P. T. Hemamalini¹, S. P. Anjali Devi²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 491-501, 2014, DOI:10.3970/fdmp.2014.010.491

Abstract The Rayleigh-Taylor instability (RTI) of two superposed ferrofluids subjected to rotation and a periodic tangential magnetic field is considered. Relevant solutions and related dispersion relations are obtained by using the method of multiple scales. More >

Anupam Bh,ari¹, Vipin Kumar²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 359-375, 2014, DOI:10.3970/fdmp.2014.010.359

Abstract The purpose of this paper is to study the flow characteristics of a ferrofluid revolving through a porous medium with a magnetic-field-dependent viscosity in the presence of a stationary disk. A Finite Difference Method is employed to discretize the set of nonlinear coupled differential equations involved in the problem. The discretized nonlinear equations, in turn, are solved by a Newton method (using MATLAB) taking the initial guess with the help of a PDE Solver. Results displayed in graphical form are used to assess the effect of the variable viscosity and porosity parameters on the velocity components. The displacement thickness of… More >

D.V. Jayalakshmamma¹, Dinesh P.A.², M. Sankar³, D.V. Ch,rashekhar⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 343-357, 2014, DOI:10.3970/fdmp.2014.010.343

Abstract We examine the motion of the two concentric immiscible liquid spheres with different viscosities in an electrically conducting fluid in the presence of transverse magnetic field. The inner sphere is assumed to move at a constant velocity. The Stoke’s equation along with the Lorentz force is considered to model the resulting fluid flow, analytical solutions being obtained by the similarity solution method in terms of modified Bessel’s functions. Streamlines related to the fluid circulation in the annulus between the two liquid spheres and inside the inner liquid sphere are presented for different combinations of the governing non-dimensional parameters. More >

Paras Ram^1,2, Vikas Kumar³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 179-196, 2014, DOI:10.3970/fdmp.2014.010.179

Abstract The present study is carried out to examine the effects of temperature dependent variable viscosity on the three dimensional steady axi-symmetric Ferrohydrodynamic (FHD) boundary layer flow of an incompressible electrically nonconducting magnetic fluid in the presence of a rotating disk. The disk is subjected to an externally applied magnetic field and is maintained at a uniform temperature. The nonlinear coupled partial differential equations governing the boundary layer flow are non dimensionalized using similarity transformations and are reduced to a system of coupled ordinary differential equations. To study the effects of temperature dependent viscosity on velocity profiles and temperature distribution within… More >

Imen Mejri^1,2, Ahmed Mahmoudi¹, Mohamed Ammar Abbassi¹, Ahmed Omri¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 83-114, 2014, DOI:10.3970/fdmp.2014.010.083

Abstract This study examines natural convection in a square enclosure filled with a water-Al₂O₃ nanofluid and subjected to a magnetic field. The side walls of the cavity have spatially varying sinusoidal temperature distributions. The horizontal walls are adiabatic. A Lattice Boltzmann method (LBM) is applied to solve the governing equations for fluid velocity and temperature. The following parameters and related ranges are considered: Rayleigh number of the base fluid, from Ra=10³ to 10⁶, Hartmann number from Ha=0 to 90, phase deviation (γ =0, π/4, π/2, 3π/4 and π) and solid volume fraction of the nanoparticles between ø = 0 and 6%.… 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 process with and without the… More >

S. Hamimid¹, A.Amroune¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.4, pp. 369-384, 2010, DOI:10.3970/fdmp.2010.006.369

Abstract The Navier-Stokes and energy equations are numerically solved to investigate two-dimensional convection (originating from the combined effect of buoyancy and surface tension forces) in a liquid metal subjected to transverse magnetic fields. In particular, a laterally heated horizontal cavity with aspect ratio (height/width) =1 and Pr=0.015 is considered (typically associated with the horizontal Bridgman crystal growth process and commonly used for benchmarking purposes). The effect of a uniform magnetic field with different magnitudes and orientations on the stability of the two distinct convective solution branches (with a single-cell or two-cell pattern) of the steady-state flows is investigated. The effects induced… More >

S. Bouabdallah^1,2, R. Bessaïh¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.3, pp. 251-276, 2010, DOI:10.3970/fdmp.2010.006.251

Abstract In this paper, a numerical study of magnetohydrodynamics stability during phase change of a pure metal (liquid Gallium) in a cubical enclosure is presented. An external magnetic field is applied in X-, Y-, and Z-directions separately. Two electric potential boundary conditions are considered: electrically conducting and insulating walls. The finite-volume method with enthalpy formulation is used to solve the mathematical model in the solid and liquid phases. The Grashof number is fixed at Gr =105and the Hartmann number is varied from Ha= 0 to 200. The effect of magnetic field on the flow field and heat transfer, and on the… More >

N. Armour¹, S. Dost^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 331-344, 2009, DOI:10.3970/fdmp.2009.005.331

Abstract A combined numerical and experimental investigation has been undertaken to explore the benefits of an applied static magnetic field on Silicon transport into a Germanium melt. This work utilized a similar material configuration to that used in the Liquid Phase Diffusion (LPD) and Melt-Replenishment Czochralski (Cz) growth systems. The measured concentration profiles from the samples processed with and without the application of magnetic field showed very similar shape. The amount of silicon transport into the melt is slightly higher in the samples processed under magnetic field, and there is a substantial difference in dissolution interface shape indicating a change in… More >

F. Mechighel^1,2, M. El Ganaoui¹, M. Kadja², B. Pateyron³, S. Dost⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 313-330, 2009, DOI:10.3970/fdmp.2009.005.313

Abstract A numerical study has been carried out to investigate the three-dimen -sional buoyant flow in a parallelepiped box heated from below and partially from the two sidewalls (a configuration commonly used for solidification problems and crystal growth systems). Attention has been paid, in particular, to phenomena of symmetry breaking and transition to unsteady non-symmetric convection for a low Prandtl number fluid (Pr=0.01). The influence of an applied horizontal magnetic field on the stability properties of the flow has been also considered. Results obtained may be summarized as follows: In the absence of magnetic field and for relatively small values of… More >