Sunil Punjabi¹, K. Muralidhar², P. K. Panigrahi²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.2, pp. 95-106, 2006, DOI:10.3970/fdmp.2006.002.095

Abstract Convection in a differentially heated two-layer system consisting of air and water was studied experimentally, using laser-interferometry. The cavity used for flow visualization was square in cross-section and rectangular in-plan having dimensions of 447 × 32 × 32 mm³. Experiments performed over different layer thicknesses of water filled in a square cross-section cavity, the rest being air, are reported in the present work. The following temperature differences for each layer height were imposed across the hot and the cold walls of the superposed fluid layers: (i) ΔT=10K and (ii)ΔT =18 K. The present study was aimed… 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 >

V. Pletser¹, R. Bosch², L. Potthast², R. Kassel³

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.1, pp. 65-76, 2006, DOI:10.3970/fdmp.2006.002.065

Abstract Orbital weightless conditions have been shown to yield better and larger crystals. The Solution Crystallization Diagnostics Facility (SCDF) is a third generation instrument developed by ESA and dedicated to the observation and study with advanced diagnostics nucleation and crystallisation processes of molecules from solutions on board the International Space Station. The SCDF is intended to be used for studies of proteins and large biomolecules, and more generally of any kind of molecules growing from solutions, using the powerful set of diagnostics means available in the SCDF platform. Several protein crystallisation reactors have been developed to More >

K. Matsunaga¹, H. Kawamura¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.1, pp. 59-64, 2006, DOI:10.3970/fdmp.2006.002.059

Abstract Existing studies on solidification phenomena mainly focused on the solidification processes per se. In real systems, however, one cannot neglect the effects of molten material convective flow, such as natural and thermocapillary convection (they strongly affect the resulting quality of the solidified materials). The present study aims to experimentally investigate on the effect of the thermocapillary flow upon the directional solidification in a liquid layer with a free upper surface. If no free surface exists, the solid--liquid interface (SLI) is vertical and straight, while, with the free surface, the SLI is inclined against the wall-normal More >

A.Kurenkov¹, A.Thess², H.Babovsky³

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.1, pp. 47-58, 2006, DOI:10.3970/fdmp.2006.002.047

Abstract A possibility for the determination of the interface between two electrically conducting fluids in cylindrical geometry is presented. The fluids with different conductivities are situated in an infinite cylinder. Along the axis of the cylinder a homogeneous electrical current is applied. The perturbation of the interface leads to an inhomogeneous electrical current and, therefore, results in an electrical potential change in the fluids and a magnetic field modification outside the fluids. The dependence of the electrical potential on the interface shape is obtained analytically. The interface profile is then recovered from data of the electrical More >

M. Kassemi¹, Y. Wang², S. Barsi^1,3, B.T.F. Chung²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.1, pp. 27-46, 2006, DOI:10.3970/fdmp.2006.002.027

Abstract Microgravity experiments, especially materials processing experiments, have often been hampered by presence of unwanted bubbles. In this work, the effect of thermocapillary convection generated by a bubble on the Bridgman growth of a dilute binary alloy in microgravity is investigated numerically. The model is based on the quasi-steady Navier-Stokes equations for the fluid flow in the melt coupled with the conservation equations for transport of energy and species in the growth ampoule. Numerical results indicate three different growth regimes based on the distance between the bubble and the growth interface: a diffusion dominated regime that More >

M.El-Gammal¹, J.M.Floryan¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.1, pp. 17-26, 2006, DOI:10.3970/fdmp.2006.002.017

Abstract Interface deformation and thermocapillary rupture in a cavity with free upper surface subject to concentrated heating from above is investigated. The dynamics of the process is modulated by placing different amounts of liquid in the cavity. The results determined for large Biot and zero Marangoni numbers show the existence of limit points beyond which steady, continuous interface cannot exist and processes leading to the interface rupture develop. Evolution of the limit point as a function of the mass of the liquid is investigated. The topology of the flow field is found to be qualitatively similar, More >

Milica Radisic^1,2, Gordana Vunjak-Novakovic³

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.1, pp. 1-16, 2006, DOI:10.3970/fdmp.2006.002.001

Abstract To engineer cardiac tissue in vitro with properties approaching those of native tissue, it is necessary to reproduce many of the conditions found in vivo. In particular, cell density must be sufficiently high to enable contractility, which implies a three-dimensional culture with a sufficient oxygen and nutrient supply. In this review, hydrogels and scaffolds that support high cell densities are examined followed by a discussion on the utility of scaffold perfusion to satisfy high oxygen demand of cardiomyocytes and an overview of new bioreactors developed in our laboratory to accomplish this task more simply. More >

J. Bahen¹, O. Gaber¹, K. Behdinan², J. De Beer³, P. Zalzal⁴, M. Papini¹, M. Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 343-352, 2005, DOI:10.3970/fdmp.2005.001.343

Abstract The penetration of the reamer into the medullary cavity can be compared to a piston entering a cylinder filled with viscous fluid. When the flutes of the reamer are clogged with bone debris, fat and marrow, the piston effect is magnified and larger pressures are usually obtained. This paper considers a reamer with clogged flutes and investigates whether the rotation speed of the reamer has a significant influence on the pressure within the intramedullary cavity. The effect of reamer rotation speed on the pressure distribution within the bone is investigated numerically by solving the full More >

M.H. Djavareshkian¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 329-342, 2005, DOI:10.3970/fdmp.2005.001.329

Abstract A pressure-based Euler scheme, based on a collocated grid arrangement is described. The newly developed algorithm has two new prominent features: (i) the use of normalized variables to bound the convective fluxes and (ii) the use of a high-resolution scheme in calculating interface density values to enhance the shock-capturing property of the algorithm. The algorithm is first tested for flows at different Mach numbers ranging from subsonic to supersonic on a bump in a channel geometry; then the results are compared with the corresponding ones obtained without the bounded scheme in the correction step. The More >