D. Ngo-Cong, N. Mai-Duy, W. Karunasena, T. Tran-Cong

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.5, pp. 459-498, 2012, DOI:10.3970/cmes.2012.083.459

Abstract The partition of unity method is employed to incorporate the moving least square (MLS) and one dimensional-integrated radial basis function (1D-IRBFN) techniques in a new approach, namely local MLS-1D-IRBFN or LMLS-1D-IRBFN. This approach leads to sparse system matrices and offers a high level of accuracy as in the case of 1D-IRBFN method. A new numerical procedure based on the 1D-IRBFN method and LMLS-1D-IRBFN approach is presented for a solution of fluid-structure interaction (FSI) problems. A combination of Chorin's method and pseudo-time subiterative technique is presented for a transient solution of 2-D incompressible viscous Navier-Stokes equations in terms of primitive variables.… More >

D. Ngo-Cong^1,2, N. Mai-Duy¹, W. Karunasena², T. Tran-Cong^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.3, pp. 311-352, 2012, DOI:10.3970/cmes.2012.083.311

Abstract In this study, local moving least square - one dimensional integrated radial basis function network (LMLS-1D-IRBFN) method is presented and demonstrated with the solution of time-dependent problems such as Burgers' equation, unsteady flow past a square cylinder in a horizontal channel and unsteady flow past a circular cylinder. The present method makes use of the partition of unity concept to combine the moving least square (MLS) and one-dimensional integrated radial basis function network (1D-IRBFN) techniques in a new approach. This approach offers the same order of accuracy as its global counterpart, the 1D-IRBFN method, while the system matrix is more… More >

D. Ngo-Cong^1,2, N. Mai-Duy¹, W. Karunasena², T. Tran-Cong^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.3, pp. 275-310, 2012, DOI:10.3970/cmes.2012.083.275

Abstract In this paper, natural convection flows in concentric and eccentric annuli are studied using a new numerical method, namely local moving least square - one dimensional integrated radial basis function networks (LMLS-1D-IRBFN). The partition of unity method is used to incorporate the moving least square (MLS) and one dimensional-integrated radial basis function (1D-IRBFN) techniques in an approach that leads to sparse system matrices and offers a high level of accuracy as in the case of 1D-IRBFN method. The present method possesses a Kronecker-Delta function property which helps impose the essential boundary condition in an exact manner. The method is first… More >

Zhen Luo^1,2, Nong Zhang^1,3, Yu Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.1, pp. 73-96, 2012, DOI:10.3970/cmes.2012.083.073

Abstract This paper aims to present a physically meaningful level set method for shape and topology optimization of structures. Compared to the conventional level set method which represents the design boundary as the zero level set, in this study the boundary is embedded into non-zero constant level sets of the level set function, to implicitly implement shape fidelity and topology changes in time via the propagation of the discrete level set function. A point-wise nodal density field, non-negative and value-bounded, is used to parameterize the level set function via the compactly supported radial basis functions (CSRBFs) at a uniformly defined set… More >

C.-D. Tran¹, D.-A. An-Vo¹, N. Mai-Duy¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.82, No.2, pp. 137-162, 2011, DOI:10.32604/cmes.2011.082.137

Abstract This paper presents a numerical approach for macro-micro multi-scale modelling of visco-elastic fluid flows based on the Integrated Radial Basis Function Networks (IRBFNs) and the Stochastic Simulation Technique (SST). The extra stress is calculated using the Brownian configuration fields (BCFs) technique while the velocity field is locally approximated at a set of collocation points using 1D-IRBFNs. In this approach, the stress is decoupled from the velocity field and computed from the molecular configuration directly without the need for a closed form rheological constitutive equation. The equations governing the macro flow field are discretised using a meshless collocation method where the… More >

N. Mai-Duy¹, T. Tran-Cong¹, N. Phan-Thien²

CMES-Computer Modeling in Engineering & Sciences, Vol.79, No.3&4, pp. 223-236, 2011, DOI:10.3970/cmes.2011.079.223

Abstract This paper presents a new numerical technique for solving the evolution equations in molecular dynamics (MD). The variation of the MD system is represented by radial-basis-function (RBF) equations which are constructed using integrated multiquadric basis functions and point collocation. The proposed technique requires the evaluation of forces once per time step. Several examples are given to demonstrate the attractiveness of the present implementation. More >

C. A. Bustamante¹, W. F. Florez¹, H. Power², M. Giraldo¹, A. F. Hill¹

CMES-Computer Modeling in Engineering & Sciences, Vol.79, No.2, pp. 103-130, 2011, DOI:10.3970/cmes.2011.079.103

Abstract The two-dimensional Navier Stokes system of equations for incompressible flows is solved in the velocity vorticity formulation by means of the Control Volume-Radial Basis Function (CV-RBF) method. This method is an improvement to the Control Volume Method (CVM) based on the use of Radial Basis Function (RBF) Hermite interpolation instead of the classical polynomial functions. The main advantages of the CV-RBF method are the approximation order, the meshless nature of the interpolation scheme and the presence of the PDE operator in the interpolation. Besides, the vorticity boundary values are computed in terms of the values of the velocity field at… More >

Htike Htike¹, Wen Chen¹, Yan Gu¹, Junjie Yang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.4, pp. 247-272, 2011, DOI:10.3970/cmes.2011.072.247

Abstract This paper makes the first attempt to employ the Radial Basis Function (RBF) interpolation in the material point method (MPM), in which the shape function is based on RBF and polynomial function and satisfies the partition of unity and possesses Delta-function property. It is worthy of stressing that the RBF interpolation has the merit of high smoothness and is very accurate and can easily be applied to the MPM framework for mapping information between moving particles, known as material point in the MPM, and background grids. The RBF-based MPM is designed to overcome the unphysical results, such as shear stress… More >

Annamaria Mazzia¹, Flavio Sartoretto²

CMES-Computer Modeling in Engineering & Sciences, Vol.68, No.1, pp. 95-112, 2010, DOI:10.3970/cmes.2010.068.095

Abstract Meshless methods for the solution of Partial Differential Equations receive nowadays increasing attention. Many meshless strategies have been proposed. The majority of meshless variational methods one can find in the literature, use Radial Basis Functions (RBF) as generators of suitable trial and test spaces. One of the main problems encountered when exploiting RBF is performing numerical integrations over circles (when 2D problems are attacked, spheres for 3D ones). We exploit Tensor Product Functions (TPF) as the test function space. This strategy allows one to consider rectangular integration domains, which are much easier to manage. This paper numerically analyzes the effectiveness… More >

K. Le-Cao¹, N. Mai-Duy¹, C.-D. Tran¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.67, No.3, pp. 265-294, 2010, DOI:10.3970/cmes.2010.067.265

Abstract In this paper, radial basis functions are utilised for numerical prediction of the bulk properties of particulate suspensions under simple shear conditions. The suspending fluid is Newtonian and the suspended particles are rigid. Results obtained are compared well with those based on finite elements in the literature. More >