M. M. Shemirani¹, M. Z. Saghir²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 11-21, 2013, DOI:10.3970/fdmp.2013.009.011

Abstract Producing homogeneous single bulk crystals requires a good understanding of the thermo-solutal behavior in the solvent region. This study explores simulation of the growth of large diameter single bulk crystals of silicon and germanium alloy from its melt utilizing Bridgman method. Both thermal and solutal diffusion of silicon and germanium in the molten SiGe alloy are of interest. It was observed that the diffusion dominates the transport phenomenon in the solvent region especially in the first 25 mm of the model due to having a Pe_T <<1. It was also found that the control of both More >

A. Balbay¹, H. Ülker², Ö. Şahin³

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 1-10, 2013, DOI:10.3970/fdmp.2013.009.001

Abstract In this study, drying behaviours of the outer shell peeled Bittim (Pistacia terebinthus) with initial moisture content of 42.2% (dry basis (d.b)) was investigated in a novel fixed bed drying system. The drying experiments were performed at different temperatures (40 °C, 60 °C and 80 °C), air velocities (0.5 m/s and 1 m/s) and weights (30 g and 40 g). A constant rate period was not observed in the drying of bittims; all the drying process occurred in falling rate period. Three models in literature were selected to fit the experimental data. The fit quality of models More >

R. Savino¹, V. Carandente¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 453-476, 2012, DOI:10.3970/fdmp.2012.008.453

Abstract A new small recoverable re-entry capsule with deployable heat shield is analyzed. The possible utilization of the capsule is for safe Earth return of science payloads or data from low Earth orbit at an inexpensive cost, taking advantage of its deployable structure to perform an aerobraking re-entry mission, with relatively low heat and mechanical loads. The system concept for the heat shield is based on umbrella-like frameworks and existing ceramic fabrics. An aerothermodynamic analysis is developed to show that the peak heat flux, for a capsule with a ballistic coefficient lower than 10 kg/m², is in More >

Paras Ram¹, Anupam Bhandari²

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 437-452, 2012, DOI:10.3970/fdmp.2012.008.437

Abstract The present problem is formulated by considering the dynamics of a ferromagnetic fluid of variable viscosity permeating a porous medium in a rotating system in the presence of a stationary boundary. The fluid at large distance from such a boundary (disk) is assumed to rotate at a given uniform angular velocity. The viscosity of the fluid is assumed to depend on the intensity of the applied magnetic field. The governing nonlinear partial differential equations are transformed into a set of coupled nonlinear ordinary differential equations resorting to a similarity transformation. The resulting system of equations More >

N. Labed¹, L. Bennamoun², J.P. Fohr³

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 423-436, 2012, DOI:10.3970/fdmp.2012.008.423

Abstract Intrinsic and relative permeability are indispensable parameters for performing transfers in porous media. In this paper, the conception and ensuing exploitation of a new testing ground for measuring the relative permeability of water and nitrogen are presented. The experimental work was elaborated in the Laboratory of Thermal Studies in Poitiers, (France) where brick samples were used to verify the performance of the proposed testing strategy. The results prove the existence of several stages during the drainage and the imbibitions. In particular, the three stages observed for the case of gas permeability reduce to only two More >

A.H. Ahadi¹, M.Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 397-422, 2012, DOI:10.3970/fdmp.2012.008.397

Abstract The numerical simulations of a thermodiffusion experiment in atmospheric pressure binary mixtures of water and isopropanol subject to micro-vibrations at reduced gravity are presented. The vibrations are induced on board ISS and FOTON-M3 due to many different reasons like crew activity, spacecraft docking or operating other experiments, etc. The effects of micro-gravity vibration were investigated in detail on all of the mixture properties. The influences of different cavity sizes as well as different signs of Soret coefficients in the solvent were considered. In this paper, the thermodiffusion experiment was subjected to two different g-jitter vibrations… More >

Walid Hassen¹, Mohamed Naceur Borjini², Habib Ben Aissia¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 381-396, 2012, DOI:10.3970/fdmp.2012.008.381

Abstract In this work we consider the problem related to the electro-thermo-convection of a dielectric fluid in a rectangular enclosure placed between two electrodes. This layer is subjected simultaneously to the injection of electric charges and to a thermal gradient. The influence of the electric Rayleigh number (200 - 1000) on the structure of the flow, the density of electric charge and heat transfer is investigated. An oscillatory flow is observed and discussed in detail. More >

Morteza Eslamian^1,2, M. Ziad Saghir^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 353-380, 2012, DOI:10.3970/fdmp.2012.008.353

Abstract In this paper recent advances pertinent to the applications of thermodiffusion or thermomigration in the fabrication of micro and nano metal-doped semiconductor-based patterns and devices are reviewed and discussed. In thermomigration, a spot, line, or layer of a p-type dopant, such as aluminum, which is deposited on a semiconductor surface, penetrates into the semiconductor body due to the presence of a temperature gradient applied across the wafer body. The trails of p-doped regions within an n-type semiconductor, in the form of columns or walls, may be used for several applications, such as the isolation of More >

F.Z. Ferahta^1,2, S. Bougoul¹, M. Médale², C. Abid²

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.3, pp. 339-352, 2012, DOI:10.3970/fdmp.2012.008.339

Abstract A numerical study is carried out to evaluate the thermal performances of a solar collector. As it is well known, that the thermal losses of such systems are mainly of a convective nature, the study is concentrated in particular on the features of natural convection that is activated in the air domain delimited by the upper glass and the lower absorber of the solar collector. The efficiency of such a system depends essentially on both the temperature difference and the distance between the absorber and the glass. Since the temperature difference remains an uncontrolled variable More >

A. Khourchafi¹, M. El Alami^2,3, M. Najam², M. Belhaq⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.3, pp. 323-338, 2012, DOI:10.3970/fdmp.2012.008.323

Abstract A spectral radiation study has been carried out in the framework of a statistical narrow-band model based on an inverse-tailed exponential law and the socalled P1 approximation. This new spectral formulation, which may be also regarded as a grey band formulation with a local absorption coefficient, leads to two implementation methods: a non correlated form in which the averaged formulation of the P1 approximation does not take into account the correlation between fundamental quantities and a pseudo-correlated variant consisting basically of a technique for improving the anisotropy of the radiative intensity. Real gases (H₂O, CO₂) are More >