N. Thai-Quang¹, N. Mai-Duy¹, C.-D. Tran¹, T. Tran-Cong^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.96, No.1, pp. 49-90, 2013, DOI:10.3970/cmes.2013.096.049

Abstract In this paper, we present a numerical scheme, based on the direct forcing immersed boundary (DFIB) approach and compact integrated radial basis function (CIRBF) approximations, for solving the Navier-Stokes equations in two dimensions. The problem domain of complicated shape is embedded in a Cartesian grid containing Eulerian nodes. Non-slip conditions on the inner boundaries, represented by Lagrangian nodes, are imposed by means of the DFIB method, in which a smoothed version of the discrete delta functions is utilised to transfer the physical quantities between two types of nodes. The velocities and pressure variables are approximated More >

R.H. Haney¹, R.V. Mohan²

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.5, pp. 431-452, 2013, DOI:10.3970/cmes.2013.095.431

Abstract The use of Graphics Processing Units (GPUs) as co-processors for single CPU/GPU computing systems has become pronounced in high performance computing research, however the solution of truly large scale computationally intensive problems require the utilization of multiple computing nodes. Multiple CPU/GPU computing systems bring new complexities to the observed performance of computationally intensive applications, the more salient of which is the cost of local CPU-GPU host and intra-nodal communication. This paper compares and analyzes the performance of a computationally intensive application represented by resin infusion flow during liquid composite molding process for the manufacture of… More >

H.T. Liu^1,2, Z. Chen², S. Jiang², Y. Gan³, M.B. Liu⁴, J.Z. Chang¹, Z.H. Tong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.4, pp. 303-315, 2013, DOI:10.3970/cmes.2013.095.303

Abstract Dissipative particle dynamics (DPD) and molecular dynamics (MD) are both Lagrangian particle-based methods with similar equations except that the DPD specification for the force definition on the particles is the result of coarsegraining, and these two methods usually get the similar results in some specific cases. However, there are still some unknown differences between them. Considering the water response to external force, a comparative study of DPD and MD is conducted in this paper, which provides a better understanding on their relation, and a potential way to effectively bridge nanoscale and mesoscale simulation procedures. It More >

Bing Li^1,2, Zhengjia He¹

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.4, pp. 293-316, 2013, DOI:10.3970/cmes.2013.093.293

Abstract The vibration-based crack identification problem insists of finding a measured vibration parameter from a complete crack-detection-database constructed by numerical simulation. It is one of the classical optimization problems. Many intelligence methods, such as neural network (NN), genetic algorithm (GA), determinant transformation (DT), and frequency contour (FC) etc., have been extensively employed as optimization tools to achieve this task. The aim of this paper is to propose a benchmark problem to compare these extensive-used optimization methods in terms of crack identification precision and computational time. The merit and demerits for each method are discussed. The results More >

A.V. Ekhlakov^1,2, O.M. Khay^1,3, Ch. Zhang¹, X.W. Gao⁴, J. Sladek⁵, V. Sladek⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.6, pp. 595-614, 2013, DOI:10.3970/cmes.2013.092.595

Abstract A boundary-domain integral equation method is applied to the transient thermoelastic crack analysis in functionally graded materials. Fundamental solutions for homogeneous, isotropic and linear elastic materials are used to derive the boundary-domain integral equations. The radial integration method, the Cartesian transformation method and the cell-integration method are applied for the evaluation of the arising domain-integrals. Numerical results for dynamic stress intensity factors obtained by the three approaches are presented, compared and discussed to show the accuracy and the efficiency of the domain-integral evaluation techniques. More >

Smitha Gopinath¹, C.K. Madheswaran¹, A. Rama Ch,ra Murthy¹, Nagesh. R. Iyer², Barkavi.T³

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.2, pp. 151-172, 2013, DOI:10.3970/cmes.2013.092.151

Abstract This paper presents the details of experimental and numerical investigations performed on fabric reinforced concrete (FABcrete) panels under impact loading. Experimental investigations have been carried out using drop weight impact on a square FABcrete panel to study the damage, failure mode and acceleration. The drop weight of 20 kg is used for the study and drop heights have been varied as 100mm, 200mm and 300mm. Numerical simulation of the drop weight impact tests on FABcrete panels have been carried out and observed that there is a good correlation between experimental and numerical predictions. It is More >

N. Pham-Sy¹, C.-D. Tran¹, T.-T. Hoang-Trieu¹, N. Mai-Duy¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.1, pp. 1-31, 2013, DOI:10.3970/cmes.2013.092.001

Abstract Compact Local Integrated Radial Basis Function (CLIRBF) methods based on Cartesian grids can be effective numerical methods for solving partial differential equations (PDEs) for fluid flow problems. The combination of the domain decomposition method and function approximation using CLIRBF methods yields an effective coarse-grained parallel processing approach. This approach has enabled not only each sub-domain in the original analysis domain to be discretised by a separate CLIRBF network but also compact local stencils to be independently treated. The present algorithm, namely parallel CLIRBF, achieves higher throughput in solving large scale problems by, firstly, parallel processing More >

T.-T. Hoang-Trieu¹, N. Mai-Duy¹, C.-D. Tran¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.91, No.6, pp. 485-516, 2013, DOI:10.3970/cmes.2013.091.485

Abstract In this paper, compact local integrated radial basis function (IRBF) stencils reported in [Mai-Duy and Tran-Cong (2011) Journal of Computational Physics 230(12), 4772-4794] are introduced into the finite-volume / subregion - collocation formulation for the discretisation of second-order differential problems defined on rectangular and non-rectangular domains. The problem domain is simply represented by a Cartesian grid, over which overlapping compact local IRBF stencils are utilised to approximate the field variable and its derivatives. The governing differential equation is integrated over non-overlapping control volumes associated with grid nodes, and the divergence theorem is then applied to More >

Byung-Hyuk Lee¹, Se-min Jeong², Sung-Chul Hwang², Jong-Chun Park³, Moo-Hyun Kim⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.91, No.1, pp. 43-63, 2013, DOI:10.3970/cmes.2013.091.043

Abstract The violent free-surface motions interacting with floating vessels containing inner liquid tanks are investigated by using the newly developed Moving Particle Semi-implicit (MPS) method for 2-dimensional incompressible flow simulation. In the present numerical examples, many efficient and robust algorithms have been developed and applied to improve the overall quality and efficiency in solving various highly nonlinear free-surface problems and evaluating impact pressures compared to the original MPS method proposed by Koshizuka and Oka (1996). For illustration, the improved MPS method is applied to the simulation of nonlinear floating-body motions, violent sloshing motions and corresponding impact More >

Payam Sharifi¹, Asghar Esmaeeli²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.4, pp. 389-418, 2013, DOI:10.3970/fdmp.2013.009.389

Abstract This study aims to explore the effect of liquid film thickness on the electrohydrodynamic-driven instability of the interface separating two horizontal immiscible liquid layers. The fluids are confined between two electrodes and the light and less conducting liquid is overlaid on the heavy and more conducting one. Direct Numerical Simulations (DNSs) are performed using a front tracking/finite difference scheme in conjunction with Taylor-Melcher leaky dielectric model. For the range of physical parameters used here, it is shown that for a moderately thick lower liquid layer, the interface instability leads to formation of several liquid columns… More >