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 structural composites application via two… More >

S. Brischetto¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.5, pp. 391-430, 2013, DOI:10.3970/cmes.2013.095.391

Abstract This paper gives an exact three-dimensional elastic model for the free vibration analysis of functionally graded one-layered and sandwich simply-supported plates and shells. An exact elasticity solution is proposed for the differential equations of equilibrium written in general orthogonal curvilinear coordinates. The equations consider a geometry for shells without simplifications, and allow the analysis of the cases of spherical shell panels, cylindrical shell panels, cylindrical closed shells and plates. The main novelty is the possibility of a general formulation for these geometries. The coefficients in equilibrium equations depend on the thickness coordinate because of the radii of curvature for the… More >

T.W. Dong¹, H.S. Liu¹, S.L. Jiang², L.Gu¹, Q.W. Xiao¹, Z. Yu¹, X.F. Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.5, pp. 369-390, 2013, DOI:10.3970/cmes.2013.095.369

Abstract In this paper, we present a free surface flow model with a forced revolving moving boundary for partially filled screw extrusion. The incompressible smoothed particle hydrodynamics (ISPH) is used to simulate this complex flow. A set of organic glass experimental device for this partially filled fluid is manufactured. SPH results are satisfactorily compared with experiment results. The computed free surfaces are in good agreement with the free surfaces obtained from the experiment. Further analysis shows that with the increase of the speed, the average velocity of fluid increases, the effect of centrifugal force begin to show up, the maximum pressure… More >

K. Kakuda¹, K. Tochikubo¹, J. Toyotani¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.5, pp. 351-367, 2013, DOI:10.3970/cmes.2013.095.351

Abstract The application of a CPU/GPU-based particle method to dam-breaking incompressible viscous fluid flow problems is presented. The particle approach is based on the MPS (Moving Particle Semi-implicit) scheme using logarithmic weighting function to stabilize the spurious oscillatory solutions for solving the Poisson equation with respect to the pressure fields by using GPU-based SCG (Scaled Conjugate Gradient) method. The physics-based computer graphics for the results of three-dimensional simulation consist of the POV-Ray (Persistence of Vision Raytracer) rendering using marching cubes algorithm as polygonization. Numerical results demonstrate the workability and the validity of the present approach through the dam-breaking flow problem. More >

M. G. He¹, C.L. Tan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.4, pp. 317-349, 2013, DOI:10.3970/cmes.2013.095.315

Abstract The self-regularization technique in the Boundary Element Method (BEM) originally proposed by Cruse and Richardson (1996, 1999) in their work for two-dimensional (2-D) stress analysis is extended to three-dimensional (3-D) elastostatics in this paper. The regularization scheme addresses the issue of accurate numerical evaluation of the integrals due to the singularity of the kernel functions of the integral equations. It is first implemented for the determination of displacements and stresses at interior points of the solution domain, and very accurate results are obtained even when these points are very close to the surface of the domain. A self-regularized traction-BIE is… 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 is shown that there is… More >

Ashraf Balabel¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.4, pp. 283-302, 2013, DOI:10.3970/cmes.2013.095.283

Abstract This paper presents the numerical results obtained from the numerical simulation of turbulent liquid jet atomization due to three distinctly different types of liquid jets/air orientations; namely, coflow jet, coaxial jet and the combined coflow-coaxial jet. The applied numerical method, developed by the present authors, is based on the solution of the Reynolds-Averaged Navier Stokes (RANS) equations for time-dependent, axisymmetric and incompressible two-phase flow in both phases separately and on regular and structured cell-centered collocated grids using the control volume approach. The transition from one phase to another is performed through a consistent balance of the interfacial dynamic and kinematic… More >

Ahmad Shirzadi¹, Vladimir Sladek², Jan Sladek³

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.4, pp. 259-282, 2013, DOI:10.3970/cmes.2013.095.259

Abstract This paper is concerned with the development of a numerical approach based on the Meshless Local Petrov-Galerkin (MLPG) method for the approximate solutions of the two dimensional nonlinear reaction-diffusion Brusselator systems. The method uses finite differences for discretizing the time variable and the moving least squares (MLS) approximation for field variables. The application of the weak formulation with the Heaviside type test functions supported on local subdomains (around the nodes used in MLS approximation) to semi-discretized partial differential equations yields the finite-volume local weak formulation. A predictor-corrector scheme is used to handle the nonlinearity of the problem within each time… More >

L. Sun¹, G. Yang², Q. Zhang³

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.3, pp. 235-258, 2013, DOI:10.3970/cmes.2013.095.234

Abstract We propose numerical integration rules for meshless local Petrov- Galerkin methods (MLPG) employed to solve elliptic partial different equations (PDE) with Neumann boundary conditions. The integration rules are required to satisfy an integration constraint condition of Green’s formula type (GIC). GIC was first developed in [Babuska, Banerjee, Osborn, and Zhang (2009)] for Galerkin meshless method, and we will show in this paper that it has better features for MLPG due to flexibility of MLPG in choosing different trial and test function spaces. A general constructive algorithm is presented to design the integration rules satisfying GIC. We also present a useful… More >

Haitao Liao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.3, pp. 207-234, 2013, DOI:10.3970/cmes.2013.095.207

Abstract The constrained optimization multi-dimensional harmonic balance method for calculating the quasi-periodic solutions of nonlinear systems is presented. The problem of determining the worst quasi-periodic response is transformed into a nonlinear optimization problem with nonlinear equality constraints. The general nonlinear equality constraints are built using a set of nonlinear algebraic equations which is derived using the multi-dimensional harmonic balance method. The Multi- Start algorithm is adopted to solve the resulting constrained maximization problem. Finally, the validity of the proposed method is demonstrated with a Duffing oscillator and numerical case studies for problems with uncertainties are performed on a nonlinear two-degree of… More >