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NUMERICAL SIMULATION ON VELOCITIES OF TWO INTERACTING FIBERS IN FIBER SUSPENSION

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Journal of Hydrodynamics 2003年第3期15卷 10-16页

作者： Lin Jian-zhong, Bao Fu-bing, Zhang Zhi-chao Department of Mechanics, state key laboratory of Fluid Power Transmission and control, Zhejiang University, Hangzhou 310027, China, Lab. of Fluid Power Transmission Dept. of Mech. Zhejiang Univ. Hangzhou 310027 China

A mathematical model was put forward to describe the mechanical interactionsof two contacting fibers, then a numerical simulation was carried out. The results of the simulationaccord with experimental results well. It turns out that the initial contacting point and theinitial orientation of the settling fiber have much effect on the translational and rotationalvelocities of the settling fiber, along with the increase in the length or the decrease in theradius of the fiber, the translational and rotational velocities of the settling fiber decrease; thesame trend remains when the viscosity of the solvent increases or the density of the fiberdecreases.

关键词： fiber suspension mechanical interaction numerical simulation

Heterogeneous reaction of SO_2 on TiO_2 particles

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Science China Chemistry 2010年第12期53卷 2637-2643页

作者： SHANG Jing,LI Jia & ZHU Tong state key Joint laboratory of Environmental Simulation and Pollution control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China state key Joint laboratory of Environmental Simulation and Pollution control College of Environmental Sciences and Engineering Peking University Beijing China

The heterogeneous reaction of SO2 on TiO2 particles was studied using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).The influences of the oxygen concentration,relative humidity (RH),and ultraviolet (UV) light illumination (λ=365 nm) intensity on the reaction were *** main product of the heterogeneous reaction of SO2 on TiO2 particles was sulfate with UV illumination and sulfite without *** production of sulfate was promoted significantly with UV illumination or water,and there was a synergistic effect when both were *** the dry system without UV,the heterogeneous reaction of SO2 on TiO2 particles was found to be second-order for SO2 and the initial uptake coefficient,BET,was determined to be 1.94 × *** UV and RH=40%,the reaction order was first-order and the initial uptake coefficient was 1.35 × 10-5.

关键词： SO2 TiO2 DRIFTS heterogeneous oxidation

Heterogeneous reactions of gaseous methanesulfonic acid with calcium carbonate and kaolinite particles

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Science China Chemistry 2010年第12期53卷 2657-2662页

作者： TANG MingJin,LI MengQiu & ZHU Tong state key Joint laboratory of Environmental Simulation and Pollution control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China state key Joint laboratory of Environmental Simulation and Pollution control College of Environmental Sciences and Engineering Peking University Beijing China

Heterogeneous reactions of gaseous methanesulfonic acid (MSA) with calcium carbonate (CaCO3) and kaolinite particles at room temperature were investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatography (IC).Methanesulfonate (MS-) was identified as the product in the condensed phase,in accordance with the product of the reaction of gaseous MSA with NaCl and sea salt *** the concentration of gaseous MSA was 1.34 × 10-13 molecules cm-3,the uptake coefficient was (1.21 ± 0.06) × 10-8 (1) for the reaction of gaseous MSA with CaCO3 and (4.10 ± 0.65) × 10 10 (1) for the reaction with *** uptake coefficients were significantly smaller than those of the reactions of gaseous MSA with NaCl and sea salt particles.

关键词： gaseous MSA heterogeneous reaction calcium carbonate kaolinite

BINARY COMPETITIVE AND COOPERATIVE ADSORPTION OF AROMATIC COMPOUNDS ON POLYMERIC RESINS

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Chinese Journal of Polymer Science 2005年第5期23卷 503-511页

作者： Wei-ming Zhang Jin-long Chen Bing-cai Pan Quan-xing Zhang state key laboratory of Pollution control and Resources Reuse,School of the Environment,Nanjing University,Nanjing 210093,China state key laboratory of Pollution control and Resources Reuse School of the Environment Nanjing University Nanjing 210093 China

The adsorption behaviors of 2-naphthalenesulfonic acid and aniline on a conventional macroporous resin Amberlite XAD4 and the other two newly-developed hypercrosslinked resins NDA101 and NDAI00 were investigated in a single or binary batch system at 293 K and 313 K, respectively. All the adsorption isotherms of 2-naphthalenesulfonic acid and aniline on the test resins in both systems can fit well with the Langmuir equation, indicating that the adsorption is a favorable process. At the identical equilibrium concentration, the amount of aniline adsorbed on polymeric resins in the single system is higher than that in the binary system because of the competitive adsorption between 2-naphthalenesulfonic acid and aniline on the resin surface. However, the uptake amount of 2-naphthalenesulfonic acid in the binary system is markedly larger than that in the single system, which is presumably due to the cooperative effect arisen from the electrostatic interaction between 2-naphthalenesulfonic acid and aniline adsorbed on the resin surface. The simultaneous adsorption system was proven to be helpful for the selective adsorption toward 2-naphthalenesulfonic acid due to its larger selective index.

关键词： Polymeric resin 2-Naphthalenesulfonic acid Aniline Competitive adsorption Cooperative adsorption.

A HIGH-ORDER-ACCURATE DIFFERENCE SCHEME WITH UNCONDITIONAL STABILITY FOR THE DIFFUSION EQUATION ON NONUNIFORM GRIDS

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Journal of Hydrodynamics 2001年第1期13卷 92-98页

作者： Wang Xuan, Yang Zhi-feng state key laboratory of Environment Simulation and Pollution control, Institute of Environmental Sciences, Beijing Normal University, Beijing 100875, China[WT5”HZ] Beijing Normal Univ. Beijing 100875 China

WT5”BZ]A high-order-accurate difference scheme with unconditional stability is developed for the diffusion equation on nonuniform grids. The theoretical analysis shows that the accuracy of this scheme is between third order and fourth order, and fourth-order accuracy is achieved in the case of the same grid steps being used within the computational domain. Two numerical examples are given to demonst ate the advantages of the proposed scheme. Compared with the conventional difference scheme, more accurate numerical solution can be obtained by using the proposed scheme even with relatively larger grid sizes. It is also pointed out that the appropriate structure of the nonuniform grid can not only make the proposed scheme more practical, but lead to a solution superior to that for a uniform grid structure. [WT5”HZ]

关键词： ]finite difference scheme diffusion equation nonuniform grid high accuracy computational fluid dynamics

The Construction of Numerical Scheme forHyperbolic Equation and Exact Considerationof Numerical Diffusion and Dispersion

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 156-162页

作者： Qingdong CAI(state key laboratory for Turbulence Research, Peking University, Beijing 100871, China) state key laboratory for Turbulence Research Peking University Beijing 100871 China

A new technique in the formulation of numerical scheme for hyperbolicequation is developed. It is different from the classical FD and FE methods. We begin withthe algebraic equations with some undefined parameters, and get the difference equationthrough Taylor-series expansion. When the parameters in the partial difference equationare defined, the equation is what the scheme will simulate. The numerical example ofthe viscous Burgers equation shows the validity of the scheme. This method deals withthe numerical viscosity and dispersion exactly, giving a preliminary explanation to someproblems that the CFD face now.

关键词： modified equation Taylor expansion consistency truncation error

Transport and deposition of nanoparticles in bend tube with circular cross-section

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Progress in Natural Science:Materials International 2009年第1期19卷 33-39页

作者： Peifeng Lin a,Jianzhong Lin a,b,a state key laboratory of Fluid Power Transmission and control,Zhejiang University,Hangzhou 310027,China b China Jiliang University,Hangzhou 310018,China state key laboratory of Fluid Power Transmission and control Zhejiang University Hangzhou 310027 China China Jiliang University Hangzhou 310018 China

Transport and deposition of nanoparticles in bend tube with circular cross-section were simulated numerically for different Reynolds numbers and Dean numbers.A finite-volume code and the SIMPLE scheme were used to solve the *** results show that the distribution of nanoparticle concentration is symmetrical with respect to the top and bottom sides of the *** diameter of the nanoparticles has a weak effect on the distribution of nanoparticle *** maximum and minimum of the deposition enhancement factor occur near the outside and inside walls of the bend tube,*** higher the Reynolds number is,the shorter is the time for nanoparticle *** bend curvature radius has a slight effect on the deposition enhancement factor.

关键词： Nanoparticles Transport Deposition Numerical simulation

A　NEW　METHOD　FOR　SOLVING　TURBULENT　VELOCITY　CORRELATION　FUNCTIONS　AND　ITS　APPLICATION　TO　THE　CHANNEL　FLOW

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Journal of Hydrodynamics 1996年第4期8卷 69-77页

作者： Lin Jian-zhong Wang Yu-zhi(Department of Mechanics, the state key laboratory of Fluid Power Transmission and control, Zhejiang University Hangzhou 310027, P. R. China) Zhejiang Univ Hangzhou China

A new kind of method, the method of successive substitution, for solving velocity correlation functions is presented. As application of this method, the first order approximation solution in the turbulent channel flow is given numerically and then put into the equations of turbulent fluctuation which are solved numerically within the range of micro-scale by means of spectrum method and finite-difference method. By averaging fluctuating velocity, the second order approximation solutions of double fluctuating velocity correlation and other higher order correlations are obtained by computation. Putting the second approximation solution into equations of turbulent fluctuation, the solutions of different order correlations are given. These results are in good agreement with experimental results [1, 2, 3].

关键词： turbulence correlation functions computation method

CORRECTION METHODS FOR STEADY INCOMPRESSIBLE FLOWS

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Journal of Computational Mathematics 1999年第4期17卷 419-424页

作者： Jian Li(state key laboratory of Scientific and Engineering Computing, ICMSEC, Chinese Academy of Sciences, Beijing 100080, China) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京

Correction methods for the steady semi-periodic motion of incompressible fluid are investigated. The idea is similar to the influence matrix to solve the lack of vorticity boundary conditions. For any given boundary condition of the vorticity, the coupled vorticity-stream function formulation is solved. Then solve the governing equations with the correction boundary conditions to improve the solution. These equations are numerically solved by Fourier series truncation and finite difference method. The two numerical techniques are employed to treat the non-linear terms. The first method for small Reynolds number R equals 0-50 has the same results as that in M. Anwar and S.C.R. Dennis' report. The second one for R greater than 50 obtains the reliable results. (Author abstract) 4 Refs.

关键词： incompressible flow vorticity stream function numerical solution