Ashraf Balabel

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.6, pp. 599-638, 2012, DOI:10.3970/cmes.2012.083.599

Abstract In the present paper, a new generalized level set numerical method based on the Fast Marching Method is developed for predicting the moving interface thermo-fluid dynamics in turbulent free surface flows. The numerical method is devoted to predict the turbulent interfacial dynamics resulting from either aerodynamic force or thermocapillary effects. The unsteady Reynolds averaged Navier-Stokes equations (RANS) and energy equation are coupled with the level set method and solved separately in each phase using the finite volume method on a non-staggered grid system. The application of the fast marching technique enables the fast as well… More >

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 More >

S.R. Santos¹, L.C. Matioli², A.T. Beck³

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.1, pp. 23-56, 2012, DOI:10.3970/cmes.2012.083.023

Abstract Solution of structural reliability problems by the First Order method require optimization algorithms to find the smallest distance between a limit state function and the origin of standard Gaussian space. The Hassofer-Lind-Rackwitz-Fiessler (HLRF) algorithm, developed specifically for this purpose, has been shown to be efficient but not robust, as it fails to converge for a significant number of problems. On the other hand, recent developments in general (augmented Lagrangian) optimization techniques have not been tested in aplication to structural reliability problems. In the present article, three new optimization algorithms for structural reliability analysis are presented.… More >

A. Khourchafi¹, M. El Alami^2,3, M. Najam², M. Belhaq⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.3, pp. 323-338, 2012, DOI:10.3970/fdmp.2012.008.323

Abstract A spectral radiation study has been carried out in the framework of a statistical narrow-band model based on an inverse-tailed exponential law and the socalled P1 approximation. This new spectral formulation, which may be also regarded as a grey band formulation with a local absorption coefficient, leads to two implementation methods: a non correlated form in which the averaged formulation of the P1 approximation does not take into account the correlation between fundamental quantities and a pseudo-correlated variant consisting basically of a technique for improving the anisotropy of the radiative intensity. Real gases (H₂O, CO₂) are More >

Arnaldo Mendez, Mohamad Sawan

Canadian Journal of Urology, Vol.18, No.1, pp. 5504-5516, 2011

Abstract Chronic monitoring of bladder volume can improve the clinical diagnosis and the choice of therapeutic approach for patients suffering from urinary dysfunction. It can also be employed to notify patients or healthcare personnel when the bladder should be emptied. An early warning can be triggered either when functional bladder capacity is reached or when an abnormally high postvoiding residual volume remains in the bladder after an unfinished voiding. Currently, neuroprosthetic implants are used in the treatment of refractory patients with overactive bladder, with urgency-frequency or with voiding complications. These implants can further enhance their performance, More >

P. Huke, Ralf B. Bergmann

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.3, pp. 69-70, 2011, DOI:10.3970/icces.2011.020.069

Abstract Non-destructive testing (NdT) describes a wide range of principles and methods for measuring and comparing physical quantities against a nominal condition. Commonly NdT is related the detection of defects in or on solid-state bodies. This may include hidden defects as well as optical appearance (reflectivity, absorbance, polarity), shape, stress, strain and many other characteristics. In many applications contactless NdT is advantageous due to the state of the object in question. Most often optical metrology, like shearography, reflectometry, vibrometry and laser ultrasound, is contactless or needs no physical contact to the measurement area. The optical NdT… More >

Xide Li

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.1, pp. 13-14, 2011, DOI:10.3970/icces.2011.020.013

Abstract The quantitatively assessment of defect characteristic parameters (DCP), such as coordinates, size, embedding depth and type of defects in structures or materials, is becoming increasingly important. One reason is for economy and safety, and the other for a defect in structures may lead to failure while it is growing to a critical size. Therefore, it is possible to estimate both remaining life of structures and extent of the degradation by knowing the dimensions of defects presenting in structures. In this paper, several research topics on quantitative detection of the DCP in our group are reviewed… More >

Lei Jiang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.2, pp. 47-48, 2011, DOI:10.3970/icces.2011.019.047

Abstract Ocean resources, for which the modern military and economy are competing, are the material sources for sustainable development. In order to keep our own rights in the competition of international resources, the project to develop a deep-sea HOV was started.
In this paper different requirements of O2 concentration in the closed space of various underwater vehicles such as submarine and HOV is introduced. Based on that, from the aspects of power, space size, influence to the environment and O2 concentration the particular demands for delivering O2 are analyzed. Several O2 delivering methods in the closed More >

Cheng-Yu Ku^1,2,3,Weichung Yeih^1,2, Chein-Shan Liu⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.76, No.2, pp. 83-108, 2011, DOI:10.3970/cmes.2011.076.083

Abstract In this paper, a general dynamical method based on the construction of a scalar homotopy function to transform a vector function of Non-Linear Algebraic Equations (NAEs) into a time-dependent scalar function by introducing a fictitious time-like variable is proposed. With the introduction of a transformation matrix, the proposed general dynamical method can be transformed into several dynamical Newton-like methods including the Dynamical Newton Method (DNM), the Dynamical Jacobian-Inverse Free Method (DJIFM), and the Manifold-Based Exponentially Convergent Algorithm (MBECA). From the general dynamical method, we can also derive the conventional Newton method using a certain fictitious… More >

Francesca Cosmi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.74, No.3&4, pp. 269-282, 2011, DOI:10.3970/cmes.2011.074.269

Abstract In industrial applications, microstructure inhomogeneities can derive from the manufacturing process and the final mechanical properties of the material depend on the resulting, complex, structural pattern of the constituents. In this paper, Cell Method plane models in the elastic and plastic fields are presented and applied to predict the behaviour of four sintered alloys, where the spatial arrangement of voids within the base material contributes to determine the mechanical behaviour. Unlike the Finite Elements and other methods, the Cell Method is a numerical method based on a direct discrete formulation of equilibrium equations, so that More >