H. Imtiaz¹, F. M. Mahfouz²

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.3, pp. 171-192, 2015, DOI:10.3970/cmes.2015.108.171

Abstract This paper investigates numerically the conjugate heat transfer in a concentric enclosure that is formed between two concentric cylinders and filled with micropolar fluid. The wall of inner cylinder is considerably thick, while the wall of outer cylinder is very thin. The inner cylinder is heated from inner side through constant heat flux, whereas the outer cylinder is cooled and maintained at constant temperature. The induced buoyancy driven flow and associated conjugate heat transfer are predicted numerically by solving flow and energy governing equations considering a combination of finite difference and Fourier spectral methods. The… More >

Foad Nazari¹, Mohammad Hossein Abolbashari^1,2, Seyed Mahmoud Hosseini³

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.4, pp. 271-299, 2015, DOI:10.3970/cmes.2015.105.271

Abstract Present study is concerned with three dimensional natural frequency analysis of functionally graded sandwich rectangular plates using Meshless Local Petrov-Galerkin (MLPG) method and Artificial Neural Networks (ANNs).The plate consists of two homogeneous face sheets and a power-law FGM core. Natural frequencies of the plate are obtained by 3D MLPG method and are verified with available references. Convergence study of the first four natural frequencies for different node numbers is the next step. Also, effects of two parameters of “FG core to plate thickness ratio” and “volume fraction index” on natural frequencies of plate are investigated. More >

S. Saha Ray¹

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.3, pp. 231-249, 2015, DOI:10.3970/cmes.2015.105.231

Abstract In the present article, a relatively very new technique viz. Coupled Fractional Reduced Differential Transform, has been executed to attain the approximate numerical solution of the predator-prey dynamical system. The fractional derivatives are defined in the Caputo sense. Utilizing the present method we can solve many linear and nonlinear coupled fractional differential equations. The results thus obtained are compared with those of other available methods. Numerical solutions are presented graphically to show the simplicity and authenticity of the method. More >

C.T. Lee¹, C.C. Lee²

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.5, pp. 375-403, 2015, DOI:10.3970/cmes.2015.104.375

Abstract In this article, we demonstrate a numerical 3-D chip, and studied the capillary dynamics inside the microchannel. We applied the level set method on the Navier-Stokes equation which incorporates the surface tension and two-phase flow characteristics. We analyzed the capillary dynamics near the junction of two microchannels. Such a highlighting point is important that it not only can provide the information of interface behavior when fluids are made into a head-on collision, but also emphasize the idea for the design of the chip. In addition, we study the pressure distribution of the fluids at the More >

Chekifi. T^1,2, Dennai. B¹, Khelfaoui. R¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 205-220, 2015, DOI:10.3970/fdmp.2015.011.205

Abstract Droplet generation, splitting and sorting are investigated numerically in the framework of a VOF technique for interface tracking and a finite-volume numerical method using the commercial code FLUENT. Droplets of water-in-oil are produced by a flow focusing technique relying on the use of a microchannell equipped with an obstacle to split the droplets. The influence of several parameters potentially affecting this process is investigated parametrically towards the end of identifying "optimal" conditions for droplet breakup. Such parameters include surface tension, the capillary number and the main channel width. We show that the capillary number plays More >

Imen Mejri^1,2, Ahmed Mahmoudi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 171-195, 2015, DOI:10.3970/fdmp.2015.011.171

Abstract This paper examines natural convection in an open cavity with a sinusoidal thermal boundary condition. The cavity is filled with a water-Al₂O₃ nanofluid and subjected to a magnetic field. The Lattice Boltzmann method (LBM) is applied to solve the coupled equations of flow and temperature. The study has been carried out considering parameters in the following ranges: Rayleigh number of the base fluid, Ra = 10³ to 10⁶, Hartmann number varied from Ha = 0 to 60, phase deviation γ = 0, π4, π2, 3 π4 and π and solid volume fraction of nanoparticles between π = More >

Bouchmel Mliki, Mohamed Ammar Abbassi, Ahmed Omri

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 87-114, 2015, DOI:10.3970/fdmp.2015.011.087

Abstract MHD double-diffusive natural convective flow in a C-shaped enclosure filled with a Cu/Water nanofluid is investigated numerically using the Lattice Boltzmann Method (LBM). Much care is devoted to the validation of the numerical code. The effects exerted on the flow, concentration and temperature fields by different parameters such as the Rayleigh number (10³−10⁶), the nanoparticle volume concentration (0−0,1), the Lewis number (1-5), the Hartmann number (0−30) and different types of nanoparticles (Cu, Ag, Al₂O₃ and TiO₃ are assessed in detail. Results for stream function, Nusselt and Sherwood numbers are presented and discussed for various parametric conditions. Results More >

Q.W. Yang¹, S.G. Du^1,2

CMC-Computers, Materials & Continua, Vol.47, No.3, pp. 217-236, 2015, DOI:10.3970/cmc.2015.047.217

Abstract Size effect is a major issue in concrete structures and occurs in concrete in any loading conditions. In this study, size effect on concrete cubic compressive strength is modeled with a back-propagation neural network. The main advantage in using an artificial neural network (ANN) technique is that the network is built directly from experimental data without any simplifying assumptions via the self-organizing capabilities of the neural network. The proposed ANN model is verified by using 27 experimental data sets collected from the literature. For the large specimens, a modified ANN is developed in the paper More >

Ang Li¹, Guo-jian Shao^1,2, Pei-rong Du³, Sheng-yong Ding¹, Jing-bo Su⁴

CMC-Computers, Materials & Continua, Vol.45, No.1, pp. 17-38, 2015, DOI:10.3970/cmc.2015.045.017

Abstract This paper investigates the failure behaviors of stratified rocks under uniaxial compression using a digital image processing (DIP) based finite difference method (FDM). The two-dimensional (2D) mesostructure of stratified rocks, represented as the internal spatial distribution of two main rock materials (marble and greenschist), is first identified with the DIP technique. And then the binaryzation image information is used to generate the finite difference grid. Finally, the failure behaviors of stratified rock samples are simulated by FDM considering the inhomogeneity of rock materials. In the DIP, an image segmentation algorithm based on seeded region growing… More >

Rodrigo Donalisio da Silva, Mary Beth Schulte, Roberto Miano, Diedra Gustafson, Leticia Nogueira, Fernando J. Kim

Canadian Journal of Urology, Vol.21, No.2, pp. 7185-7187, 2014

Abstract The prestigious Jackson Hole Seminars (JHS) successfully gathered several world leaders in academic urology and urologists in private practice for a unique scientific experience in Wyoming, USA. Unfortunately, this year Dr. Ralph Hopkins’ seat was empty but his spirit continue to be the driving force for the meeting’s excellence and friendship. The JHS has pioneered the concept of a Critique Panel comprised of previous speakers that would discuss in depth the presentations of the faculty chosen by the scientific board of the JHS. The 2014 JHS featured Dr. Fernando J. Kim, the President of JHS, More >