Open Access
ARTICLE
Luca Bergamaschi1,2, ,Ángeles Martínez2, Giorgio Pini2
CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.3, pp. 191-216, 2009, DOI:10.3970/cmes.2009.049.191
Abstract A meshless model, based on the Meshless Local Petrov-Galerkin (MLPG) approach, is developed and implemented in parallel for the solution of axi-symmetric poroelastic problems. The parallel code is based on a concurrent construction of the stiffness matrix by the processors and on a parallel preconditioned iterative method of Krylov type for the solution of the resulting linear system. The performance of the code is investigated on a realistic application concerning the prediction of land subsidence above a deep compacting reservoir. The overall code is shown to obtain a very high parallel efficiency (larger than 78% for the solution phase) and… More >
Open Access
ARTICLE
Gerardo Anguiano-Orozco1,2, Rubén Avila3
CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.3, pp. 217-254, 2009, DOI:10.3970/cmes.2009.049.217
Abstract A numerical investigation of the transient, three dimensional, laminar natural convection of a fluid confined in a spherical container is carried out. Initially the fluid is quiescent with a uniform temperature Ti equal to the temperature of the wall of the container. At time t=0, the temperature of the wall is suddenly lowered to a uniform temperature Tw=0. The natural convection, that conducts to a vortex ring formation within the sphere, is driven by a terrestrial gravity force (laboratory gravity) and by the step change in the temperature of the wall. A scaling analysis of a simplified transient, two dimensional… More >
Open Access
ARTICLE
Haiping Ye1, Yongsheng Ding2
CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.3, pp. 255-268, 2009, DOI:10.3970/cmes.2009.049.255
Abstract A fractional-order model for the immunological and therapeutic control of HIV is studied qualitatively. The equilibria are found and their local stability are investigated. Also the global stability of the infection-free equilibrium is established. The optimal efficacy level of anti-retroviral therapy needed to eradicate HIV from the body of an HIV-infected individual is obtained. More >
Open Access
ARTICLE
S. Tangaramvong, F. Tin-Loi
CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.3, pp. 269-296, 2009, DOI:10.3970/cmes.2009.049.269
Abstract We consider the optimal synthesis, namely minimum weight design, of rigid perfectly-plastic structures for which some supports involve unilateral frictional contact. This problem is of interest as it is not only encountered in practice but it also involves, in the general friction case, a nonassociative complementarity condition that makes it theoretically and numerically challenging. For simplicity of exposition, we focus on the class of bar structures for which yielding is governed by either pure bending or by combined axial and flexural forces. In view of possible multiplicity of solutions due to nonassociativity, a direct optimization formulation may lead to an… More >