X. X. Cui¹, X. Zhang^1,2, X. Zhou³, Y. Liu¹, F. Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.6, pp. 565-599, 2014, DOI:10.3970/cmes.2014.098.565

Abstract The material point method (MPM) discretizes the material domain by a set of particles, and has showed advantages over the mesh-based methods for many challenging problems associated with large deformation. However, at the same time, it requires more computational resource and has difficulties to construct high order scheme when simulating the fluid in high explosive (HE) explosion problems. A coupled finite difference material point (CFDMP) method is proposed through a bridge region to combine the advantages of the finite difference method (FDM) and MPM. It solves a 3D HE explosion and its interaction with the… More >

R.A. Regueiro^1,2, B. Zhang², S.L. Wozniak³

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 1-39, 2014, DOI:10.3970/cmes.2014.098.001

Abstract The paper presents three-dimensional, large deformation, coupled finite element analysis (FEA) of dynamic loading on soft biological tissues treated as biphasic (solid-fluid) porous media. An overview is presented of the biphasic solidfluid mixture theory at finite strain, including inertia terms. The solid skeleton is modeled as an isotropic, compressible, hyperelastic material. FEA simulations include: (1) compressive uniaxial strain loading on a column of lung parenchyma with either pore air or water fluid, (2) out-of-plane pressure loading on a thin slab of lung parenchyma with either pore air or water fluid, and (3) pressure loading on More >

Xiaolin Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.6, pp. 483-507, 2014, DOI:10.3970/cmes.2014.097.483

Abstract Combining moving least square (MLS) approximations and boundary integral equations, a symmetric and boundary-only meshless method, the Galerkin boundary node method (GBNM), is developed in this paper for two- and threedimensional elasticity problems with mixed boundary conditions. Unlike other MLS-based meshless methods, boundary conditions in this meshless method can be applied directly and easily. In the GBNM, the stiffness matrices so obtained are symmetric. The property of symmetry is an added advantage in coupling the GBNM with the finite element method (FEM). Thus, a symmetric coupling of the GBNM and the FEM is also discussed More >

A. Roychowdhury^1,2, A. Nandy¹, C.S. Jog¹, R. Pratap^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.103, No.2, pp. 91-110, 2014, DOI:10.3970/cmes.2014.103.091

Abstract We present a hybrid finite element based methodology to solve the coupled fluid structure problem of squeeze film effects in vibratory MEMS devices, such as gyroscopes, RF switches, and 2D resonators. The aforementioned devices often have a thin plate like structure vibrating normally to a fixed substrate, and are generally not perfectly vacuum packed. This results in a thin air film being trapped between the vibrating plate and the fixed substrate which behaves like a squeeze film offering both stiffness and damping. For accurate modelling of such devices the squeeze film effects must be incorporated.… More >

D. Ishihara¹, T. Horie¹

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.6, pp. 421-440, 2014, DOI:10.3970/cmes.2014.101.421

Abstract In this study, a projection method for the monolithic interaction system of an incompressible fluid and a structure using a new algebraic splitting is proposed. The proposed method splits the monolithic equation system into the equilibrium equations and the pressure Poisson equation (PPE) algebraically using the intermediate velocity in the nonlinear iterations. Since the proposed equilibrium equation satisfies the interface condition, the proposed method is strongly coupled. Moreover, the proposed PPE enforces the incompressibility constraint. Different from previous studies, the proposed algebraic splitting never generates any Schur complement. The proposed method is applied to a More >

N. Mitsume¹, S. Yoshimura¹, K. Murotani¹, T. Yamada¹

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.4, pp. 229-247, 2014, DOI:10.3970/cmes.2014.101.229

Abstract The MPS-FE method, which adopts the Finite Element (FE) method for structure computation and the Moving Particle Simulation (MPS) method for fluid computation involving free surfaces, was developed to solve fluid-structure interaction problems with free surfaces. The conventional MPS-FE method, in which MPS wall boundary particles and finite elements are overlapped in order to exchange information at a fluid-structure interface, is not versatile and reduces the advantages of the software modularity. In this study, we developed a nonoverlapping approach in which the interface in the fluid computation corresponds to the interface in the structure computation More >

S.A. Khuri¹, A. Sayfy¹

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.2, pp. 81-96, 2014, DOI:10.3970/cmes.2014.101.081

Abstract In this article, we introduce a numerical scheme to solve a class of nonlinear two-point BVPs on a semi-infinite domain that arise in engineering applications and the physical sciences. The strategy is based on replacing the boundary condition at infinity by an asymptotic boundary condition (ABC) specified over a finite interval that approaches the given value at infinity. Then, the problem complimented with the resulting ABC is solved using a fourth order spline collocation approach constructed over uniform meshes on the truncated domain. A number of test examples are considered to confirm the accuracy, efficient More >

M. Dehghan¹, M. Abbaszadeh², A. Mohebbi³

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.5, pp. 399-444, 2014, DOI:10.3970/cmes.2014.100.399

Abstract In this paper three numerical techniques are proposed for solving the system of N-coupled nonlinear Schrödinger (CNLS) equations. Firstly, we obtain a time discrete scheme by approximating the first-order time derivative via the forward finite difference formula, then for obtaining a full discretization scheme, we use the Kansa’s approach to approximate the spatial derivatives via radial basis functions (RBFs) collocation methodology. We introduce the moving least squares (MLS) approximation and radial point interpolation method (RPIM) with their shape functions, separately. It should be noted that the shape functions of RPIM unlike the shape functions of the… More >

Mustapha Faraji¹, El Alami Mustapha, Najam Mostafa

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 279-298, 2014, DOI:10.3970/fdmp.2014.010.279

Abstract A study is reported of heat transfer and melting in a fan-less thermal management system consisting of an insulated horizontal cavity filled with a phase change material (PCM) and heated from below by a conducting plate supporting three identical protruding heat sources. Such a PCM enclosure can be used as a heat sink for the cooling of electronic components. The advantage of this cooling strategy is that PCMs characterized by high energy storage density and small transition temperature interval, are able to store a high amount of heat (thereby providing efficient passive cooling). A two-dimensional More >

Imen Mejri^1,2, Ahmed Mahmoudi¹, Mohamed Ammar Abbassi¹, Ahmed Omri¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 83-114, 2014, DOI:10.3970/fdmp.2014.010.083

Abstract This study examines natural convection in a square enclosure filled with a water-Al₂O₃ nanofluid and subjected to a magnetic field. The side walls of the cavity have spatially varying sinusoidal temperature distributions. The horizontal walls are adiabatic. A Lattice Boltzmann method (LBM) is applied to solve the governing equations for fluid velocity and temperature. The following parameters and related ranges are considered: Rayleigh number of the base fluid, from Ra=10³ to 10⁶, Hartmann number from Ha=0 to 90, phase deviation (γ =0, π/4, π/2, 3π/4 and π) and solid volume fraction of the nanoparticles between ø = 0 and More >