M. Hennenberg¹, B. Weyssow², S. Slavtchev³, B. Scheid⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.4, pp. 295-302, 2007, DOI:10.3970/fdmp.2007.003.295

Abstract A horizontal thin layer of ferrofluid is bordered by a solid and open to an inert gas on the other side. It is submitted to a heat gradient and a weak magnetic field, both being normal to the free deformable surface, leading to a coupling between the Marangoni phenomenon, induced by the variation of surface tension along the free deformable surface and the isothermal Cowley-Rosensweig problem, consequence of the magnetic field. The study of the steady compatibility condition shows a new pattern of stationary instability. The critical wavenumber is of O(√Bo), the Bond number Bo being More >

Rodica Borcia^1,2, Michael Bestehorn²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.4, pp. 287-294, 2007, DOI:10.3970/fdmp.2007.003.287

Abstract We developed a phase field model for Marangoni convection in compressible fluids of van der Waals type far from criticality. The theoretical description is based on the Navier-Stokes equation with extra terms responsible for describing the Marangoni effect, the classical heat equation, and the continuity equation. The model previously developed for a two-layer geometry is now extended to drops and bubbles. Finally, we report on 2D numerical simulations for drop Marangoni migration in a vertical temperature gradient. More >

Srikrishna Sahu¹, K. Muralidhar¹, P.K. Panigrahi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 265-286, 2007, DOI:10.3970/fdmp.2007.003.265

Abstract Convection in a differentially heated cavity partly filled with silicone oil has been experimentally studied. The air-oil layers are subjected to a temperature difference in the vertical direction, with the lower wall being heated with respect to the top. The overall geometry is that of an enclosed cavity that is octagonal in plan. Heights of oil layers considered for experiments correspond to 30, 50, and 70% of the vertical cavity dimension. Measurements have been carried out using a shadowgraph technique. A limited number of interferograms have also been recorded. The shadowgraph technique has been validated… More >

Joseph G. Lawrence, John P. Dismukes, Arunan Nadarajah¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 255-264, 2007, DOI:10.3970/fdmp.2007.003.255

Abstract The atmospheric chemical vapor deposition process on continuous glass sheets is a well developed one and the parameters that affect it are relatively well understood. When this process is converted to coat discrete glass plates it introduces a new variable, the gap between the glass plates, which can significantly impact the quality of the coatings. In this study a 2D pseudo steady state model of the process was developed to study the effect of the gap, and the ratio of outlet to inlet gas flow rates (called the bias), on the coating quality. The model… More >

Joseph G. Lawrence, Arunan Nadarajah¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 247-254, 2007, DOI:10.3970/fdmp.2007.003.247

Abstract A simplified 2D pseudo steady state model was developed for an atmospheric chemical vapor deposition (CVD) process on glass. This is used to study the feasibility of converting a continuous coating process to one with discrete glass plates with a gap between them. A preliminary estimate employing mass transfer correlations suggested that there would be significant concentration variations due to the gap between the plates. More detailed studies were done by solving the model numerically employing a finite difference scheme with a vorticity-stream function formulation, and employing the commercial computational fluid dynamics program FIDAP which… More >

Y. Yan¹, K. Jules², M. Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 231-246, 2007, DOI:10.3970/fdmp.2007.003.231

Abstract Fluid science research including thermal diffusion in fluids benefits from the quiescent low-gravity environment provided by the International Space Station (ISS). However, residual gravities (or g-jitters) aboard the ISS impact the overall environment in which experiments are being performed. The impact of these residual gravities needs to be assessed to ensure that they are appropriately accounted for when results are being reported for experiments performed onboard the ISS. In this paper we study the thermal diffusion process in a ternary mixture of n-butane, dodecane and methane. Measured data from the Space Acceleration Measurement System (SAMS)… More >

Akira Hirata¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 203-230, 2007, DOI:10.3970/fdmp.2007.003.203

Abstract This article is a summary of author's typical research works (over the last four decades) on interphase transport phenomena in the presence of interfacial fluid motion and surface tension gradients on liquid-fluid interfaces, and related applications to single crystal growth and microgravity sciences. A unified theory for momentum, heat and mass transfer on liquid-fluid and solid-fluid interfaces is proposed, which takes into account interface mobility. It is shown that interface contamination and turbulence can be well explained, respectively, by suppression and enhancement of the interfacial velocity induced by surface tension gradients. Transport phenomena on solid More >

B. Obradovic¹, M. Radisic², G. Vunjak-Novakovic³

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 189-202, 2007, DOI:10.3970/fdmp.2007.003.189

Abstract Efficient transport of oxygen is one of the main requirements in tissue engineering systems in order to avoid cell death in the inner tissue regions and support uniform tissue regeneration. In this paper, we review approaches to design of tissue engineering systems with adequate oxygen delivery for cultivation of cartilage and myocardium, two distinctly different tissue types with respect to the tissue structure and oxygen requirements. Mathematical modeling was used to support experimental results and predict oxygen transport within the cultivated tissues and correlate it to the cell response and tissue properties. More >

R. Prud’homme¹, M. El Ganaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.2, pp. 161-172, 2007, DOI:10.3970/fdmp.2007.003.161

Abstract Some problems related to solid/liquid phase change are presented. Attention is focused on interface modeling for numerical analysis and one-dimensional directional growing and melting. Microgravity relevance of some situations is emphasized. It is shown, in particular, that in some circumstances melting is not the simple reversal of crystal growth due to some (still poorly known) phenomena (nucleation and growth of liquid droplets in the bulk, solid and liquid dendrites due to a morphological instability of the phase boundary). Relevant mathematical models are discussed and described (to a certain extent) for analysis and/or characterization of these More >

Y. Kamotani¹, S. Matsumoto², S. Yoda²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.2, pp. 147-160, 2007, DOI:10.3970/fdmp.2007.003.147

Abstract A Marangoni Convection Modeling Research group was formed in Japan in order to investigate oscillatory thermocapillary flow systematically over a wide range of Prandtl number (Pr). The research by the group represents the current status of the subject. The present article reports the work done by the group members. The work is divided into three Pr ranges (low, medium and high) because the cause of oscillations is different in each range. For the low-Pr case, the transition to oscillatory flow is preceded by a steady bifurcation to three-dimensional convection. For the first time an experimental More >