Paras Ram^1,2, Vikas Kumar³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 179-196, 2014, DOI:10.3970/fdmp.2014.010.179

Abstract The present study is carried out to examine the effects of temperature dependent variable viscosity on the three dimensional steady axi-symmetric Ferrohydrodynamic (FHD) boundary layer flow of an incompressible electrically nonconducting magnetic fluid in the presence of a rotating disk. The disk is subjected to an externally applied magnetic field and is maintained at a uniform temperature. The nonlinear coupled partial differential equations governing the boundary layer flow are non dimensionalized using similarity transformations and are reduced to a system of coupled ordinary differential equations. To study the effects of temperature dependent viscosity on velocity profiles and temperature distribution within… More >

J.R. Lin¹, L.M. Chu², T.L. Chou³, L.J. Liang³, P.Y. Wang³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 163-177, 2014, DOI:10.3970/fdmp.2014.010.163

Abstract We investigate the influence of non-Newtonian micropolar fluids on the dynamic characteristics of wide tapered-land slider bearings. The study is carried out on the basis of the micro-continuum theory originally developed by Eringen (1966). Analytical expressions for the linear dynamic coefficients are provided and compared with earlier results in the literature. In particular, direct comparison with the Newtonian fluid-lubricated tapered-land bearings by Lin et al. (2006) indicates that the use of non-Newtonian micropolar fluids can lead to a significant increase in the values of stiffness and damping coefficients. Such improvements are found to be even more pronounced for larger values… More >

Y.Q. He, Q.C. Bi¹, D.X. Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.4, pp. 357-370, 2011, DOI:10.3970/fdmp.2011.007.357

Abstract The behavior of a single air bubble rising in magnetic fluids without magnetic fields is visualized using a mini-gap between two parallel vertical glass plates. Water-based Fe3O4 magnetic fluids with particle volume concentration of 6.33 % and density 1261.96 kgm - 3 are filled in these gaps and a single air bubble is produced through the orifice at the bottom of the gap. The thicknesses of the gaps are 1 and 2 mm, respectively. Diameters of the orifices are 0.64 and 1.02 mm for 1 mm gap, and 0.64, 1.02 and 1.6 mm for 2 mm gap. In addition, four… More >

Carole Planchette¹, Elise Lorenceau¹, Günter Brenn²

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.3, pp. 279-302, 2011, DOI:10.3970/fdmp.2011.007.279

Abstract This work is dedicated to a general description of collisions between two drops of immiscible liquids. Our approach is mainly experimental and allows us to describe the outcomes of such collisions according to a set of relevant parameters. Varying the relative velocity U as well as the impact parameter X we can build for each pair of investigated liquids a nomogram X,U showing three possible regimes: coalescence, head-on separation and off-center separation. In this paper, we also study the influence of the liquid properties, i.e. viscosity, density, surface and interfacial tensions using a set of aqueous glycerol solutions together with… More >

Robert Rundqvist¹, Andreas Mark¹, Fredrik Edelvik¹, Johan S. Carlsson¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.3, pp. 259-278, 2011, DOI:10.3970/fdmp.2011.007.259

Abstract Multiphase flow simulation using Smoothed Particle Hydrodynamics (SPH) has gained interest during recent years, mostly due to the inherent flexibility of the method and the physically rather intuitive formulation of extra constitutive equations needed when dealing with for instance non-Newtonian flows. In the work presented here, simulations based on an SPH model implemented in the flow solver IBOFlow has been used for simulation of robotic application of sealing material on a car body. Application of sealing materials is done in order to prevent water leakage into cavities of the body, and to reduce noise. In off-line programming of the robots… More >

S. Homma¹, M. Yokotsuka¹, T. Tanaka¹, K. Moriguchi¹, J. Koga¹, G. Tryggvason²

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.3, pp. 231-240, 2011, DOI:10.3970/fdmp.2011.007.231

Abstract We develop a three-fluid front-tracking method in order to simulate the motion of an axisymmetry compound droplet, which consists of three immiscible fluids separated by two different interfaces. The two interfaces of the compound droplet are represented by two different sets of the front-tracking elements immersed on the Eulerian grid mesh, where the velocities and the pressure are calculated. The density and viscosity profiles with jumps at the interfaces are successfully determined from the location and the connection information of the front-tracking elements. The motion of a compound droplet is simulated on axisymmetric cylindrical coordinates. The results show that the… More >

Massimo Corcione¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.2, pp. 175-200, 2011, DOI:10.3970/fdmp.2011.007.175

Abstract Free convection heat transfer in nanofluids from horizontal isothermal cylinders is investigated theoretically. The main idea upon which the present work is based is that nanofluids behave more like a single-phase fluid rather than like a conventional solid-liquid mixture. This assumption implies that all the convective heat transfer correlations available in the literature for single-phase flows can be extended to nanoparticle suspensions, provided that the thermophysical properties appearing in them are the nanofluid effective properties calculated at the reference temperature. In this connection, two empirical equations, based on a wide variety of experimental data reported in the literature, are proposed… More >

R.C. Bataller¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.3, pp. 337-350, 2010, DOI:10.3970/fdmp.2010.006.337

Abstract The present research gathers an accurate numerical study of the laminar flow induced in an incompressible upper-convected Maxwell (UCM) fluid by a linear stretching of a flat, horizontal and porous sheet in the presence of a transverse magnetic field. The governing partial differential equations are converted into an ordinary differential equation by a similarity transformation. The effects on the velocity field over the sheet of the parameters like elasticity number, suction/blowing velocity, and magnetic parameter are also studied. It has also been attempted to show capabilities and wide-range applications of the 4thorder Runge-Kutta method in comparison with the homotopy analysis… More >

Shaligram Tiwari¹, Koichi Nishino²

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.1, pp. 109-136, 2010, DOI:10.3970/fdmp.2010.006.109

Abstract The present work reports about an experimental study investigating the influence of air convection and of ambient temperature around a half-floating zone on the transition behavior from steady to oscillatory flow, i.e. the influence on the critical Marangoni number (Macr). Increase of heat loss from the free surface of the half-floating zone or liquid bridge by increased convection and ambient cooling decreases Macr. Heat input to the free surface increases Macr. An add-on numerical simulation of the air convection around the zone clarifies the influence of air convection and the ambient temperature on the temperature, surface velocity and local Biot… More >

O.M.Lavrenteva, Yu. Holenbergand A.Nir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.1, pp. 41-74, 2010, DOI:10.3970/fdmp.2010.006.041

Abstract A variety of exact analytical solutions describing natural and thermocapillary convection in a horizontal double layer system consisting of Newtonian and Herschel-Bulkley fluids subjected to longitudinal temperature and concentration gradients is constructed. The lower boundary of the system is a solid wall with no-slip, while the upper ones if either a solid wall or a free surface. It was demonstrated that, depending on the governing parameters of the system, viscoplastic layer is entirely yielded or unyielded, or it can be yielded partially, exhibiting up to 5 flowing and quasi-solid layers. The dependence of the flow patterns (appearance and position of… More >