Shih-Kai Chien¹, Tzu-Hsiang Yen¹, Yue-Tzu Yang¹, Chao-Kuang Chen^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.29, No.3, pp. 163-174, 2008, DOI:10.3970/cmes.2008.029.163

Abstract Conventional proton exchange membrane fuel cells (PEMFCs) have a straight gas flow serpentine channel, and hence the reactant gases are transferred to the catalyst layers as a result of diffusion alone. Since the diffusion process is inherently slow, the electrical performance of such PEMFCs is inevitably limited. In an attempt to improve the PEMFC performance, this study replaces the straight channel with containing different type of obstacles and conducts a series of lattice Boltzmann method simulations to investigate the flow field phenomena induced in a viscous liquid as it flows along the serpentine channel at Reynolds numbers ranging from Re=5~25.… More >

C. Moulinec¹, R. Issa², J.-C. Marongiu³, D. Violeau⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.25, No.3, pp. 133-148, 2008, DOI:10.3970/cmes.2008.025.133

Abstract The gridless Smoothed Particle Hydrodynamics (SPH) numerical method is preferably used in Computational Fluid Dynamics (CFD) to simulate complex flows with one or several convoluted free surfaces. This type of flows requires distorted meshes with classical Eulerian mesh-based methods or very fine meshes with Volume of Fluid method. Few 3-D SPH simulations have been carried out to our knowlegde so far, mainly due to prohibitive computational investment since the number of particles required in 3-D is usually too large to be handled by a single processor. In this paper, a parallel 3-D SPH code is presented. Parallelisation validation is discussed… More >

Cha’o-Kuang Chen¹, Shing-Cheng Chang¹, Szu-Yu Sun¹

CMES-Computer Modeling in Engineering & Sciences, Vol.22, No.3, pp. 203-216, 2007, DOI:10.3970/cmes.2007.022.203

Abstract In this study, the channel flow is discussed by the LBM simulations. In the cases of channel with obstacles inside, the square pillars play the role of causing interruption within the fluid field, and hence change the direction of fluid flow. The recirculation region is formed behind the obstacles and influences the fluid passed through not only in the velocity field but also in the temperature field. Therefore, heat transfer is enhanced in local region.
The field synergy principle is applied in the research to demonstrate that the increased interruption within the fluid increases the synergistic level between the… More >

S. Chen^1,2, Y. Liu^1,3, B.C. Khoo⁴, X.J. Fan⁵, J.T. Fan⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.3, pp. 181-196, 2007, DOI:10.3970/cmes.2007.019.181

Abstract The mesoscopic simulation for fluids flow in a square microchannel is investigated using dissipative particle dynamics. The velocity distribution for single fluid in a square channel is compared with the solutions of CFD solver, which is found to be in good agreement with each other. The no-slip boundary condition could be well held for the repulsive coefficient ranged from 9.68 to 18.0. For the same range of repulsive coefficient, various wettabilities could be obtained by changing the repulsive coefficient for binary immiscible fluids, in which the immiscible fluids are achieved by increasing the repulsive force between species. The typical motion… More >

P.M.J. Trevelyan¹, L. Elliott¹, D.B. Ingham¹

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.3, pp. 117-122, 2000, DOI:10.3970/cmes.2000.001.419

Abstract The potential flow in a semi-infinite channel with multiple semi-infinite oblique sub-channels is determined using the Schwarz-Christoffel transformation and complex potential theory. The standard iterative technique, i.e. the Newton-Raphson method with the Jacobian matrix approximated by a finite-difference quotient matrix, was employed with an alternative integration region to that found elsewhere in the literature is employed after integrating across the boundaries to determine the Schwarz-Christoffel transformation parameters which solely depend on the dimensions of the region being considered. Each semi-infinte channel permits integration at infinity perpendicularly across the channel and sub-channels, yielding some analytical relationships between these parameters. The remainder… More >

S. Slama¹, H. Kahalerras¹, B. Fersadou¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.3, pp. 155-172, 2017, DOI:10.3970/fdmp.2017.013.155

Abstract A numerical study is conducted to investigate the problem of mixed convection of a nanofluid in a vertical porous channel with one wall heated and the other cooled. The Darcy-Brinkman-Forchheimer model is used to describe the flow in the porous medium, considered as anisotropic in thermal conductivity, and the two-phase approach is adopted to simulate the motion of the nanofluid. The governing equations with the associated boundary conditions are solved by the finite volume method. The parametric study is focused on the variation of the Richardson number Ri, the heat fluxes ratio R_q, the Darcy number and the thermal conductivity… More >

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 cross section of the… More >

Brahim DENNAI^1*, Mohammed EL Bizani BELBOUKHARI¹ , Tawfiq CHEKIFI¹, Rachid KHELFAOUl¹

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.3, pp. 102-110, 2016, DOI:10.3970/fdmp.2016.012.102

Abstract Microfluidic systems are used and exploited in various fields, as they are highly specific and developed in their use. The micro devices are used in various analyzes of medical disciplines, chemical and other fields. Our research team "MAAt" within ENERGARID laboratory is in the process of triggered several lines of research in this area, the micro-mixing, separation of micro particles, droplet production. For that, we need tools and micro devices to study the phenomena.. In this work, we present a theoretical study and numerical simulation of micro device (micro diode Tesla). A Diode Tesla is similar to a heart valve… More >

Meryem NAOUM¹, Mustapha EL ALAMI²

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.2, pp. 56-68, 2016, DOI:10.3970/fdmp.2016.012.056

Abstract A numerical study of mixed convection from a U-shaped channel is carried out. The flow is considered two dimensionnel. The inlet opening is adjusted in the right vertical part of the channel, while the outlet one is placed on the left vertical part. Navier–Stokes equations are solved using a control volume method and the SIMPLEC algorithm is considered for the treatment of pressure–velocity coupling. Special emphasis is given to detail the effect of the Reynolds and Rayleigh numbers on the heat transfer generated by mixed convection. The results are given for the parameters of control as, Rayleigh number (5.10³≤Ra≤10⁷), Prandtl… More >

Chekifi. T^1,2, Dennai. B¹, Khelfaoui. R¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 205-220, 2015, DOI:10.3970/fdmp.2015.011.205

Abstract Droplet generation, splitting and sorting are investigated numerically in the framework of a VOF technique for interface tracking and a finite-volume numerical method using the commercial code FLUENT. Droplets of water-in-oil are produced by a flow focusing technique relying on the use of a microchannell equipped with an obstacle to split the droplets. The influence of several parameters potentially affecting this process is investigated parametrically towards the end of identifying "optimal" conditions for droplet breakup. Such parameters include surface tension, the capillary number and the main channel width. We show that the capillary number plays a crucial role in determining… More >