Alberto M. Coronado¹, Hanchen Huang²

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.1, pp. 39-44, 2005, DOI:10.3970/cmes.2005.010.039

Abstract Nanostructure fabrication or surface processing in general is predominantly kinetics-limited. One of the kinetics factors is surface diffusion, which involves intricate interplay between the diffusing atoms and substrate atoms. On Cu{111} surfaces, both adatoms and dimers diffuse very fast. Recent studies have shown that adatoms encounter a large facet-facet barrier, even though their conventional Ehrlich-Schwoebel barriers are small. This work examines the facet-facet diffusion barriers of dimers. Our results show that a dimer prefers diffusion through atom-by-atom mechanism, having a barrier of 0.52 eV from {111} to {111} facet and a barrier of 0.55 eV More >

C.-W. Chang¹, C.-S. Liu², J.-R. Chang^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.1, pp. 13-38, 2005, DOI:10.3970/cmes.2005.010.013

Abstract In this paper, the inverse heat conduction problem governed by sideways heat equation is investigated numerically. The problem is ill-posed because the solution, if it exists, does not depend continuously on the data. To begin with, this ill-posed problem is analyzed by considering the stability of the semi-discretization numerical schemes. Then the resulting ordinary differential equations at the discretized times are numerically integrated towards the spatial direction by the group preserving scheme, and the stable range of the index r = 1/2ν Δt is investigated. When the numerical results are compared with exact solutions, it More >

Z. D. Han¹, A. M. Rajendran², S.N. Atluri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.1, pp. 1-12, 2005, DOI:10.3970/cmes.2005.010.001

Abstract A nonlinear formulation of the Meshless Local Petrov-Galerkin (MLPG) finite-volume mixed method is developed for the large deformation analysis of static and dynamic problems. In the present MLPG large deformation formulation, the velocity gradients are interpolated independently, to avoid the time consuming differentiations of the shape functions at all integration points. The nodal values of velocity gradients are expressed in terms of the independently interpolated nodal values of displacements (or velocities), by enforcing the compatibility conditions directly at the nodal points. For validating the present large deformation MLPG formulation, two example problems are considered: 1)… More >

J. Bahen¹, O. Gaber¹, K. Behdinan², J. De Beer³, P. Zalzal⁴, M. Papini¹, M. Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 343-352, 2005, DOI:10.3970/fdmp.2005.001.343

Abstract The penetration of the reamer into the medullary cavity can be compared to a piston entering a cylinder filled with viscous fluid. When the flutes of the reamer are clogged with bone debris, fat and marrow, the piston effect is magnified and larger pressures are usually obtained. This paper considers a reamer with clogged flutes and investigates whether the rotation speed of the reamer has a significant influence on the pressure within the intramedullary cavity. The effect of reamer rotation speed on the pressure distribution within the bone is investigated numerically by solving the full More >

M.H. Djavareshkian¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 329-342, 2005, DOI:10.3970/fdmp.2005.001.329

Abstract A pressure-based Euler scheme, based on a collocated grid arrangement is described. The newly developed algorithm has two new prominent features: (i) the use of normalized variables to bound the convective fluxes and (ii) the use of a high-resolution scheme in calculating interface density values to enhance the shock-capturing property of the algorithm. The algorithm is first tested for flows at different Mach numbers ranging from subsonic to supersonic on a bump in a channel geometry; then the results are compared with the corresponding ones obtained without the bounded scheme in the correction step. The More >

M. Mosaad², A. Ben-Nakhi², M. H. Al-Hajeri²

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 301-314, 2005, DOI:10.3970/fdmp.2005.001.301

Abstract This work deals with the problem of thermal interaction between two fluid media at two different bulk temperatures and separated by a vertical plate. The problem is analyzed by taking into account the heat conduction across the separating plate. The flow configuration considered is one in which the two vertical boundary layers of free and forced convection developed on plate sides are in parallel flow. The dimensionless parameters governing the thermal interaction mechanisms are analytically deduced. The obtained results are presented in graphs to demonstrate the heat transfer characteristics of investigated phenomenon. The work reports More >

A. Ludwig^1,2, M. Gruber-Pretzler², M. Wu², A. Kuhn³, J. Riedle³

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 285-300, 2005, DOI:10.3970/fdmp.2005.001.285

Abstract This article has no abstract. More >

M.K. Achour¹, S. Kaddeche², A. Gharbi², H. Ben Hadid³, D. Henry³

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 277-284, 2005, DOI:10.3970/fdmp.2005.001.277

Abstract The effects of an acoustic wave on the instabilities occurring in a lateral differentially heated cavity are investigated numerically. Linear stability results show that the acoustic wave affects significantly the instability characteristics of such a Hadley flow. Indeed, the sound field is found to stabilize both two dimensional transverse stationary and three dimensional longitudinal oscillatory instabilities which are the most critical modes affecting the buoyant convection in the fluid layer. Nevertheless, when stabilized by an acoustic wave, the 2D modes turn from stationary to oscillatory, with the known consequences of such a change on mass More >

K. Sefiane¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.3, pp. 267-276, 2005, DOI:10.3970/fdmp.2005.001.267

Abstract In this paper the experimental results on the wetting behaviour of volatile binary sessile drops are reported. The evaporation rate is varied through the control of the ambient total pressure. The dynamic wetting contact angle of an evaporating Water-Ethanol drop is investigated at various sub-atmospheric pressures. The wetting properties (contact angle, shape and volume) are monitored in time using a drop shape analysis instrument. The results show that the evaporation of the binary droplet takes place in two stages: the first stage where the wetting behaviour is very similar to the pure ethanol case and… More >

C. Giessler¹, C. Sievert², U. Krieger¹, B. Halbedel¹, D. Huelsenberg¹, U. Luedke², A. Thess^1,2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.3, pp. 247-266, 2005, DOI:10.3970/fdmp.2005.001.247

Abstract Buoyancy driven motion of a highly viscous electrically conducting fluid under the influence of Lorentz forces is investigated theoretically and experimentally. This problem is relevant to the processing of glass, where it is of considerable interest to know whether electromagnetic forces can effectively improve mixing and help to avoid undesired flow patterns in glass melting furnaces. Two highly simplified models are proposed in which the fluid is assumed to be confined in a circular loop containing several localized resistive heating, convective cooling, and electromagnetic forcing elements. The first model is used to derive the scaling… More >