluidization.

关键词： Gas-solid flows Fluidization Two-fluid model Dimensionless solid shear rate Filtered drag force

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Continuous hydrogen production by biomass gasification in supercritical water heated by molten salt flow: System development and reactor assessment

Continuous hydrogen production by biomass gasification in su...

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作者： Xiao, Peng Guo, Liejin Zhang, Ximin Zhu, Chao Ma, Shaohua State Key Laboratory of Multiphase Flow in Power Engineering Xi'An Jiaotong University Xi'an 710049 Shaan Xi Province China

Hydrogen production by biomass gasification using solar energy is a promising approach for overcoming the drawbacks of fossil fuel utilization, but the storage of discontinuous solar flux is a critical issue for continuous solar hydrogen production. A continuous hydrogen production system by biomass gasification in supercritical water using molten-salts-stored solar energy was proposed and constructed. A novel double tube helical heat exchanger was designed to be molten salts reactor for hydrogen production. Model compounds (glycerol/glucose) and real biomass (corn cob) were successfully gasified in this molten salts reactor for producing hydrogen-rich gas. The unique temperature profiles of biomass slurry in the reactor were observed and compared with that of conventional electrical heating and direct solar heating approaches. Product gases yield, gasification efficiency and exergy conversion efficiency of the reactor were analyzed. The results showed that the performances of reactor were determined by feedstock style, biomass concentration, residence time and biomass slurry temperature profiles. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Biomass

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