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ARTICLE

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 for rotational speeds of the… More >

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ARTICLE

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 cooled by the addition of… More >

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Bin Liu¹, Zhaodan Yang¹, Yahui Wang¹, Rachid Bennacer^1,2
FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.1, pp. 37-47, 2017, DOI:10.3970/fdmp.2017.013.037
Abstract The dynamic thermal history of storage product system is related to the insulation and also to the inertia. Use a new porous media doped with nanofluid PCM to improve the system efficiency. The analysis of the porous sponge thickness with 8 mm, 16 mm and 20 mm, the integrated nanofluids with 0.1%, 0.15% and 0.2%, the mass of the PCM and the initial temperature of the stored product with -1°C, 4°C, 12°C is achieved in order to underline the advantages of the new saturated porous media (sponges) with the phase change material (PCM) /Al₂O₃-H₂O nanofluid. The carrots are used as… More >

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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 wire which have been used.… More >

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