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Simulation of high velocity compaction of powder in a two dimension mould using lattice Boltzmann method

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Acta Metallurgica Sinica(English Letters) 2012年第1期25卷 47-54页

作者： Qiaojie LI zhoushun zheng Xuanhui QU School of Mathematical Science and Computing Technology Central South University Changsha 410083China School of Materials Science and Engineering University of Science and Technology Beijing Beijing100083 China

This work presents a numerical study on the dynamic high velocity compaction of the metal powder. The analysis of the process is based on a mesoscopic approach using multi-speed lattice Boltzmann method. The boundary condition and the relaxation time are tailored to the situation. The dynamic compaction process is vividly presented and the shock wave can be easily found in the simulation. The density is analyzed in order to explore the mechanism of the high velocity compaction.

关键词： High velocity compaction Lattice Boltzmann method Shockwave Relaxation time function

Numerical Simulation of Powder Injection Molding Filling Process Based on ANSYS

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Journal of Materials Science & Technology 2003年第Z1期19卷 144-146页

作者： zhoushun zheng Xuanhui QU Yunping LI Jianfeng GUO National Key Lab for Powder Metallurgy Central South University Changsha 410083 China Department of Applied Mathematics and Applied Software Central South University Changsha 410083 China National Key Lab for Powder Metallurgy Central South University Changsha 410083 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China National Key Lab for Powder Metallurgy Central South University Changsha 410083 China National Key Lab for Powder Metallurgy Central South University Changsha 410083 China

A mathematical model of two-dimensional flows of PIM derived from the momentum, continuity equations and theheat transfer equation is obtained. The formula of calculating the flow conductance and the pressure equation arededuced when the no slip boundary condition is employed at the wall, and the pressure equation is a non-linearelliptic partial differential equation. The flow front locations, distribution of velocities, temperature and pressure aresimulated by the finite element analysis software ANSYS. Simulation results indicate that it is in the final filled partthat defects appear easily. The region in which the defects may occur during the PIM process can be predicted.

关键词： Numerical simulation, Powder injection molding, Mathematical model, ANSYS

CALTPP:A general program to calculate thermophysical properties

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Journal of Materials Science & Technology 2020年第7期42卷 229-240页

作者： Yuling Liu Cong Zhang Changfa Du Yong Du zhoushun zheng Shuhong Liu Lei Huang Shiyi Wen Youliang Jin Huaqing Zhang Fan Zhang George Kaptay State Key Lab of Powder Metallurgy Central South UniversityChangshaHunan 410083China Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Mathematics and Statistics Central South UniversityChangshaHunan 410083China School of Materials Science and Engineering Xiangtan UniversityXiangtanHunan 411105China Department of Nanotechnology University of MiskolcH-3515 MiskolcEgyetemvarosHungary

A program CALTPP(CALculation of ThermoPhysical Properties)is developed in order to provide various thermophysical properties such as diffusion coefficient,interfacial energy,thermal conductivity,viscosity and molar volume mainly as function of temperature and *** thermophysical properties are very important inputs for microstructure simulations and mechanical property *** general structure of CALTPP is briefly described,and the CALPHAD-type models for the description of these thermophysical properties are *** CALTPP program contains the input module,calculation and/or optimization modules and output module.A few case studies including(a)the calculation of diffusion coefficient and optimization of atomic mobility,(b)the calculation of solid/liquid,coherent solid/solid and liquid/liquid interfacial energies,(c)the calculation of thermal conductivity,(d)the calculation of viscosity,and(e)the establishment of molar volume database in binary and ternary alloys are demonstrated to show the features of *** is expected that CALTPP will be an effective contribution in both scientific research and education.

关键词： Thermophysical property Diffusion coefficient Interfacial energy Thermal conductivity Viscosity Molar volume CALPHAD-type modeling

Finite Element Method for a Kind of Two-Dimensional Space-Fractional Diffusion Equation with Its Implementation

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American Journal of Computational Mathematics 2015年第2期5卷 135-157页

作者： Beiping Duan zhoushun zheng Wen Cao School of Mathematics and Statistics Central South University Changsha China

In this article, we consider a two-dimensional symmetric space-fractional diffusion equation in which the space fractional derivatives are defined in Riesz potential sense. The well-posed feature is guaranteed by energy inequality. To solve the diffusion equation, a fully discrete form is established by employing Crank-Nicolson technique in time and Galerkin finite element method in space. The stability and convergence are proved and the stiffness matrix is given analytically. Three numerical examples are given to confirm our theoretical analysis in which we find that even with the same initial condition, the classical and fractional diffusion equations perform differently but tend to be uniform diffusion at last.

关键词： Galerkin Finite Element Method Symmetric Space-Fractional Diffusion Equation Stability Convergence Implementation

Numerical Solution of Nonlinear Klein-Gordon Equation Using Lattice Boltzmann Method

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Applied Mathematics 2011年第12期2卷 1479-1485页

作者： Qiaojie Li Zong Ji zhoushun zheng Hongjuan Liu 不详

In this paper, in order to extend the lattice Boltzmann method to deal with more nonlinear equations, a one-dimensional (1D) lattice Boltzmann scheme with an amending function for the nonlinear Klein-Gordon equation is proposed. With the Taylor and Chapman-Enskog expansion, the nonlinear Klein-Gordon equation is recovered correctly from the lattice Boltzmann equation. The method is applied on some test examples, and the numerical results have been compared with the analytical solutions or the numerical solutions reported in previous studies. The L2, L∞ and Root-Mean-Square (RMS) errors in the solutions show the efficiency of the method computationally.

关键词： Lattice Boltzmann Chapman-Enskog Expansion Nonlinear Klein-Gordon Equation

The Intelligent Control Method of the Density of the Metal Injection Molding Billet based on ANN

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The Intelligent Control Method of the Density of the Metal I...

中国材料大会2012

作者： zhoushun zheng Ruirui Leng The Mathematics and statistics institute of the Central South Uiversity

ISBN: (纸本)9783037856093;3037856092

According to the metal powder injection molding process,the main influence factors of injection molding billet density distribution（such as:injection velocity,injection temperature,injection pressure,etc） was analyzed and a multiple input ＆ multiple output BP neural network model for injection molding was build up to predict the density distribution of the billet intelligently based on ANN and *** addition,in light of the requirements for the density distribution of the metal injection molding billet,the influence factors were controlled *** this model in the metal injecting process,the density distribution of billet was predicted according to the injection parameters and the injection parameters was optimized according to the required density distribution of the *** the result,the error was less than 5% between the prediction values and the actual values of the density distribution of *** the optimized injection parameters to the injection process,the density distribution of billet closed to the requirements was achieved.

关键词： ANN GA Intellectualization.

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PIM充模流动过程中粘度的变化与缺陷形成

金属学报 2007年第2期43卷 187-193页

作者：郑洲顺曲选辉雷长明中南大学数学科学与计算技术学院长沙410083 北京科技大学材料科学与工程学院北京100083 中南大学粉末冶金国家重点实验室长沙410083

通过对复杂几何形腔粉末注射成形(PIM)充模流动过程的数值模拟,给出了充模流动过程中模腔内粘度的变化和分布情况,分析了模腔内粘度的最终分布与PIM缺陷形成的关系．模拟结果表明,由于模腔接近充满时压力急剧升高构成无梯度压力场,导致... 详细信息

通过对复杂几何形腔粉末注射成形(PIM)充模流动过程的数值模拟,给出了充模流动过程中模腔内粘度的变化和分布情况,分析了模腔内粘度的最终分布与PIM缺陷形成的关系．模拟结果表明,由于模腔接近充满时压力急剧升高构成无梯度压力场,导致模腔内粘度的最终分布复杂．在充模流动中心区域会形成较高粘度的小区域,分析了这些高粘度小区域的形成及其形状大小的变化过程．指出在流动中心区域形成的高粘度小区域可能使PIM充模流动过程产生粉末-粘结剂两相分离和成形坯件中粉末分布不均的现象．

关键词：粉末注射成形数值模拟粘度分布缺陷分析

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基于离散单元法的粉末高速压制流动过程模拟

稀有金属材料与工程 2010年第12期39卷 2132-2136页

作者：郑洲顺王爽郑珊曲选辉中南大学湖南长沙410083 北京科技大学北京100083

将离散单元法应用于粉末高速压制流动过程研究,以模拟粉体流动的非连续特性。将粉末视为粘弹性的离散颗粒,推导了力与位移表达的粉末高速压制粘弹性本构关系,建立了粉末高速压制成形颗粒流动的离散单元法控制方程;并给出了该模型的动态... 详细信息

将离散单元法应用于粉末高速压制流动过程研究,以模拟粉体流动的非连续特性。将粉末视为粘弹性的离散颗粒,推导了力与位移表达的粉末高速压制粘弹性本构关系,建立了粉末高速压制成形颗粒流动的离散单元法控制方程;并给出了该模型的动态松弛法求解过程。基于离散单元法求解器PFC软件,对粉末高速压制成形过程颗粒流动情况及密度分布进行了模拟,模拟结果与实验结果较吻合。分析了阻尼系数变化对求解过程的敛散性和压坯密度分布的影响。

关键词：离散单元法粉末高速压制成形流动情况过程模拟 Discrete Element Method Based Velocity High 求解过程密度分布粘弹性本构关系离散颗粒动态松弛法阻尼系数实验结果模拟结果连续特性控制方程过程研究

Numerical simulation of multiphase flow for PIM filling process and study on the powder-binder separation

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Numerical simulation of multiphase flow for PIM filling proc...