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 >

Chengsheng Yuan^1,2,3, Xinting Li³, Q. M. Jonathan Wu³, Jin Li^4,5, Xingming Sun^1,2

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 357-372, 2017, DOI:10.3970/cmc.2017.053.357

Abstract Fingerprint-spoofing attack often occurs when imposters gain access illegally by using artificial fingerprints, which are made of common fingerprint materials, such as silicon, latex, etc. Thus, to protect our privacy, many fingerprint liveness detection methods are put forward to discriminate fake or true fingerprint. Current work on liveness detection for fingerprint images is focused on the construction of complex handcrafted features, but these methods normally destroy or lose spatial information between pixels. Different from existing methods, convolutional neural network (CNN) can generate high-level semantic representations by learning and concatenating low-level edge and shape features from… More >

Guo Zhao^1,2, Jiang Guo^1,2, Hao Qiang³

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 343-356, 2017, DOI:10.3970/cmc.2017.053.343

Abstract As a good measure to tackle the challenges from energy shortages and environmental pollution, Electric Vehicles (EVs) have entered a period of rapid growth. Battery swapping station is a very important way of energy supply to EVs, and it is urgently needed to explore a coordinated control strategy to effectively smooth the load fluctuation in order to adopt the large-scale EVs. Considering bidirectional power flow between the station and power grid, this paper proposed a SFLA-based control strategy to smooth the load profile. Finally, compared simulations were performed according to the related data. Compared to More >

S.D. Akbarov^1,2, M. Negin³

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 307-341, 2017, DOI:10.3970/cmc.2017.053.307

Abstract Dispersion of the generalized Rayleigh waves propagating in a covered half-space made of viscoelastic materials is investigated by utilizing the exact equations of the theory of linear viscoelasticity. The dispersion equation is obtained for an arbitrary type of hereditary operator of the materials of the constituents and a solution algorithm is developed for obtaining numerical results on the dispersion of the waves under consideration. Dispersion curves are presented for certain attenuation cases and the influence of the viscosity of the materials is studied through three rheological parameters of the viscoelastic materials which characterize the characteristic More >

Haolong Chen^1,2, Bo Yu¹, Huanlin Zhou^1*, Zeng Meng¹

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 271-290, 2017, DOI:10.3970/cmc.2017.053.271

Abstract The cuckoo search algorithm (CS) is improved by using the conjugate gradient method(CGM), and the CS-CGM is proposed. The unknown inner boundary shapes are generated randomly and evolved by Lévy flights and elimination mechanism in the CS and CS-CGM. The CS, CGM and CS-CGM are examined for the prediction of a pipe’s inner surface. The direct problem is two-dimensional transient heat conduction in functionally graded materials (FGMs). Firstly, the radial integration boundary element method (RIBEM) is applied to solve the direct problem. Then the three methods are compared to identify the pipe’s inner surfacewith the… More >

Arzu Turan Dincel¹, Surkay D. Akbarov^2,3

CMC-Computers, Materials & Continua, Vol.53, No.3, pp. 249-270, 2017, DOI:10.32604/cmc.2017.053.265

Abstract This paper deals with the mathematical modelling and 3D FEM study of the energy release rate (ERR) in the band crack’s front contained in the orthotropic thick rectangular plate which is stretched or compressed initially before the loading of the crack's edge planes. The initial stretching or compressing of the plate causes uniformly distributed normal stress to appear acting in the direction which is parallel to the plane on which the band crack is located. After the appearance of the initial stress in the plate it is assumed that the crack's edge planes are loaded… More >