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EFFECT OF SWEEP AND EJECTION EVENTS ON PARTICLE DISPERSION IN WALL BOUNDED TURBULENT FLOWS

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Journal of Hydrodynamics 2012年第5期24卷 794-799页

作者： LUO Jian-ping LU Zhi-ming QIU Xiang LI Dong-mei LIU Yu-lu School of Mechanical Engineering Shanghai Institute of Technology Shanghai 200235 China shanghai Key Laboratory of Mechanics in Energy Engineering and shanghai institute of Applied Mathematicsand Mechanics Shanghai University Shanghai 200072 China School of Science Shanghai Institute of Technology Shanghai 200235 China shanghai institute of technology Shanghai 200235 China

This paper studies the sweep and ejection events in a channel flow with Reτ = 80 by using Direct Numerical Simulation （DNS）. The effects of ejection and sweep events on the transport of fluid particles are analyzed separately through a quadrant technique. By analyzing trajectories of the particles released at different wall-normal locations, it is found that the particles from the ejection events mainly move upward while the particles from the sweep events move downward of the flow during short and intermediate diffusion time durations. Numerical results show that the effects of the ejection and sweep events on the mean displacement and the mean square dispersion remain for a long time, one-order of magnitude larger than the streamwise Lagrangian integral ~cales.

关键词： sweep ejection dispersion quadrant analysis turbulent channel flow

High-temperature oxidation behavior and degradation mechanism of chromium-coated zirconium alloy cladding: a review

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Tungsten 2025年第1期 50-70页

作者： Yi Li Bei-Qi Wang Xin-Yin Zhang Shi-Jie Wang Cong-Yi Li Hui-Long Yang Ran-Ran Su Tong Liu School of Mechanical Engineering Shanghai Jiao Tong University College and Graduate School of Arts and Sciences University of Virginia Global institute of Future technology Shanghai Jiao Tong University

Accident-tolerant fuels(ATF) have been extensively studied to reduce the production rate and total amount of heat and hydrogen generated from high-temperature steam oxidation during severe ***-coated zirconium alloy cladding has become one of the most promising candidates for ATF because of its excellent corrosion and oxidation *** paper provides a comprehensive overview of the research progress on oxidation behaviors and degradation mechanisms in chromium-coated zirconium alloy cladding under high-temperature *** techniques to strengthen the oxidation resistance are highlighted and ***,challenges and opportunities for various future directions are addressed.

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Dry Reforming of Ethane over FeNi/Al-Ce-O Catalysts:Composition-Induced Strong Metal-Support Interactions

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Engineering 2022年第11期18卷 173-185页

作者： Tao Zhang Zhi-Cheng Liu Ying-Chun Ye Yu Wang He-Qin Yang Huan-Xin Gao Wei-Min Yang State Key Laboratory of Green Chemical Engineering and industrial Catalysis Sinopec Shanghai Research Institute of Petrochemical TechnologyShanghai 201208China

Dry reforming of ethane(DRE)has received significant attention because of its potential to produce chemical raw materials and reduce carbon ***,a composition-induced strong metal-support interaction(SMSI)effect over FeNi/Al-Ce-O catalysts is revealed via X-ray photoelectron spectroscopy(XPS),H_(2)-temperature programmed reduction(TPR),and energy dispersive X-ray spectroscopy(EDS)elemental *** introduction of Al into Al-Ce-O supports significantly influences the dispersion of surface active components and improves the catalytic performance for DRE over supported FeNi catalysts due to enhancement of the SMSI *** catalytic properties,for example,C_(2)H_(6) and CO_(2) conversion,CO selectivity and yield,and turnover frequencies(TOFs),of supported FeNi catalysts first increase and then decrease with increasing Al content,following the same trend as the theoretical effective surface area(TESA)of the corresponding *** FeNi/Ce-Al_(0.5) catalyst,with 50%Al content,exhibits the best DRE performance under steady-state conditions at 873 *** observed by with in situ Fourier transform infrared spectroscopy(FTIR)analysis,the introduction of Al not only increases the content of surface Ce3+and oxygen vacancies but also promotes the dispersion of surface active components,which further alters the catalytic properties for DRE over supported FeNi catalysts.

关键词： Dry reforming of ethane Strong metal-support interaction Carbon dioxide Ceria Oxygen vacancy Reaction mechanism

Analysis of temperature time series based on Hilbert-Huang Transform

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Journal of Hydrodynamics 2015年第4期27卷 587-592页

作者：马皓邱翔罗剑平顾品强刘宇陆 School of Mechanical Engineering Shanghai Institute of Technology School of Science Shanghai Institute of Technology shanghai Meteorological Service in Fengxian District shanghai institute of Applied Mathematics and Mechanics Shanghai University

In this paper, with consideration of the nonlinear and non-stationary properties of the temperature time series, we employ the Hilbert-Huang Transform, based on the empirical mode decomposition（EMD）, to analyze the temperature time series from 1959 to 2012 in the Fengxian district of shanghai, obtained from a certain monitoring station. The oscillating mode is drawn from the data, and its characteristics of the time series are investigated. The results show that the intrinsic modes of 1, 2 and 6 represent the periodic properties of 1 year, 2.5 years, and 27 years. The mean temperature shows periodic variations, but the main trend of this fluctuation is the rising of the temperature in the recent 50 years. The analysis of the reconstructed modes with the wave pattern shows that the variations are quite large from 1963 to 1964, from 1977 to 1982 and from 2003 to 2006, which indicates that the temperature rises and falls dramatically in these periods. The volatility from 1993 to 1994 is far more dramatic than in other periods. And the volatility is the most remarkable in recent 50 years. The log-linear plots of the mean time scales T and M show that each mode associated with a time scale almost twice as large as the time scale of the preceding mode. The Hilbert spectrum shows that the energy is concentrated in the range of low frequency from 0.05 to 0.1 Hz, and a very small amount of energy is distributed in the range of higher frequency over 0.1 Hz. In conclusion, the HHT is better than other traditional signal analysis methods in processing the nonlinear signals to obtain the periodic variation and volatility＇s properties of different time scales.

关键词： atmospheric turbulence temperature time series empirical mode decomposition(EMD) Hilbert Huang Transform

Vortex shedding in the flow around two side-by-side circular cylinders of different diameters

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Journal of Hydrodynamics 2017年第3期29卷 470-478页

作者：邱翔毕贞晓罗剑平刘宇陆 School of Science Shanghai Institute of TechnologyShanghai 201418China School of Mechanical Engineering Shanghai Institute of TechnologyShanghai 201418China shanghai institute of Applied Mathematics and Mechanics Shanghai UniversityShanghai 200072China

In this paper,the 3-D turbulent flow around two side-by-side circular cylinders of different diameters,at sub-critical Reynolds number（Re=3 900）,is numerically simulated by the large eddy simulation（LES）.The spacing ratios（T/D）between the two cylinders are considered in four cases（T/D=1.2,1.5,1.8 and 2.7）to study the vortex shedding and turbulent properties in the flow *** main results are focused on the drag and lift coefficients,the vortex shedding frequency,the coherent structure,and the scale *** is shown that when T/D is equal to 1.2,the vortex shedding of the main cylinder is strongly suppressed by the small cylinder,the drag and lift coefficients of the main cylinder are smaller than those in other three *** T/D is equal to 1.5,the vortex shedding of the main cylinder can be improved,the drag and lift coefficients of the main cylinder are larger than those in other three *** empirical mode decomposition（EMD）method is applied to decompose the velocity signals traced by the *** is shown that there is a linear relationship between the mean period and the mode in the semi-log *** vortex shedding period of the main cylinder is consistent with the period of the restructured coherent structures quantitatively.

关键词： Large eddy simulation(LES) drag and lift coefficients vortex shedding frequency empirical mode decomposition(EMD)

Tuning interaction strength between CeO_(2) and iridium to promote CO oxidation over Ir/TiO_(2)

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Journal of Rare Earths 2024年第4期42卷 651-659页

作者： Lu Dai Binghua Li Yuhan Peng Xianwei Hao Runquan Xuan Hua Huang Yiming Bi Liping Xu Yanhui Zhang Yun Guo Fangqi Du Li Wang Hui Wang technology Center China Tobacco Zhejiang Industrial Co.Ltd.Hangzhou310024China Research institute of industrial Catalysis East China University of Science and TechnologyShanghai200237China

The interaction between support and noble metal plays a crucial role in heterogeneous catalysis ***,how to tune metal support interactions to optimize the activity still needs further ***_(2) was introduced to promote CO oxidation ove r Ir/TiO_(2) by adjusting the interaction strength between iridium(Ir)and CeO_(2).The strong interaction between Ir and CeO_(2) blocks CO adsorption and causes low CO oxidation ***,introducing CeO_(2) on Ir/TiO_(2) produces localized interaction between Ir and CeO_(2),which can tune the surface electronic state of Ir,so a"volcano curve"relationship between CO oxidation activity and electronic state is *** amount of CeO_(2) on Ir/TiO_(2)(Ir/Ce_(0.2)Ti)leads to CO complete oxidization at 22℃,and a new pathway for CO oxidation was *** study demonstrates that the utilization of tuning interaction strength between active metal and support is a potential method to increase the catalytic activity.

关键词： CO oxidation CeO_(2) Localized interaction Interaction strength Supported Ir catalysts Rareearths

Synthesis of Fischer indole derivatives using carboxyl-functionalized ionic liquid as an efficient and recyclable catalyst

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Chinese Chemical Letters 2009年第3期20卷 275-278页

作者： Feng Ping Yi Hai Yang Sun Xian Hua Pan Yuan Xu Ji Zong Li School of Perfume and Aroma technology Shanghai Institute of Technology Shanghai 200235 China College of Food Science & technology Shanghai Ocean University Shanghai 201306 China shanghai Technological and industrial Promotion Center of Traditional Chinese Medicine Shanghai 201203 China

Fischer indole cyclization of phenylhydrazine and various ketones using carboxyl-functionalized ionic liquid, 1-carboxymethyl- 3-methylimidazolium tetrafluoroborate （abbreviated as [crnmim] [BF4]） as catalyst was successfully performed. The yields of the target compounds were 80-92%, the purities were 96-98%. The catalyst could be recovered and reused for at least six times without significant loss in activity.

关键词： Functionalized ionic liquid Catalyst Fischer indole synthesis

Removal of perfluorinated surfactants from wastewater by adsorption and ion exchange--Influence of material properties,sorption mechanism and modeling

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Journal of Environmental Sciences 2017年第4期29卷 160-170页

作者： Falk Schuricht Ekaterina S.Borovinskaya Wladimir Reschetilowski institute of industrial Chemistry Dresden University of Technology

Perfluorooctane sulfonate（PFOS） has attracted increasing concern in recent years due to its world-wide distribution, persistence, bioaccumulation and potential toxicity. The influence of sorbent properties on the adsorptive elimination of PFOS from wastewater by activated carbons, polymer adsorbents and anion exchange resins was investigated with regard to their isotherms and kinetics. The batch and column tests were combined with physicochemical characterization methods, e.g., N2 physisorption, mercury porosimetry, infrared spectroscopy, differential scanning calorimetry, titrations, as well as modeling. Sorption kinetics was successfully modelled applying the linear driving force（LDF） approach for surface diffusion after introducing a load dependency of the mass transfer coefficient β*** big difference in the initial mass transfer coefficient βs,0, when non-functionalized adsorbents and ion-exchange resins are compared, suggests that the presence of functional groups impedes the intraparticle mass transport. The more functional groups a resin possesses and the longer the alkyl moieties are the bigger is the decrease in sorption *** the selectivity for PFOS sorption is increasing when the character of the functional groups becomes more hydrophobic. Accordingly, ion exchange and hydrophobic interaction were found to be involved in the sorption processes on resins, while PFOS is only physisorptively bound to activated carbons and polymer adsorbents. In agreement with the different adsorption mechanisms, resins possess higher total sorption capacities than adsorbents. Hence, the latter ones are rendered more effective in PFOS elimination at concentrations in the low μg/L range, due to a less pronounced convex curvature of the sorption isotherm in this concentration range.

关键词： PFOS Activated carbon Anion exchange resin Sorption kinetics modeling Sorption isotherm Selectivity of sorption

Asymptotic solutions of the flow of a Johnson-Segalman fluid through a slowly varying pipe using double perturbation strategy

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Applied Mathematics and Mechanics(English Edition) 2018年第2期39卷 169-180页

作者： Xinyin ZOU Xiang QIU Jianping LUO Jiahua LI P.N.KALONI Yulu LIU School of Mechanical Engineering Shanghai Institute of Technology School of Science Shanghai Institute of Technology College of Urban Construction and Safety Engineering Shanghai Institute of Technology Department of Mathematics and Statistics University of Windsor shanghai institute of Applied Mathematics and Mechanics Shanghai University

A double perturbation strategy is presented to solve the asymptotic solutions of a Johnson-Segalman （J-S） fluid through a slowly varying pipe. First, a small parameter of the slowly varying angle is taken as the small perturbation parameter, and then the second-order asymptotic solution of the flow of a Newtonian fluid through a slowly varying pipe is obtained in the first perturbation strategy. Second, the viscoelastic parameter is selected as the small perturbation parameter in the second perturbation strategy to solve the asymptotic solution of the flow of a J-S fluid through a slowly varying pipe. Finally, the parameter effects, including the axial distance, the slowly varying angle, and the Reynolds number, on the velocity distributions are analyzed. The results show that the increases in both the axial distance and the slowly varying angle make the axial velocity slow down. However, the radial velocity increases with the slowly varying angle, and decreases with the axial distance. There are two special positions in the distribution curves of the axial velocity and the radial velocity with different Reynolds numbers, and there are different trends on both sides of the special positions. The double perturbation strategy is applicable to such problems with the flow of a non-Newtonian fluid through a slowly varying pipe.

关键词： Johnson-Segalman (J-S) fluid slowly varying pipe double perturbationstrategy velocity distribution