Home / Advanced Search

  • Title/Keywords

  • Author/Affliations

  • Journal

  • Article Type

  • Start Year

  • End Year

Update SearchingClear
  • Articles
  • Online
Search Results (190)
  • Open Access

    ARTICLE

    Numerical Study of Double Diffusive Convection in presence of Radiating Gas in a Square Cavity

    F. Moufekkir1, M.A. Moussaoui1, A. Mezrhab1,2, H. Naji3,4, M. Bouzidi5

    FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.2, pp. 129-154, 2012, DOI:10.3970/fdmp.2012.008.129

    Abstract The problem related to coupled double diffusive convection in a square enclosure filled with a gray gas in the presence of volumetric radiation is examined numerically. The horizontal walls are assumed to be insulated and impermeable. Different temperatures and species concentrations are imposed at vertical walls. In particular, we propose a 2-D numerical approach based on a hybrid scheme combining a multiple-relaxation-time lattice Boltzmann model (MRT-LBM) and a standard finite difference method (FDM). The radiative term in the energy equation is treated using the discrete ordinates method (DOM) with a S8 quadrature. The influence of… More >

  • Open Access

    ARTICLE

    HEAT TRANSFER IN A MICROTUBE OR MICROCHANNEL WITH PROTRUSIONS

    Muhammad M. Rahman*, Phaninder Injeti

    Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-9, 2011, DOI:10.5098/hmt.v2.1.3003

    Abstract This paper presents the effects of protrusions on heat transfer in a microtube and in a two-dimensional microchannel of finite wall thickness. The effects of protrusion shape, size, and number were investigated. Calculations were done for incompressible flow of a Newtonian fluid with developing momentum and thermal boundary layers under uniform and discrete heating conditions. It was found that the local Nusselt number near a protrusion changes significantly with the variations of Reynolds number, height, width, and distance between protrusions, and the distribution of discrete heat sources. The results presented in the paper demonstrate that More >

  • Open Access

    ABSTRACT

    Discrete Lattice Modeling of Atomistic Locations in the Interfaces Between Nanomaterials

    V.K. Tewary

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 113-114, 2011, DOI:10.3970/icces.2011.019.113

    Abstract Interfacial region between two nanomaterials can be treated as a separate material since its atomistic structure and characteristics are different than the two materials on its either side. The mechanical as well as electronic properties of composite materials are sensitive to the interfaces. For industrial application of the nanomaterial systems, it is vital to model and measure the discrete atomistic locations in the interface during operating conditions. As the dimensions of nanomaterial systems shrink, the role of interfaces become increasingly important. Because of its nanothickness, the conventional characterization and design parameters like elastic constants, stress… More >

  • Open Access

    ABSTRACT

    Face stability of shallow shield tunnels in dry sandy ground: model tests, discrete element method simulations and theoretical model

    Renpeng Chen, Linggang kong, Lvjun Tang, Yunmin Chen

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 99-100, 2011, DOI:10.3970/icces.2011.020.099

    Abstract Face stability is critical in the underground tunneling. In this report, large-scale model tests on the face stability of shallow tunnels for various cover depths (C/D = 0.5, 1, and 2) in dry sandy ground were firstly introduced. Then, a series of three-dimensional DEM models were built to simulated the process of tunnel face failure. The results of the model tests and DEM simulations reveal that a chimney like failure zone appears during the tunnel face failure. It was founded that with the increase of the horizontal displacement of the tunnel face, the support pressure More >

  • Open Access

    ABSTRACT

    A New Combined Scheme of Discrete Element Method and Meshless Method for Numerical Simulation of Impact Problems

    Li Shan, Ming Cheng, Kaixin Liu

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.019.087

    Abstract In the present paper, a combined scheme of discrete element method (DEM) and meshless method for numerical simulation of impact problems is proposed. Based on the basic principle of continuum mechanics, an axisymmetric DEM framework is estabilished for modeling the elastoplastic behavior of solid materials. A failure criterion is introduced to model the transformation from a continuum to a discontinuum. The friction force between contact elements is also considered after the failure appears. So our scheme can calculate not only the behavior of continuum and discontinuum, but also the transformation process from continuum to discontinuum. More >

  • Open Access

    ARTICLE

    Strength of Brittle Materials under High Strain Rates in DEM Simulations

    Jorge Daniel Riera1, Letícia Fleck Fadel Miguel2, Ignacio Iturrioz3

    CMES-Computer Modeling in Engineering & Sciences, Vol.82, No.2, pp. 113-136, 2011, DOI:10.32604/cmes.2011.082.113

    Abstract In the truss-like Discrete Element Method (DEM), masses are considered lumped at nodal points and interconnected by means of uni-dimensional elements with arbitrary constitutive relations. In previous studies of the tensile fracture behavior of concrete cubic samples, it was verified that numerical predictions of fracture of non-homogeneous materials using DEM models are feasible and yield results that are consistent with the experimental evidence so far available. Applications that demand the use of large elements, in which extensive cracking within the elements of the model may be expected, require the consideration of the increase with size… More >

  • Open Access

    ARTICLE

    A simple locking-free discrete shear triangular plate element

    Y.C. Cai1,2,3, L.G. Tian1, S.N. Atluri3

    CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.3&4, pp. 221-238, 2011, DOI:10.3970/cmes.2011.077.221

    Abstract A new three node triangular plate element, labeled here as DST-S6 (Discrete Shear Triangular element with 6 extra Shear degrees of freedom), is proposed for the analyses of plate/shell structures comprising of thin or thick members. The formulation is based on the DKT (Discrete Kirchhoff Technique) and an appropriate use of the independent shear DOF(Degrees Of Freedom). The shear locking is completely eliminated in the DST-S6, without any numerical expediencies such as the reduce integration, the use of assumed strains/stresses, or the need for the stabilization of the attendant zero energy modes. It is shown… More >

  • Open Access

    ARTICLE

    A New Discrete-Layer Finite Element for Electromechanically Coupled Analyses of Piezoelectric Adaptive Composite Structures

    M. Al-Ajmi1, A. Benjeddou2

    CMC-Computers, Materials & Continua, Vol.23, No.3, pp. 265-286, 2011, DOI:10.3970/cmc.2011.023.265

    Abstract A new discrete layer finite element (DLFE) is presented for electro-mechanically coupled analyses of moderately thick piezoelectric adaptive composite plates. The retained kinematics is based on layer-wise first-order shear deformation theory, and considers the plies top and bottom surfaces in-plane displacements and the plate transverse deflection as mechanical unknowns. The former are assumed in-plane Lagrange linear, while the latter is assumed in-plane full (Lagrange) quadratic; this results in a nine nodes quadrangular (Q9) DLFE. The latter is validated in free-vibrations, first numerically against ANSYS three-dimensional piezoelectric finite elements for a cantilever moderately thick aluminum plate… More >

  • Open Access

    ARTICLE

    Algebraic Formulation of Elastodynamics: the Cell Method

    E. Tonti, F. Zarantonello1

    CMES-Computer Modeling in Engineering & Sciences, Vol.64, No.1, pp. 37-70, 2010, DOI:10.3970/cmes.2010.064.037

    Abstract This paper completes a preceeding paper on the algebraic formulation of elastostatics [Tonti, Zarantonello (2009)]. It shows how to obtain a numerical formulation for elastodynamics by avoiding any process of discretization of differential equations, i.e. PDE-free formulation. To this end, we must analyse in more detail the discretization of time by highlighting the need to introduce a dual subdivision of the time axis, as we did for a space cell complex. The mass matrix obtained with the direct algebraic formulation is diagonal. More >

  • Open Access

    ABSTRACT

    Sampling-reconstruction procedure of discrete Markov processes with continuous time

    Yu.A. Goritskiy1, V.A. Kazakov2

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.2, pp. 63-64, 2010, DOI:10.3970/icces.2010.014.063

    Abstract At the first time the statistical description of the Sampling-Reconstruction Procedure (SRP) of Discrete Markov Processes (Markov chains) with continuous time and with an arbitrary number of states is given. The mathematical models of Markov chains with continuous time are intensively used in the description of some real stochastic processes with jumps (in control systems and radio engineering), for instance, impulse noise [1, 2]. This is the reason that it is necessary to know: how to sample, how to reconstruct and how to calculate the reconstruction errors of such processes. (Jumps can be occurred in More >

Displaying 151-160 on page 16 of 190. Per Page