M.R. Moosavi¹, A. Khelil¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.4, pp. 211-238, 2008, DOI:10.3970/icces.2008.005.211

Abstract In this paper, a combined formulation of the Finite Volume Method (FVM) and the Meshless Local Petrov-Galerkin (MLPG) is investigated to solve elasto-static problem. Accuracy and computational efficiency study between the combined formulation and the Finite Element Method (FEM) is presented. Some problems of beam under various loading and boundary conditions are analyzed by the proposed method, and the numerical results are compared with analytical solution and result of other numerical method which is obtained by well-known FEM software ABAQUS. The advantages of the FVM combined MLPG (FVMLPG) with respect to the FEM are illustrated. More >

T.Z. Desta¹, G. De Bruyne¹, J.-M. Aerts¹, M. Baelmans², D. Berckmans¹

CMES-Computer Modeling in Engineering & Sciences, Vol.31, No.2, pp. 61-70, 2008, DOI:10.3970/cmes.2008.031.061

Abstract This paper demonstrates the use of the concept of the local mean age of air (LMAA) to quantify ventilation effectiveness under bicycle rider's safety helmets. The specific objective is to study the effect of helmet openings on the resulting ventilation effectiveness. To quantify ventilation effectiveness using the concept of LMAA, dynamic tracer gas data are necessary. The data were generated using a Computational Fluid Dynamics (CFD) model. Two bicycle helmet designs were used and compared with respect to ventilation performance. The result showed that the helmet with more openings had better performance especially at the More >

F.C. Araújo¹, L.J. Gray²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.2, pp. 41-46, 2007, DOI:10.3970/icces.2007.002.041

Abstract This paper is concerned with the solution of boundary-element models based on substructuring. Structured matrix-vector products and the matrix-copy option are proposed to increase the efficiency of algorithms based on Krylov solvers. The former technique was designed to avoid the excessive number of conditional tests during solver iterations, and the latter one, to avoid the repeated calculation of coefficient matrices for identical subregions. Potential applications of the algorithm to composite materials, and to develop parallel codes, are noted. More >

J. M. F. Trindade¹, J. C. F. Pereira²

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.1, pp. 1-10, 2007, DOI:10.3970/cmes.2007.020.001

Abstract In this paper, we discuss the efficiency and speed-up of parallel-in-time calculations of the unsteady incompressible Navier-Stokes equations in a PC-cluster. The parallel-in-time method is based on the alternate use of coarse global sequential solvers with fine local parallel ones in an iterative predictor-corrector fashion. Therefore, the efficiency of parallel calculations is strongly dependent on the number of iterations required for convergence. The one-dimensional scalar transport equation and the two-dimensional incompressible unsteady form of the Navier-Stokes equations were used to conduct numerical experiments to derive some conclusions concerning the accuracy and convergence of the iterative… More >

Y.F. Nie¹, S. Chang¹, X.K. Fan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.2, pp. 135-144, 2007, DOI:10.3970/cmes.2007.019.135

Abstract A new parallel mechanism for Node-based Seamless Finite Element Method was proposed in this paper, which possessed the following three prominent points: realizing the workload balance for the parallel processes naturally, achieving synchronization of all the schedules under complex parallel environment, and filling up the gap between pre-processing and main processing. To support the scheme, three specific solutions of the parallel mechanism were proposed in this paper, all of which achieved the highly efficient parallel seamless connection between the FEM mesh generation process and structure analysis process. Two of the three schemes, i.e. dynamic scheme More >

Hernández-Castillo¹ FD, Adalberto Aguirre-Aguirre¹, RH Lira-Saldivar², E Guerrero-Rodríguez¹, G Gallegos-Morales¹

Phyton-International Journal of Experimental Botany, Vol.75, pp. 91-101, 2006, DOI:10.32604/phyton.2006.75.091

Abstract The biological efficiency of five stocks of Bacillus subtilis, of the mixture of the bioproducts quitosan and Larrea tridentata extract, and five synthetic fungicides were evaluated against the fungus Alternaria dauci Kühn in laboratory and greenhouse experiments. The effect of these compounds on growth and yield of carrot was also determined. Stocks of the bacteria Bacillus (B3, B9, B15 and a combination of these) and the mixture quitosan- Larrea stimulated carrot development because it reached greater width, length and weight in comparison to the control and the other treatments. Stock B3 was the best in promoting carrot growth More >