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 heat generation or… 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 wire which have been used.… 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 cooled by the addition of… More >

ZichunYang¹, Gaohui Su^1,2, Bin Chen¹

CMC-Computers, Materials & Continua, Vol.51, No.1, pp. 43-62, 2016, DOI:10.3970/cmc.2016.051.043

Abstract The molecular dynamics (MD) simulations were used to understand the heat transfer process between the gas phase and the solid skeleton in the nanoporous silica aerogels. The amorphous silica nanoparticles were generated by the MD simulations and the energy accommodation coefficient (EAC) between the gases and the nanoparticles was calculated based on the results of the nonequilibrium molecular dynamics (NEMD) simulations. The apparent thermal conductivity (ATC) of the gases between the heat source and heat sink was also obtained. The effects of the temperature, the particle diameter and the molecule type on the EAC and the ATC were investigated. The… More >

Edward Van Keuren¹, MakiNishida¹

CMC-Computers, Materials & Continua, Vol.14, No.1, pp. 61-78, 2009, DOI:10.3970/cmc.2009.014.061

Abstract Room temperature solution-based synthetic methods are an important option for the production of a wide range of nanomaterials. These methods often rely on self-assembly or self-organization of molecular precursors, with specific control of their nucleation and growth properties. We are developing strategies for the creation of multifunctional composite nanoparticles as well as models for predicting the bulk properties from the individual components and parameters of the processing conditions. One method of synthesis is a reprecipitation technique in which nanoparticle nucleation and growth is induced by the rapid injection of a molecular solution into a miscible non-solvent. Here we demonstrate that… More >