Open Access
ARTICLE
K. Han1, Y. T. Feng1, D. R. J. Owen1
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.1, pp. 1-30, 2010, DOI:10.3970/cmes.2010.059.001
Abstract A computational framework is established for effective modelling of fluid-thermal-particle interactions. The numerical procedures comprise the Discrete Element Method for simulating particle dynamics; the Lattice Boltzmann Method for modelling the mass and velocity field of the fluid flow; and the Discrete Thermal Element Method and the Thermal Lattice Boltzmann Method for solving the temperature field. The coupling of the three fields is realised through hydrodynamic interaction force terms. Selected numerical examples are provided to illustrate the applicability of the proposed approach. More >
Open Access
ARTICLE
G.C. Bourantas1, E.D. Skouras2,3, V.C. Loukopoulos4, G.C. Nikiforidis1
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.1, pp. 31-64, 2010, DOI:10.3970/cmes.2010.059.031
Abstract A meshfree point collocation method has been developed for the velocity-vorticity formulation of two-dimensional, steady state incompressible Navier-Stokes equations. Particular emphasis was placed on the application of the velocity-correc -tion method, ensuring the continuity equation. The Moving Least Squares (MLS) approximation is employed for the construction of the shape functions, in conjunction with the general framework of the point collocation method. Computations are obtained for regular and irregular nodal distributions, stressing the positivity conditions that make the matrix of the system stable and convergent. The accuracy and the stability of the proposed scheme are demonstrated through two representative, well-known, and… More >
Open Access
ARTICLE
Caibin Zeng1, Qigui Yang1
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.1, pp. 65-78, 2010, DOI:10.3970/cmes.2010.059.065
Abstract In this paper, a fractional order model is established to describe HIV internal viral dynamics involving HAART effect. First, the model is proved to possess non-negative solutions as desired in any population dynamics. Then, a detailed analysis is carried out to study the stability of equilibrium points. Numerical simulations are presented to illustrate the stability analysis. More >
Open Access
ARTICLE
Peter Lucas1, Alexander H. van Zuijlen1, Hester Bijl1
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.1, pp. 79-106, 2010, DOI:10.3970/cmes.2010.059.079
Abstract Despite the advances in computer power and numerical algorithms over the last decades, solutions to unsteady flow problems remain computing time intensive.
In previous work [Lucas, P.,Bijl, H., and Zuijlen, A.H. van(2010)], we have shown that a Jacobian-free Newton-Krylov (JFNK) algorithm, preconditioned with an approximate factorization of the Jacobian which approximately matches the target residual operator, enables a speed up of a factor of 10 compared to nonlinear multigrid (NMG) for two-dimensional, large Reynolds number, unsteady flow computations. Furthermore, in [Lucas, P., Zuijlen, A.H. van, and Bijl, H. (2010)] we show that this algorithm also greatly outperforms NMG for parameter… More >