M. Ihdene¹, T. Ben Malek², S. Aberkane³, M. Mouderes⁴, P. Spiterri⁵, A. Ghezal²

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.2, pp. 85-105, 2017, DOI:10.3970/fdmp.2017.013.085

Abstract We consider an ascending laminar air flow in a vertical channel formed by two parallel flat plates wetted by a thin water film and under different temperature and concentration conditions. The study includes a numerical finite volume method for the treatment of the double diffusion problem, where the analytical solution is given to the thermal diffusion. The analytical study showed that the reversed flow is observed only under some wall temperature conditions and also for certain values of Re/Gr. The reversed flow is also strongly dependent on the aspect ratio A₂, which is based on the… More >

Mohamed Ammar Abbassi¹, Bouchmel Mliki¹, Ridha Djebali^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.2, pp. 59-83, 2017, DOI:10.3970/fdmp.2017.013.059

Abstract This article reports a numerical study of nanoparticle Brownian motion and magnetic field effects by natural convection in a nanofluid-filled open cavity with non uniform boundary condition. Lattice Boltzmann Method (LBM) is used to simulate nanofluid flow and heat transfer. The effective thermal conductivity and viscosity of nanofluid are calculated by KKL (Koo-Kleinstreuer-Li) correlation. In this model effect of Brownian motion on the effective thermal conductivity and effective viscosity is considered and examined. Simulations have been carried out for the pertinent parameters in the following ranges: Rayleigh number (Ra=10³−10⁶), Hartmann number (Ha=0-60), nanoparticle volume concentration (Φ=0–0.04) and More >

Kamil Sobczak^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.1, pp. 49-57, 2017, DOI:10.3970/fdmp.2017.013.049

Abstract The paper presents a simple although effective method of obtaining gold and silver nanoparticles of average size of less than 3 nm. The nanoparticles were obtained by the Bredig’s electric arc method. Then colloidal preparations were centrifuged with acceleration equals to 29000 xg. It has been showed that subjecting the colloid to the hour centrifugation process repeated four times allows to obtain nanoparticles whose size does not exceed 5 nm. The nanoparticles prepared using this method were characterized by a high purity that depended only on the water and the cleanliness of the noble metal More >

Mustapha FARAJI¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.1, pp. 19-36, 2017, DOI:10.3970/fdmp.2017.013.019

Abstract A two-dimensional numerical model that accounts for heat transfer by conduction and natural convection in the molten region of nano enhanced Phase Change Material (PCM) is performed. Numerical investigations were conducted using an enthalpy- porosity method in order to examine the impact of the dispersion of copper (CuO) nanoparticles on the heat source temperature and the effect on the heat sink secured working time and the melting rate. Results show that heat spreads more easily along the conducting plate and to the PCM and, consequently, the PCM melts rapidly and the heat source is efficiency More >

N. Soltani¹, S. Rahal¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.1, pp. 1-17, 2017, DOI:10.3970/fdmp.2017.013.001

Abstract A three-dimensional time-dependent numerical study of the flow instabilities in a simulated Czochralski system is conducted. The comparison with previously published experimental results is reported. The simulations were performed using a refined grid in order to investigate flow instabilities in the crucible. Simulations have been carried out for various crystal rotational speeds, by taking into account the effects of Rayleigh and Marangoni numbers. The temperature fluctuations near the crystal/liquid interface are analyzed. The method used for that purpose is the Fast Fourier Transform with the corresponding spectra. From numerical simulations, it has been observed that More >

S. Fashu^{1 *}, M.Tozvireva¹, L.Mudzingwa¹, R.Khan², A. Mukuya¹

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.4, pp. 173-192, 2016, DOI:10.3970/fdmp.2016.012.173

Abstract This paper outlines the findings in the comparison of the influence of mechanical and electromagnetic stirring on ingot long term purity and uniformity during Ohno Continuous Casting. The magnitude of the average optimum velocity flow field and stirring parameters required to effectively purify aluminum ingots using mechanical stirring of the melt was determined and analyzed. Basing on the determined optimum mechanical flow field, electromagnetic parameters producing almost the same flow field near the interface were obtained through careful adjustments of parameters. Optimum parameters of the mechanical and electromagnetic stirring were obtained by numerically solving the… More >

Anupam Bhandari¹

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.4, pp. 155-171, 2016, DOI:10.3970/fdmp.2016.012.155

Abstract The present problem addresses a thermally driven two-dimensional, buoyant flow in a vessel with the application of magnetic field directed in the radial and tangential direction. In the present study, a trough filled with ferrofluid is heated along the center strip by an applied heat flux. Thereby the convection pattern along with the heat distribution is observed. The half of the trough dynamics is calculated with the symmetric plane in the center. On the surface of the bowl, penalty function is applied to enforce the no-slip boundary condition. This problem is then modelled and the More >

Saber Hamimid¹, Messaoud Guellal²

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.4, pp. 137-153, 2016, DOI:10.32604/fdmp.2016.012.137

Abstract The numerical study of combined thermo-magnetic convection and surface radiation is presented in this paper and computations are performed for a paramagnetic fluid filled square cavity whose four walls have the same emissivity, placed in a micro-gravity environment (g ≈0), and subjected to various strong non-uniform magnetic field gradients. The vertical walls were isothermal, and the horizontal walls were adiabatic. Finite volume method based on the concepts of staggered grid and SIMPLER algorithm has been applied, and the view factors were determined by analytical formula. Representative results, illustrating the effect of magnetic field strength on More >

Hadil Abu Khalifeh¹, Hadi Belhaj²

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.3, pp. 124-135, 2016, DOI:10.3970/fdmp.2016.012.124

Abstract In this work, asphaltenes precipitation and deposition induced by applying an electric field to Abu Dhabi crude oil sample were studied. The asphaltic particle electrical charge and asphaltic deposits mass at different operating conditions were determined. Direct current (DC) was applied between two graphite electrodes dipped in crude oil/synthetic formation water mixture of 240K ppm salinity. Three current densities of 10, 20, and 30 A/m2 were applied. Deposits were collected on the electrodes surfaces and their mass was recorded using low capacity load cells (up to 50g). Anodic and cathodic deposits were observed at different… More >

Hameed Muhamad¹, Simant Upreti ², Ali Lohi³, Huu Doan⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.3, pp. 111-123, 2016, DOI:10.3970/fdmp.2016.012.111

Abstract Heavy Oil is an up and coming energy resource that is aggressively being sought after as the world’s energy demand increases. As technology continues to improve, this once costly energy source is quickly becoming a more viable alternative. Vapor extraction (Vapex) process is an emerging technology for viscous oil recovery that has gained much attention in the oil industry. The vapor extraction of heavy oil system is presented to describe experimental setups and procedures used to perform different experiments of vape extraction process. The generated experimental data were used to calculate the live oil maximum… More >