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 >

P. A. Dinesh¹, N. Nalinakshi², D. V. Ch,rashekhar³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 465-490, 2014, DOI:10.3970/fdmp.2014.010.465

Abstract Heat and Mass transfer from a vertical heated plate embedded in a sparsely packed porous medium with internal heat generation and variable fluid properties like permeability, porosity and thermal conductivity has been investigated numerically. In particular, the governing highly non-linear coupled partial differential equations are transformed into a system of ordinary differential equations with the help of similarity transformations and solved numerically by using a shooting algorithm based on a Runge-Kutta-Fehlberg scheme and a Newton Raphson method (to obtain velocity, temperature and concentration distributions). The heat and mass transfer characteristics are analyzed and related physical aspects are discussed in detail… More >

M. Kriraa^1,2, M.EL Alami¹, M. Abouricha¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 443-464, 2014, DOI:10.3970/fdmp.2014.010.443

Abstract Natural Convection in a vertical channel with internal objects is encountered in several technological applications, among them particular interest of heat dissipation from electronic circuits, refrigerators, heat exchangers, nuclear reactors fuel elements, dry cooling towers, home ventilation, etc. This numerical study deals with the study of natural convection in a vertical convergent channel with a circular block. The considered parameters are 10⁴ ≤ Ra ≤ 10⁶, Prandtl number Pr = 0.71, channel height 10 ≤ A ≤ 30, inclination angle of the channel φ = 0,2.86°,5.74°. The size block conductivity and the block radius are assumed to be constant Λ… More >

Gnaneswara Reddy Machireddy¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 417-442, 2014, DOI:10.3970/fdmp.2014.010.417

Abstract This study deals with the investigation of the effects exerted by heat radiation and a first-order chemical reaction on the magnetohydrodynamics boundary layer slip flow which is established past a vertical permeable surface embedded in a porous medium (with uniform heat and mass flux). The heat equation includes the relevant terms, i.e. the viscous dissipation, radiative heat flux, Ohmic dissipation, and absorption of radiation. The mass transfer equation takes into account the effects related to the chemically reactive species. A classical model for optically thin media is used for studying the effect of radiation. The resulting non-linear coupled partial differential… More >

M’barka Mourabit¹, Hicham Rouijaa¹, El Alami Semma¹, Mustapha El Alami², Mostafa Najam²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 395-415, 2014, DOI:10.3970/fdmp.2014.010.395

Abstract We study the effect of inclination angle on mixed convection in a "T" form cavity containing two openings and two heated blocks mounted on its lower wall. The blocks are maintained at a constant temperature T_H. The lower wall is adiabatic and submitted to a vertical air jet while the upper wall is kept cold at a constant temperature T_C < T_H. The vertical walls are rigid and adiabatic. The governing equations are solved by a finite volume method. Special attention is devoted to the solution symmetry, the flow structure and the heat exchange through the cavity. The considered control… More >

S. Hamimid^1,2, M. Guellal¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 377-393, 2014, DOI:10.3970/fdmp.2014.010.377

Abstract Combined laminar natural convection and surface radiation in a differentially heated square cavity has been investigated by a finite volume method through the concepts of staggered grid and SIMPLER approach. A power scheme has been also used in approximating advection–diffusion terms, determining the view factors by means of analytical expressions. The effect of emissivity on temperature and velocity profiles within the enclosure has been analyzed. In addition, results for local and average convective and radiative Nusselt numbers are presented and discussed for various conditions. 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 >

A. Abbassi^1,2, N. Kechiche¹, H. Ben Aissia¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 319-341, 2014, DOI:10.3970/fdmp.2014.010.319

Abstract Jet transition towards a turbulent state is an interesting topic requiring a detailed analysis of the process leading to the onset and amplification of small flow disturbances. Here we examine experimentally the transition process for an isothermal laminar round free jet at low values of the Reynolds number. Close to the inlet nozzle, the turbulence intensity is assumed to be small enough so that the initial shear layer can be considered laminar and the velocity profile uniform. Experimental data are obtained using a Laser Doppler Anemometry (LDA) technique at various longitudinal and transversal coordinates, (x,y). Spectral analysis of the instantaneous… More >

A. Behjatian¹, A. Esmaeeli¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 299-317, 2014, DOI:10.3970/fdmp.2014.010.299

Abstract Computational studies are performed to explore the underlying physics behind the evolution of the flow field in an around a liquid jet that is immersed in another liquid and is exposed to a uniform electric field. Here the focus is on finite Reynolds and O(1) Ohnesorge number flows. This is achieved by solving the full Navier-Stokes and electric field equations using a front tracking/finite difference technique in the framework of Taylor's leaky dielectric theory. It is shown that the evolution of the flow field is determined by the relative magnitude of the ratio of the electric conductivity R = σ_i/σ_o… More >