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. More >

M. Chrigui^1,2, L. Schneider¹, A. Zghal², A. Sadiki¹, J. Janicka¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.4, pp. 399-408, 2010, DOI:10.3970/fdmp.2010.006.399

Abstract This paper deals with the numerical simulation of droplet dispersion and evaporation within an LPP (Lean Premix Prevaporized) burner. The Eulerian-Lagrangian approach was used for this purpose, and a fully two way-coupling was accounted for. For the phase transition, a non-equilibrium evaporation model was applied that differs strongly from the equilibrium one where there are high evaporation rates. The non-equilibrium conditions were fulfilled in the investigated configuration, as the droplets at the inlet had a mean diameter of 50mm. The numerical results of water droplet velocities, corresponding fluctuations, and diameters were compared with experimental data. More >

Rodica Borcia¹, Michael Bestehorn²

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.1, pp. 1-12, 2010, DOI:10.3970/fdmp.2010.006.001

Abstract We study numerically the fully nonlinear evolution of thin liquid films on solid supports in three spatial dimensions. A phase field model is used as mathematical tool. Homogeneous and inhomogeneous substrates are taken into account. For flat homogeneous substrates the stability of thin liquid layers is investigated under the action of gravity. The coarsening process at the solid boundary can be controlled on inhomogeneous substrates. On substrates chemically patterned in an adequate way with hydrophobic and hydrophilic spots (functional surfaces), one can obtain stable regular liquid droplets as final dewetted morphology. More >

Davood Kalantari¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 81-92, 2009, DOI:10.3970/fdmp.2009.005.081

Abstract In this paper a theoretical approach is elaborated for modelling the impact and ensuing spreading behaviour of a liquid droplet after its collision with a flat and rigid surface. The major outcomes of such a study can be summarized as follows: 1) The propagating-shock-wave velocity associated with the droplet is not a constant value but depends on the impact velocity and the physical and geometrical properties of the droplet. 2) The initial radial ejection velocity of the lamella is proportional to the shock-wave velocity (ua) and the impact velocity (0) according to the expression (a-u0)1/2. More >

Lassig, J.¹, Montes, G., Quiroga, J.

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 61-80, 2009, DOI:10.3970/fdmp.2009.005.061

Abstract This paper presents a description of the design and ensuing development of an automated liquid droplet generator and related utilization aboard the space shuttle, a) as a fluid positioning system for materials processing (attached droplet method), and b) as a means to measure surface oscillation of droplets under microgravity for determining their surface tension. More >

Sayavur I. Bakhtiyarov¹, Dennis A. Siginer²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 1-22, 2009, DOI:10.3970/fdmp.2009.005.001

Abstract Strong inhomogeneous magnetic fields are necessary to generate a finite levitation force in ground based electromagnetic levitation techniques. External forces such as magnetic and gravitational forces influence the oscillation spectrum and counteract the surface movement resulting in a frequency shift, and making the use of electromagnetic levitation techniques in microgravity an attractive alternative to measure thermophysical properties of liquid metals. Under microgravity conditions the magnetic field strength around a liquid droplet is significantly lower than that required to position the same specimen against earth gravity. Hence, a low magnetic field strength results in a low More >

I. Ueno¹, T. Konisho², T. Kawase³, T. Watanabe⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 21-26, 2008, DOI:10.3970/fdmp.2008.004.021

Abstract The present authors carried out an experimental study with a special interest upon the dynamics of the fluid in the vicinity of the boundary line of three phases; solid-liquid-gas interface, which is so-called `contact line.' The moving droplet on the solid substrate is accompanied with the movement of the boundary line of three phases; solid-liquid-gas interface, which is so-called macroscopic 'contact line.' Existing studies have indicated there is a thin liquid film known as 'precursor film' ahead the contact line of the droplet. In the present study the precursor film was detected by applying conventional More >

V. Cristini¹, Y. Renardy²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.2, pp. 77-94, 2006, DOI:10.3970/fdmp.2006.002.077

Abstract We review studies of a drop of viscous liquid, suspended in another liquid, and undergoing breakup in an impulsively started shear flow. Stokes flow conditions as well as the effects of inertia are reported. They reveal a universal scaling for the fragments, which allows one to use sheared emulsions to produce monodispersity as an alternative to microfluidic devices. More >

Md. Abdul Halim¹, Asghar Esmaeeli²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.4, pp. 435-460, 2013, DOI:10.3970/fdmp.2013.009.435

Abstract This study aims to gain a detailed understanding of the transient behavior of solitary liquid drops in electric fields at finite Reynolds number. A front tracking/finite difference method, in conjunction with Taylor-Melcher leaky dielectric model, is used to solve the governing electrohydrodynamic equations. The evolution of the flow field and drop deformation is studied for a few representative fluid systems, corresponding to the different regions of the deformation-circulation map. It is shown that for the range of the physical parameters used here, the deformationtime history is governed by one time scale while the fluid flow More >

Davood Kalantari¹

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.2, pp. 169-182, 2013, DOI:10.3970/fdmp.2013.009.169

Abstract In this study, a critical summary of existing spray/wall interaction models is given in synergy with a review of available experimental data. In particular, special attention is devoted to the limitations, difficulties and complexities of the most used approaches in the literatures. An attempt is also made to indicate the bottlenecks and criticalities which typically arise when investigators try to extend results obtained for isolated droplets to the more complex dynamics produced by spray impacts. More >