M. El Alami¹, E. A. Semma^2,3, M. Najam¹, R. Boutarfa²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 23-36, 2009, DOI:10.3970/fdmp.2009.005.023

Abstract This study is devoted to the investigation of natural convection in a two dimensional horizontal channel with rectangular heated blocks at the bottom. The aspect ratio of the channel is A = L'/H' = 5. The blocks are heated with a constant temperature while the upper plane of the channel is cold. The governing equations are solved using a finite volumes method and the SIMPLEC algorithm is used for the treatment of the pressure-velocity coupling. Special emphasis is given to detail the effect of the Rayleigh number and blocks height on the heat transfer and the More >

W.F.Yuan¹, K.H.Tan ¹

CMC-Computers, Materials & Continua, Vol.13, No.1, pp. 49-62, 2009, DOI:10.3970/cmc.2009.013.049

Abstract A simple cellular automaton (CA) scheme is proposed to simulate heat conduction in anisotropic domains. The CA is built on random nodes rather than an irregular grid. The local rule used in the CA is defined by physical concepts instead of differential equations. The accuracy of the proposed approach is verified by classical examples. As an application of the proposed method, the CA approach is incorporated into fibre model which is widely used in finite element analysis to calculate the temperature distribution on the cross-section of composite beams. Numerical examples demonstrate that the proposed scheme More >

K Nagamani Devi¹, D.W. Pepper²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.1, pp. 13-18, 2008, DOI:10.3970/icces.2008.006.013

Abstract Over the past few years, efforts have been made to solve fluid flow and heat transfer problems using radial basis functions. This approach is meshless, easy to understand, and simple to implement. Preliminary results indicate accuracies on the order of finely meshed conventional techniques, but with considerably less computational effort. In this study, a projection-based technique is used to solve the primitive equations of motion and energy using radial basis functions. Three benchmark test cases are examined: (1\hbox {}) lid-driven cavity flow, (2\hbox {}) natural convection in a square enclosure, and (3\hbox {}) flow with More >

E. Y. K. Ng¹, S. T. Tan²

CMES-Computer Modeling in Engineering & Sciences, Vol.23, No.1, pp. 13-28, 2008, DOI:10.3970/cmes.2008.023.013

Abstract Microchannels have been recognized as a very effective chemical separation and heat transfer device. The electrical double layer (EDL) effect in a micro-scale flow is however anticipated to be critical. In this paper, Nernst-Planck model (NPM), is used to predict the ion concentration distribution as it is reported to be a more appropriate model for developing microchannel flow. The governing equations are discretised for developing rectangular microchannel flows in Cartesians coordinate. An additional body force source term that is relating to the electric potential, resulted from the EDL effect is introduced in the conventional z-axis momentum More >

R. Henda¹, W. Quesnel², Z. Saghir³

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.4, pp. 237-244, 2008, DOI:10.3970/fdmp.2008.004.237

Abstract The transient thermal behavior of a two-dimensional circulating porous bed is analytically investigated. A one-energy equation model, representing both the gas and solid phases via a unified temperature, is employed to describe the thermal behavior of the circulating bed. The latter is essentially a tube and shell heat exchanger commonly used in technologically important applications. The model equation is transformed into a simpler set of partial differential equations using an analytical procedure. The analytical solution, based on the method of separation of variables and the principle of superposition, is formulated for the calculation of the More >

A.Z. Lorbiecka¹, R.Vertnik², H.Gjerkeš¹, G. Manojlovič², B.Senčič², J. Cesar², B.Šarler^1,3

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 195-208, 2008, DOI:10.3970/cmc.2008.008.195

Abstract A numerical model is developed for the simulation of solidification grain structure formation (equiaxed to columnar and columnar to equiaxed transitions) during the continuous casting process of steel billets. The cellular automata microstructure model is combined with the macroscopic heat transfer model. The cellular automata method is based on the Nastac's definition of neighborhood, Gaussian nucleation rule, and KGT growth model. The heat transfer model is solved by the meshless technique by using local collocation with radial basis functions. The microscopic model parameters have been adjusted with respect to the experimental data for steel 51CrMoV4. More >

Bohdan Mochnacki¹, Grażyna Kaluża²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.1, pp. 15-20, 2007, DOI:10.3970/icces.2007.001.015

Abstract This article has no abstract. More >

N. Osawa¹, K. Hashimoto¹, J. Sawamura¹, J. Kikuchi², Y. Deguchi², T. Yamaura²

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.1, pp. 43-54, 2007, DOI:10.3970/cmes.2007.020.043

Abstract A new hypothesis regarding heat transmission during line heating is proposed. It states that the distribution of the temperature of the gas adjacent to the plate, T_G, and the overall local heat transfer coefficient, α, depend only on the distance from the torch. An identification technique for T_G and α is developed. The validity of the employed hypothesis and the proposed technique is demonstrated by comparing the measured and identified T_G during a spot heating test. The plate temperature calculated by direct heat conduction analysis closely approximates the one measured for the spot and line heating tests, More >

V.G. Kozlov¹, N.V. Selin²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.2, pp. 107-118, 2006, DOI:10.3970/fdmp.2006.002.107

Abstract Thermal vibrational convection in a sector of a thin spherical liquid layer subjected to pendulum vibrations (spherical pendulum) is investigated theoretically and experimentally. Temperature non-uniformity inside the liquid is caused by uniformly distributed internal heat sources (one side of the layer is isothermal, the other one is adiabatic). Experiments are carried out under conditions of stable temperature stratification in the gravity field. Heat transfer and convective structure are investigated in a wide interval of governing dimensionless parameters. A critical increase of heat transfer is revealed as the vibrations intensity is increased, caused by average convection. More >

N. Simões^1,2, A. Tadeu²

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.3, pp. 221-234, 2005, DOI:10.3970/cmes.2005.009.221

Abstract The use of the Boundary Element Method (BEM) to formulate the 3D transient heat transfer through cylindrical structures with irregular cross-sections, bounded by a homogeneous elastic medium, is described in this paper. In this formulation, both the conduction and the convection phenomena are modeled. This system can be subjected to heat emitted by either point or line sources located somewhere in the media. The solution is first obtained in the frequency domain for a wide range of frequencies and axial wavenumbers. Time domain responses are later calculated by means of (fast) inverse Fourier transforms into More >