Yuan Chen¹, Honggang Duan¹, Fei Yu¹, Xingyu Zhao¹, Han Xu¹, Jun Gao^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 127-142, 2015, DOI:10.3970/fdmp.2015.011.127

Abstract The dynamics of dispersed bubbles in a centrifugal separator are investigated with the aim to improve the efficiency of the system. The prototype separator consists of a rotor, a base, a diverting disc, a shaft, an oil trapping impeller, a central pipe, an inlet section for contaminated oil, an outlet section for purified oil and an air outlet. A hydrodynamic model is developed to predict the complex influence of parameters such as the centrifugal force and vacuum pressure. In particular, three different force models are selected to analyze the effect of the added mass and More >

S. Aggoune¹, C. Abid², E.H. Amara^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 115-125, 2015, DOI:10.3970/fdmp.2015.011.115

Abstract This paper focuses on the vortex formation effect during the application of a laser-fusion cutting technique. This industrial technique is typically associated with the ejection of a film of molten stainless steel blown off by a subsonic laminar jet of nitrogen gas used to assist the process. Without taking into account the transverse movement of the workpiece, we consider a 4 mm thick stainless steel plate. The resulting molten metal flow is assumed to be laminar, steady, viscous and incompressible. The numerical results reveal vortex structures adjacent to the walls at the entrance of the More >

Bouchmel Mliki, Mohamed Ammar Abbassi, Ahmed Omri

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 87-114, 2015, DOI:10.3970/fdmp.2015.011.087

Abstract MHD double-diffusive natural convective flow in a C-shaped enclosure filled with a Cu/Water nanofluid is investigated numerically using the Lattice Boltzmann Method (LBM). Much care is devoted to the validation of the numerical code. The effects exerted on the flow, concentration and temperature fields by different parameters such as the Rayleigh number (10³−10⁶), the nanoparticle volume concentration (0−0,1), the Lewis number (1-5), the Hartmann number (0−30) and different types of nanoparticles (Cu, Ag, Al₂O₃ and TiO₃ are assessed in detail. Results for stream function, Nusselt and Sherwood numbers are presented and discussed for various parametric conditions. Results More >

Z. Bouhssine¹, M. Faraji¹, M. Najam¹, M. El Alami^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 63-85, 2015, DOI:10.3970/fdmp.2015.011.063

Abstract The objective of this study is to optimize the thermal performance of a solar collector. The solar collector is coupled to a building slab with a PCM layer. A mathematical model for the thermal behavior of the studied system is developed using the enthalpy method. The model parameters are defined and the resulting equations are solved iteratively. Several simulations were carried out to optimize the proposed heating system. The results show that the inlet temperature fluctuations are less pronounced than those at the outlet. More >

J.R. Lin¹, T.L. Chou², L.J. Liang², M.C. Lin², P.H. Lee²

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 49-61, 2015, DOI:10.3970/fdmp.2015.011.049

Abstract The characteristics of a hydromagnetic non-Newtonian squeeze film formed between parallel rectangular plates under the application on an external magnetic field are investigated. A specific hydromagnetic non-Newtonian Reynolds equation is derived via pplication of the hydromagnetic flow theory together with the micro-continuum theory. It is found that the coupled effects of electrically conducting fluids and micropolar fluids result in a higher load capacity and a longer approaching time with respect to the non-conducting Newtonian case. These improved characteristics become more pronounced as the magnetic Hartmann parameter, the coupling parameter, and the fluid-gap parameter are increased. More >

C. S. Iorio¹, C. Perfetti¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 27-48, 2015, DOI:10.3970/fdmp.2015.011.027

Abstract In the past few years, modeling of the Acoustic StandingWaves (ASW) phenomena has become a topic of great interest due to its theoretical connections with particle/cells manipulation techniques, which represent important tools in the biotechnology field. The present paper proposes a model based on the use of moving wall boundary conditions coupled with a viscous compressible fluid in a square channel. This model successfully achieved the generation of ASWs in the square cross-section for several resonance frequencies; the corresponding acoustic potential for the fundamental resonant mode and several harmonics have also been calculated and are More >

Kentaro Doi^1,2, Yuzuru Chikasako¹, Satoyuki Kawano^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 1-26, 2015, DOI:10.3970/fdmp.2015.011.001

Abstract Propylene carbonate (PC) and ethylene carbonate are known as good candidates of organic solvents to be used in Li-ion rechargeable batteries, since Li⁺ ions exhibit preferable charge-discharge characteristics with such solvents. On the other hand, polar solvents usually form solvation shells with solute ions, and cause a drastic reduction of ionic conductivity. Along these lines, there has been a curious question why the diffusion coefficient D_Li of Li⁺ strongly depends on the salt concentration. In the present study, a theoretical model is developed on the basis of the Langevin equation in which the interactions between ions and… More >

Hawa Singh¹, Paras Ram², Vikas Kumar³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 521-550, 2014, DOI:10.3970/fdmp.2014.010.521

Abstract The fluctuating flow produced by magneto - hydrodynamic free convection past an impulsively started isothermal vertical plate is studied taking into account the effects of radiation and viscous dissipation. By using the similarity transformation, the governing equations are transformed into dimensionless form and then the system of nonlinear partial differential equations is solved by a perturbation technique. The considered uniform magnetic field acts perpendicular to the plate, which absorbs the fluid with a given suction velocity. A comparison is made in velocity and temperature profiles for two particular cases of real and imaginary time dependent More >

F. Iachachene¹, A. Matoui², Y. Halouane¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 503-520, 2014, DOI:10.3970/fdmp.2014.010.503

Abstract Computations related to a heat transfer and fluid flow of a plane isothermal fully developed turbulent plane jet flowing into a rectangular hot cavity are reported in this paper. Both velocity and temperature distributions are computed by solving the two-dimensional Unsteady Reynolds Averaged Navier--Stokes (URANS) equations. This approach relies on one point statistical modeling based on the energy - specific dissipation (k-ω) turbulence model. The numerical simulations are carried out in the framework of a finite volume method. This problem is relevant to a wide range of practical applications including forced convection and the ventilation of More >

P. T. Hemamalini¹, S. P. Anjali Devi²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 491-501, 2014, DOI:10.3970/fdmp.2014.010.491

Abstract The Rayleigh-Taylor instability (RTI) of two superposed ferrofluids subjected to rotation and a periodic tangential magnetic field is considered. Relevant solutions and related dispersion relations are obtained by using the method of multiple scales. More >