B. Šavija¹, E. Schlangen¹

CMC-Computers, Materials & Continua, Vol.48, No.3, pp. 181-202, 2015, DOI:10.3970/cmc.2015.048.181

Abstract In this paper, a novel approach for simulating in-plane vibration of thin plates is proposed. It is based on the spectral element method (SEM) used within a lattice modeling framework. First, derivation of a frequency dependent dynamic stiffness matrix for a spectral beam element is presented. Then, the lattice modeling concept is introduced. In the model, the two-dimensional plate is discretized as a set of (one dimensional) spectral beam elements connected at the ends. The proposed approach is then used for modal analysis of rectangular plates of different aspect ratios (1 and 2) and boundary conditions (completely free and clamped).… More >

N. Sukumar¹, J. E. Bolander¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.6, pp. 691-706, 2003, DOI:10.3970/cmes.2003.004.691

Abstract In this paper, we explore the numerical approximation of discrete differential operators on non-uniform grids. The Voronoi cell and the notion of natural neighbors are used to approximate the Laplacian and the gradient operator on irregular grids. The underlying weight measure used in the numerical computations is the {\em Laplace weight function}, which has been previously adopted in meshless Galerkin methods. We develop a difference approximation for the diffusion operator on irregular grids, and present numerical solutions for the Poisson equation. On regular grids, the discrete Laplacian is shown to reduce to the classical finite difference scheme. Two techniques to… More >

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 and strains are not reliable… More >

Masato Yoshino, Yoshito Tanaka, Keisuke Yano

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 131-132, 2011, DOI:10.3970/icces.2011.018.131

Abstract Dynamics of droplet impact on solid surfaces is of great importance in many engineering applications such as ink-jet printing and rapid spray cooling of hot surfaces. In this study, the lattice kinetic scheme based on the lattice Boltzmann method for immiscible two-phase fluids [Inamuro (2006)] is applied to such micro-fluid problems. The present method enables us to perform stable calculations of two-phase flows with large density ratios of up to 1000. The boundary condition based on the wetting potential that is calculated according to a prescribed static contact angle is used on solid surfaces [Briant, Papatzacos, and Yeomans (2002)]. First,… More >

K. Suga, T. Ito

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 99-100, 2011, DOI:10.3970/icces.2011.018.099

Abstract Evaluation and optimization of the multiple-relaxation-time (MRT) lattice Boltzmann method for micro-flows (micro-flow LBM) are performed with the two-dimensional nine discrete velocity (D2Q9) model. The MRT micro-flow LBM consisting of the combination of bounce-back and full diffusive (CBBFD) wall boundary condition is considered. Based on the discussion of Chai et al. (2010), the presently applied CBBFD model and relaxation time for heat flux satisfy the second-order slip boundary condition. However, modification to the MRT model of Chai et al. (MRT-C) is made to the relaxation time for the moments related to the stress by introducing the psi function (Stops,1970; Guo… More >

Yohei Inoue, Taishi Nakamura, Shuji Ogata, Ryo Kobayashi, Toshiyuki Gotoh

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 49-50, 2011, DOI:10.3970/icces.2011.020.049

Abstract No proper simulation method exists in between the molecular simulation method at nanometer scale using the first principles or empirical inter-molecular interaction and the continuum simulation method at micrometer-plus scale. The nanotechnology deals principally with those systems whose characteristic scales reside in such a scale-gap. Considering this, we develop a sequential scale-up scheme starting from the atomistic up to micrometer-plus scales. In the present paper we take, as an example, the system of graphenes that may or may not be fluttering in airflow, and apply to it our sequential scale-up scheme to see its capability.

The graphene is unique… More >

Anjie Hu*, DongLiu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.3, pp. 160-160, 2019, DOI:10.32604/icces.2019.05466

Abstract The pseudo-potential lattice Boltzmann (LB) phase change model has been widely applied in the simulation of liquid-vapor phase change problem. In the simulation, the LB method are applied in modeling of both two-phase flow and the energy transition. However, Li et al. [Physical Reviews E 96, 063303 (2017)] pointed out that the LB thermal equations cause errors when applied with pseudo-potential model. To eliminate these errors, they proposed an improved model by adding correction terms in the LB thermal equation. In their research, the treatment of these correction terms is quite complex and several finite-difference (FD) computations are adopted to… More >

Somchai Sriyab¹, Wannapong Triampo²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.3, pp. 51-52, 2009, DOI:10.3970/icces.2009.013.051

Abstract Understanding of Bacteria cell division is essential for an understanding of microorganism as well as the origin of the life. Particularly, in cell division process of \emph {E. coli}, Min proteins (MinD and MinE) play crucial roles to regulate the dividing dynamics physically via their oscillatory dynamics from pole to pole. In this work, we have developed a numerical scheme based on the mesoscopic Lattice Boltzmann Method (LBM) to simulate the coarse-grained coupled reaction-diffusion equations model used to describe the MinD/MinE interaction in two dimensions. Biologically, we have focused on investigating how the protein copies affect the oscillation patterns as… More >

Waipot Ngamsaad, Wannapong Triampo¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.2, pp. 49-50, 2009, DOI:10.3970/icces.2009.013.049

Abstract The Min-proteins oscillation in \emph {E. coli} has an essential role in controlling the accuracy placement of cell-division septum at the middle cell zone of the bacteria. This biochemical process has been successfully described by a set of reaction-diffusion equation at the macroscopic level [1]. Recently, a mesoscopic modeling by the lattice Boltzmann method (LBM) has been proposed to simulate the Min-proteins oscillation [2]. However, as pointed out by Zhang et al., the standard boundary conditions are not accuracy for a class of dispersion transport modeled by LBM [3]. In this present work, we investigated the boundary effects in LBM… More >

B.K. Raghu Prasad¹, T.V.R.L. Rao¹, A.R.Gopalakrishnan¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.2, pp. 99-112, 2008, DOI:10.3970/icces.2008.006.099

Abstract A modified lattice model using finite element method has been developed to study the mode-I fracture analysis of heterogeneous materials like concrete. In this model, the truss members always join at points where aggregates are located which are modeled as plane stress triangular elements. The truss members are given the properties of cement mortar matrix randomly, so as to represent the randomness of strength in concrete. It is widely accepted that the fracture of concrete structures should not be based on strength criterion alone, but should be coupled with energy criterion. Here, by incorporating the strain softening through a parameter… More >