L. Bennamoun¹, A. Belhamri², A. Ali Mohamed

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 177-192, 2009, DOI:10.3970/fdmp.2009.005.177

Abstract This study focuses on the interplay between drying kinetics (encountered in typical industrial processes and particularly in the context of solar drying) and the possible variation of external (e.g., environmental) conditions. Theoretical models of these behaviours are introduced. Experimental results confirmed by simulation are also presented. Variation of the thermo physical properties of air is taken into account in terms of variation of viscosity, density and coefficient of diffusion. In particular, this coefficient is calculated from experimental data and expressed as a function of the wet bulb air temperature. When external conditions are modified and,… More >

M.R. Arab^1,2, E. Semma³, B. Pateyron¹, M. El Ganaoui¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 161-176, 2009, DOI:10.3970/fdmp.2009.005.161

Abstract In this work, flows in porous media are simulated by using a Lattice Boltzmann Method (LBM). A model D2Q9 with a single collision operator is proposed. This method is applied on 2D digital images obtained by a Scanning Electron Microscope technique (SEM), and followed by a special treatment in order to obtain an image of synthesis that is finally read by the numerical code. The first results tested on two-dimensional configurations show the reliability of this strategy in simulating with a good accuracy phenomena of heat and mass transport. The numerical study is extended to More >

Norihan M. Arifin¹, Ioan Pop²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 149-160, 2009, DOI:10.3970/fdmp.2009.005.149

Abstract A linear stability analysis is used to investigate the onset of Marangoni convection in a three-layer system comprising an incompressible fluid saturated porous layer over which lies a layer of the same fluid and below which lies a solid layer. The lower boundary is subjected to a fixed heat flux, while the upper free surface of the fluid is non-deformable. At the interface between the fluid and the porous layer, the Beavers-Joseph slip condition is used and the Darcy law is employed to describe the flow in the porous medium. The asymptotic analysis of the More >

Aouachria Z¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 137-148, 2009, DOI:10.3970/fdmp.2009.005.137

Abstract This work treats heat and mass transfer by natural convection along a vertical wall in porous media imbibed by fluid, using an integral method. The problem governing parameters are the buoyancy ratio,N, and the Lewis number, Le The results for the local Nusselt and Sherwood numbers are presented for a large range of these parameters. The concentration and thermal boundary layer thickness are also determined. We observe that our results are in good agreement with those obtained by Bejan and Khair (1985). More >

Munther Issa K,ah¹, Jean-Luc Meunier²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 123-136, 2009, DOI:10.3970/fdmp.2009.005.123

Abstract Multi walled carbon nanotubes (MWCNTs) were synthesized on different graphite types covered with thin layer of nickel catalyst by catalytic chemical vapour deposition using acetylene as hydrocarbon source. The produced carbon nanotubes were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The shape, quantity and diameter of the MWCNTs are shown to be affected by the type of the graphite substrate, the growth temperature and the hydrocarbon source flow rate. The diameters of the produced MWCNTs were ranged between 43 and 80 nm for pyrolytic (PYROID) and polycrystalline More >

K.V. Pagalthivarthi¹, P.K. Gupta²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 93-122, 2009, DOI:10.3970/fdmp.2009.005.093

Abstract The objective of the present work is to predict erosive wear in multisize dense slurry flow in a rotating channel. The methodology comprises numerical prediction of two-phase flow which is accomplished using the Galerkin finite element method. The wear models for both sliding wear and impact wear mechanisms account for the particle size dependence. The effect of various operating parameters such as rotation rate, solids concentration, flow rate, particle size distribution and so forth has been studied. Results indicate that wear rate in general increases along the pressure-side of the channel with rotation rate, overall More >

Davood Kalantari¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 81-92, 2009, DOI:10.3970/fdmp.2009.005.081

Abstract In this paper a theoretical approach is elaborated for modelling the impact and ensuing spreading behaviour of a liquid droplet after its collision with a flat and rigid surface. The major outcomes of such a study can be summarized as follows: 1) The propagating-shock-wave velocity associated with the droplet is not a constant value but depends on the impact velocity and the physical and geometrical properties of the droplet. 2) The initial radial ejection velocity of the lamella is proportional to the shock-wave velocity (ua) and the impact velocity (0) according to the expression (a-u0)1/2. More >

Lassig, J.¹, Montes, G., Quiroga, J.

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 61-80, 2009, DOI:10.3970/fdmp.2009.005.061

Abstract This paper presents a description of the design and ensuing development of an automated liquid droplet generator and related utilization aboard the space shuttle, a) as a fluid positioning system for materials processing (attached droplet method), and b) as a means to measure surface oscillation of droplets under microgravity for determining their surface tension. More >

Edoardo Bucchignani¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 37-60, 2009, DOI:10.3970/fdmp.2009.005.037

Abstract This article describes an implicit method for the solution of time dependent Navier-Stokes equations written in terms of vorticity and velocity. The field equations are discretized using a finite volume technique over quadrilateral meshes.
The numerical code has been applied to the classical window cavity test, employing a fine stretched non-uniform grid, in order to provide an accurate steady solution for a high value of the Rayleigh number (10⁸). It has also been performed a simulation for a value of Rayleigh larger than the critical value, in order to show the capabilities of the proposed More >

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 >