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A New Algorithm for non-newtonian flow and Its Application in Mould Filling Process

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Journal of Shanghai Jiaotong university(Science) 2011年第1期16卷 1-10页

作者：韩先洪孔啸周雄辉李锡夔 National Die and Mould CAD Engineering Research Center Shanghai Jiaotong University State Key Laboratory of Structural Analysis of Industrial Equipment Dalian University of Technology

The simulation of injection molding process requires a stable algorithm to model the molten polymer with non-isothermal non-newtonian property.In this paper,a staggered and iterative scheme is particularly designed to solve the velocity-pressure-temperature variables.In consideration of the polymer characteristic of high viscosity and low thermal conductivity,the non-newtonian momentum-mass conservation equations are solved by the Crank-Nicolson method based split (CNBS) scheme,and the energy conservation equation with convective character is discretized by the characteristic Galerkin (CG) method.In addition,an arbitrary Lagrangian Eulerian (ALE) free surface tracking and mesh generation method is introduced to catch the front of the fluid flow.The efficiency of the proposed scheme is demonstrated by numerical experiments including a lid-driven cavity flow problem and an injection molding problem.

关键词： non-newtonian flow injection molding finite element method fractional step algorithm

Large Time Behavior of a Weak Solution for non-newtonian flow

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Northeastern Mathematical Journal 2006年第3期22卷 306-322页

作者：吴珞刘辉昭王宗尧 Department of Mathematics East China University of Science and Technology Department of Mathematics Hebei University of Technology

This paper concerns large time behavior of a regular weak solution for non-newtonian flow equations. It is shown that the decay of the solution is of exponential type when the force term is equal to zero and the domain is bounded. Moreover, the ratio of the enstrophy over the energy has a limit as time tends to infinity, which is an eigenvaiue of the Stokes operator.

关键词： large time behavior non-newtonian flow weak solution

Reverse Roll Coating flow with non-newtonian Fluids

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Communications in Computational Physics 2009年第8期6卷 536-552页

作者： Jiin-Yuh Jang Peng-Yuan Chen Department of Mechanical Engineering National Cheng-Kung UniversityTainan70101 Taiwan

In this study an incompressible flow with non-newtonian fluids in the reverse roll coating process was investigated.non-newtonian behavior of the coating fluid was accounted by using power law model with power index,n,ranging from 0.8 to 1.2.Effect of roll speed ratio(V2/V1)of the panel roll to the applicator roll and gap distance on the coating film thickness were also investigated.Numerical results were in good agreement with those of experimental data within 15%-20%.Results indicated that the film thickness ratios are function of power-law index,roll speed ration and ratio of roll radius to gap distance.The equations for film thickness ratio were obtained from numerical results as shown below:■,where t1,t2 and t3 are inlet film,transferred film and leakage film thickness,respectively,n is power-law index,V1 and V2 are roll speed of applicator roll and panel roll,Rm is average radius of two rolls and H0 is gap distance.The correlations are accurate within 10%for 0.8≤n≤1.2,0.5≤V_(2)/V_(1)≤2,and 7.7×10^(−5)≤H_(0)/R_(m)≤1.54×10^(−4).

关键词： Reverse roll coating non-newtonian flow power-law

non-newtonian steady shear flow characteristics of waxy crude oil

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Non-Newtonian steady shear flow characteristics of waxy crud...

Simulating Two-Phase Viscoelastic flows Using Moving Finite Element Methods

The 9th National Conference on Rheology

作者：黄树新陈鑫鲁传敬侯磊范毓润 Department of Engineering Mechanics Shanghai Jiaotong University Department of Petroleum Storage and Transportation China University of Petroleum State Key Laboratory of Fluid Power Transmission and Control Zhejiang University

The experimental research on the non-newtonian flow characteristic of a waxy crude oil was conducted through a rotational parallel-plates rbeometer system.The test temperature is about 6.5℃ higher than its gel point.The shear stress and viscosity of the waxy crude oil show sophisticate non-newtonian characteristics in the shear rate of 10-10 s,in which the shear stress can be divided into three parts qualitatively,i.***.stress-up region,leveling-off region,and stress-up region.This indicates that there is a yielding process in shearing for the waxy crude oil at the experimental temperature,which is similar to the yield phenomenon in thixotropy-loop test discussed by CHANG and BOGER.Furthermore,the steady shear experiment alter the pre- shear process shows that the stress leveling-off region at low shear rate disappears for the waxy crude oil and the stress curve becomes a monotonic climbing one,which demonstrates that the internal structure property presenting through yielding stress at low shear rate can be changed by shearing.The experimental results also show that the internal structure of waxy crude oil presenting at low shear rate has no influence on the shear viscosity obtained at the shear rate higher than 0.1s.The generalized newtonian model is adopted to describe the shear-thinning viscosity property of the waxy crude oil at high shear rate.

关键词： waxy crude oil shear flow non-newtonian flow generalized newtonian model

来源： cnki会议评论

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Communications in Computational Physics 2010年第2期7卷 333-349页

作者： Yubo Zhang Heyu Wang Tao Tang Department of Mathematics Hong Kong Baptist UniversityKowloon TongHong Kong Department of Mathematics Zhejiang UniversityHangzhouZhejiang 310027China

Phase-field models provide a way to model fluid interfaces as having finitethickness;the interface between two immiscible fluids is treated as a thin mixing layeracross which physical properties vary steeply but continuously. One of the main chal-lenges of this approach is in resolving the sharp gradients at the interface. In this paper,moving finite-element methods are used to simulate interfacial dynamics of two-phaseviscoelastic flows. The finite-element scheme can easily accommodates complex flowgeometry and the moving mesh strategy can cluster more grid points near the thin in-terfacial areas where the solutions have large gradients. A diffused monitor function isused to ensure high quality meshes near the interface. Several numerical experimentsare carried out to demonstrate the effectiveness of the moving mesh strategy.

关键词： Moving finite-element method two-phase flow viscoelastic flow non-newtonian flow

nonlinear property of the visco-elastic-plastic material in the impact problem

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Journal of Shanghai University(English Edition) 2009年第1期13卷 23-28页

作者：侯磊蔡立 Department of Mathematics College of SciencesShanghai University Division of Computational Science E-Institutes of Shanghai UniversitiesShanghai Jiaotong University

In this paper a numerical investigation on the non-newtonian flow problem is conducted, in order to shed further light on the mathematical and virtual test methods in the auto-crash safety analysis. The accurate mathe... 详细信息

关键词： non-newtonian flow impact boundary layer perturbation semi-discrete Galerkin form