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Applied Mathematics and Mechanics(English Edition) 2003年第2期24卷 138-152页

作者：黄义张引科 ScienceCollegeXi’anUniversityofArchitecture&Technology

The linear constitutive equations and field equations of unsaturated soils were obtained through linearizing the nonlinear equations given in the first part of this work. The linear equations were expressed in the forms similar to Biot's equations for saturated porous media. The Darcy's laws of unsaturated soil were proved. It is shown that Biot's equations of saturated porous media are the simplification of the theory. All these illustrate that constructing constitutive relation of unsaturated soil on the base of mixture theory is rational.

关键词： mixture theory unsaturated soil linear constitutive equation linear field equation Darcy's law Biot's equations

Simulation of submerged granular flows by development of a twophase incompressible explicit mesh-free method

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International Journal of Sediment Research 2023年第4期38卷 530-542页

作者： Tibing Xu Shuangke Sun Peng Wu State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower Research School of Civil & Environmental Engineering and Geography Science Ningbo University Faculty of Engineering and Applied Science University of Regina

The interaction between fluid and sediment particles is widely involved in hydraulic engineering problems. In the current study, an explicit incompressible mesh-free method in the framework of the Moving Particle Semi-implicit(MPS) method is proposed to simulate the interaction between the two phases in submerged conditions. The proposed method solves two sets of the continuity and momentum equations, respectively, for the fluid phase and the sediment phase according to the mixture theory. In the method, the pressure and velocity fields are explicitly calculated for the sediment phase with the solid concentration obtained from the mixture theory, in which a rheology model is used to account for the viscosity and shear stress. The governing equations for the fluid are solved using the predictor-corrector time-splitting scheme and the resulting Poisson equation for pressure is calculated using an explicit scheme. In each loop, the discretized points move according to the velocity of the fluid in the mesh-free Lagrangian approach. The proposed method is used to simulate the submerged granular flows including submerged granular column collapse, submerged granular sliding on slopes, and erodible dambreak flow. In the simulations, the parameters of particle distance and collision distance in the numerical method are investigated. It is found that the flow characteristics in the granular flows are reflected by the proposed method and the simulated free surface and water-sediment interface profiles are in good agreement with experimental observations.

关键词： Mesh-free method Explicit method mixture theory Sediment transport Water-sediment interface

ELECTROHYDRODYNAMIC DISPERSION OF DEFORMABLE AEROSOLS IN THE PRESENCE OF AN ELECTRIC FIELD AND CHEMICAL REACTION USING TAYLOR DISPERSION MODEL

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Journal of Hydrodynamics 2011年第2期23卷 247-257页

作者： RUDRAIAH N. DEVARAJU N. NG Chiu-On UGC-CAS in Fluid Mechanics Department of Mathematics Bangalore University Bangalore-560 001 India National Research Institute for Applied Mathematics (NRIAM) Bangalore-560 070 India Department of Mechanical Engineering The University of Hong Kong

Under the effects of electric field and chemical reaction, the problem of dispersion of aerosols in a poorly conducting fluid in a channel is solved analytically using the mixture theory together with a regular perturbation technique. It is shown that the aerosols are dispersed relative to a plane moving with the mean speed of atmospheric fluid as well as the mean speed of agglomeration of aerosol with a relative diffusion coefficient, called the Taylor dispersion coefficient. This coefficient is numerically computed and the results reveal that it increases with an increase in the electric number, but decreases with increasing porous parameter. The physical explanations for the phenomena are given in this article.

关键词： dispersion aerosols electrohydrodynamics mixture theory

Bi-phasic Simulation of Metal Injection Moulding:Constitutive Determinations

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Journal of Southwest Jiaotong University(English Edition) 2003年第2期11卷 122-130页

作者：柳葆生 Barriere Thierry Gelin Jean-Claude Department of Engineering Mechanics Southwest Jiaotong University LMARC Franche-Comt University

To predict the segregation effect in metal injection moulding (MIM) injection, a bi-phasic model based on mixture theory is adopted in simulation. An explicit algorithm is developed and realized by the authors, which conducts the simulation to be a cost-effective tool in MIM technology. In case of the bi-phasic simulation, the viscosity behaviours are necessary to be determined for the flows of each phase while only the viscosity of mixture is measurable by tests. It is a crucial problem for application of the bi-phasic simulation of MIM injection. A reasonable method is hence analysed and proposed to determine the viscosity behaviours of each phase. Even though this method may be furthermore modified in the future, it results in the practical simulation of segregation effects with reasonable parameters. The simulation results are compared with the measurements on injected specimens.

关键词： metal injection moulding bi-phasic simulation viscous behaviours mixture theory

The Kinematics and Field Equations for Porous Media

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Journal of Modern Transportation 1999年第1期16卷 44-55页

作者：陆宏轮 Department of Underground Engineering and Geotechnical Engineering Southwest Jiaotong University Chengdu 610031 China

With a porous medium regarded as an immiscible mixture of multiphase and each phase as a miscible mixture of multi constituent, a systematical research on the kinematics and field equations for porous media is carried out from the point of view of mixture theory. It is shown that the motion of each phase is the mathematical average of the motions of all constituents in the phase, and that the motion of porous media may be described as the motion of the skeleton and the relative motion of each phase with respect to the skeleton. The influence of mass exchange between different constituents in each phase and the influence of mass exchange of same constituent between different phases in porous media are considered in field equations which are self consistent in theory. All the field equations in the references are special cases of the equations proposed in this paper.

关键词： kinematics field equations mixture theory porous media