Ahmed Meskini, Mostafa Najam, Mustapha El Alami

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 97-110, 2011, DOI:10.3970/fdmp.2011.007.097

Abstract A numerical mixed convection investigation was carried out to study the enhancement of heat transfer in a square cavity with identical heated rectangular blocks adjacent to its upper wall, and submitted to a vertical jet of fresh air from below. The configuration so defined is an inverted "T"-shaped cavity presenting symmetry with respect to a vertical axis passing by the middle of the openings. The governing equations have been solved using the finite difference method. The parameters of this study are: Rayleigh number 10⁴ ≤ Ra ≤ 10⁶, Reynolds number 1 ≤ Re ≤ 1000, the opening More >

Mohamed Ammar Abbassi^1,2, Kamel Halouani¹, Xavier Chesneau³, Belkacem Zeghmati³

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 71-96, 2011, DOI:10.3970/fdmp.2011.007.071

Abstract Mixed convection inside a square cavity with inlet and outlet ports is numerically simulated considering thermal radiation effect. The non dimensional transfer equations, based on Boussinesq assumption and the radiative heat transfer equation are solved by the finite-volume-method and the TDMA algorithm. Results, presented for a gray fluid and a wide range of dimensionless numbers; Reynolds (Re=10-1000), Richardson (Ri=0-0.01), Boltzmann (Bo=0.1-100), radiation to conduction parameter (Rc=0.1-100), and optical thickness (τ = 0.1-10) show that the radiation significantly affects temperature distribution. Streamlines are also sensitive to radiative parameters (as optical thickness) but less than temperature. More >

Hicham Rouijaa¹, Mustapha El Alami², El Alami Semma³, Mostafa Najam²

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 57-70, 2011, DOI:10.3970/fdmp.2011.007.057

Abstract This article presents a numerical study on natural convection in a bidimensional inclined "T"-shaped cavity. The governing equations are solved in the framework of a control-volume method resorting to the SIMPLEC algorithm (for the treatment of pressure-velocity coupling). Special emphasis is given to the investigation of the effect of inclination on the heat transfer and mass flow rate. Results are discussed for Prandtl number Pr=0.72, geometry with: opening width C=0.15, blocks gap D=0.5, blocks height, B=0.5 and different values of the Rayleigh number (10⁴ ≤ Ra ≤ 10⁶). More >

A. Kidess¹, N. Armour¹, S. Dost^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 29-56, 2011, DOI:10.3970/fdmp.2011.007.029

Abstract When a metallic liquid is subject to strong magnetic body forces, the issues of convergence and numerical stability may arise in numerical simulations. Handling of magnetic body force terms needs care. In this work we have studied two open codes and discussed the related issues. Magnetic force and mass transport terms were added to these codes. Handling the stability issues was discussed. The developed systems were validated by two benchmark cases. Then, the dissolution process of silicon into the germanium melt was selected as an application. The objective was the numerical study of the dissolution More >

V. Shevtsova¹, A. Mialdun¹, H. Kawamura², I. Ueno², K. Nishino³, M. Lappa⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 1-28, 2011, DOI:10.3970/fdmp.2011.007.001

Abstract The experimental results from nine benchmark test cases conducted by five different groups are presented. The goal of this study is to build an experimental database for validation of numerical models in liquid bridge geometry. The need arises as comparison of numerical results with a single experiment can lead to a large discrepancy due to specific experimental conditions. Perfectly conducting rigid walls and, especially, idealized boundary conditions at the free surface employed in numerical studies are not always realized in experiments. The experimental benchmark has emphasized strong sensitivity of the threshold of instability to the More >

C. Wang¹, W. Gao¹, C.W. Yang¹, C.M. Song¹

CMC-Computers, Materials & Continua, Vol.25, No.1, pp. 19-46, 2011, DOI:10.3970/cmc.2011.025.019

Abstract The random interval response and probabilistic interval reliability of structures with a mixture of random and interval properties are studied in this paper. Structural stiffness matrix is a random interval matrix if some structural parameters and loads are modeled as random variables and the others are considered as interval variables. The perturbation-based stochastic finite element method and random interval moment method are employed to develop the expressions for the mean value and standard deviation of random interval structural displacement and stress responses. The lower bound and upper bound of the mean value and standard deviation More >

A Rama Chandra Murthy¹, Smitha Gopinath^1,2, Ashish Shrivastav¹, G. S. Palani¹, Nagesh R. Iyer¹

CMC-Computers, Materials & Continua, Vol.25, No.1, pp. 1-18, 2011, DOI:10.3970/cmc.2011.025.001

Abstract This paper presents methodologies for crack growth study and fatigue remaining life prediction of reinforced concrete structural components accounting for the corrosion effects. Stress intensity factor (SIF) has been computed by using the principle of superposition. At each incremental crack length, net SIF has been computed as the difference of SIF of plain concrete and reinforcement. The behaviour of reinforcement has been considered as elasto-plastic. Uniform corrosion rate has been assumed in the modeling. Corrosion effect has been accounted in the form of reduction in the diameter and modulus of elasticity of steel. Numerical studies More >

Surkay D. Akbarov^1,2, Arzu Turan³

CMC-Computers, Materials & Continua, Vol.24, No.3, pp. 257-270, 2011, DOI:10.3970/cmc.2011.024.257

Abstract The influence of the initial finite stretching or compressing of the strip containing a single crack on the Energy Release Rate (ERR) and on the SIF of mode I at the crack tips is studied by the use of the Three-Dimensional Linearized Theory of Elasticity. It is assumed that the edges of the crack are parallel to the face planes of the strip and the ends of the strip are simply supported. The initial finite strain state arises by the uniformly distributed normal forces acting at the ends of the strip. The additional normal forces More >

Cheng-Te Chi¹, Ming-Hsiao Lee², Wen-Hwa Chen^1,3

CMC-Computers, Materials & Continua, Vol.24, No.3, pp. 239-256, 2011, DOI:10.3970/cmc.2011.024.239

Abstract A novel three-dimensional adaptive element-free Galerkin method (EFGM) based on a uniform background grid is proposed to cope with the problems with extremely large deformation. On the basis of this uniform background grid, an interior adaptive strategy through an error estimation within the analysis domain is developed. By this interior adaptive scheme, additional adaptive nodes are inserted in those regions where the solution accuracy needs to be improved. As opposed to the fixed uniform background grid, these inserted nodes can move along with deformation to describe the particular local deformation of the structure. In addition,… More >

Chih-Wen Chang¹

CMC-Computers, Materials & Continua, Vol.24, No.3, pp. 209-238, 2011, DOI:10.3970/cmc.2011.024.209

Abstract In this study, we employ a semi-analytical scheme to resolve the three-dimensional backward heat conduction problem (BHCP) by utilizing a quasi-bound -ary concept. First, the Fourier series expansion method is used to estimate the temperature field u(x, y, z, t) at any time t < T. Second, we ponder a direct regularization by adding an extra term a(x, y, z, 0) to transform a second-kind Fredholm integral equation for u(x, y, z, 0). The termwise separable property of the kernel function allows us to acquire a closed-form regularized solution. In addition, a tactic to determine More >