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 >

I. Ueno¹, A. Kawazoe², H. Enomoto³

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.1, pp. 99-108, 2010, DOI:10.3970/fdmp.2010.006.099

Abstract The authors focus on thermocapillary-driven flow in a half-zone liquid bridge and its transition from two-dimensional steady flow to three-dimensional oscillatory one under an effect of forced convection in ambient gas region around the liquid bridge. The liquid bridge is settled in a cylindrical 'external shield,' in which upward/downward forced flow of the ambient gas is added. The critical condition of the flow transition in the 2-cSt silicone-oil liquid bridge is examined as functions of the aspect ratio and the volume ratio of the liquid bridge, and averaged velocity of the ambient gas. The authors indicate a significant effect of… More >

Yu. Gaponenko¹, I. Ryzhkov², V. Shevtsova³

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.1, pp. 75-98, 2010, DOI:10.3970/fdmp.2010.006.075

Abstract Gas-liquid flows in annulus are analyzed for fluids in large range of viscosity ratios. The geometry corresponds to a liquid bridge co-axially placed into an outer cylinder with solid walls. The internal core consists of solid rods at the bottom and top, while the central part is a relatively short liquid zone filled with viscous liquid and kept in its position by surface tension. The gas enters into the annular duct and entrains initially quiescent liquid. The flow structures in the liquid and gas are obtained numerically for different shapes of solid rods. Solution for fully developed flow in annulus… More >

V. Shevtsova^1,2, A. Mialdun¹, C. Ferrera^1,4, M. Ermakov^3,4, J. M. Montanero⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 43-54, 2008, DOI:10.3970/fdmp.2008.004.043

Abstract Dynamic free surface deformations induced by buoyant and thermocapillary convection in liquid bridges of 5cSt silicone oil are studied experimentally and numerically. The experiments are performed in ground conditions and static deformation is unavoidable. Convective motion starts in the liquid bridge as soon as ΔT ≠ 0 and initially leads to a stationary dynamic deformation of the free surface. Oscillatory motion starts at a critical value of ΔT and causes oscillations of the interface. The final supercritical shape of the free surface is a result of the static shape with superimposed subcritical stationary and oscillatory dynamic deformations. All these contributions… More >

A. Laverón-Simavilla¹, V. Lapuerta¹, J. Rodríguez¹, M. A. González¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.4, pp. 339-348, 2007, DOI:10.3970/fdmp.2007.003.339

Abstract A cylindrical liquid bridge supported between two circular-shaped disks in isorotation is considered. The effect of an offset between the rotation axis and the axis of the two supporting disks (eccentricity) on the stability of the liquid bridge is investigated. In a previous work a numerical method used to determine the stability limit for different values of eccentricity was validated comparing these results with analytical and experimental results for small eccentricity values, recovering the same behavior. In this work we use the numerical method to extend the analysis to large values of the eccentricity, finding a change in the bifurcation… More >

D.E. Melnikov¹, V.M. Shevtsova²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.4, pp. 329-338, 2007, DOI:10.3970/fdmp.2007.003.329

Abstract Thermocapillary convection in a long vertical liquid column (called liquid bridge) subjected to heating from above is considered for a three-dimensional Boussinesq fluid. The problem is solved numerically via finite-volume method. Full system of three dimensional Navier-Stokes equations coupled with the energy equation is solved for an incompressible fluid. Instability sets in through a wave propagating in axial direction with zero azimuthal wave number, which is a unique stable solution over a wide range of supercritical heating. Further increasing the applied temperature difference results in bifurcation of a second wave traveling azimuthally with a slightly higher frequency. The two waves… 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 proof of this first transition… More >

M. P. Muthuraj^1,2, K. Nithyapriya¹

CMC-Computers, Materials & Continua, Vol.48, No.2, pp. 119-132, 2015, DOI:10.3970/cmc.2015.048.119

Abstract The maintenance, upgrading and replacement of existing bridges have become urgent requirement and a challenging task for the construction sector. Bridge decks made of fibre reinforced polymers (FRP), have been widely adopted both in new construction and replacement of existing bridge decks. This paper reports the studies carried out hand lay-up multicellular glass fibre reinforced polymer. Multicellular bridge deck panels with various cross sectional profiles have been analysed using a general purpose finite element software ANSYS. A cross sectional profile that satisfied the deflection criteria with minimum weight was selected for analysis and fabrication. Six multicellular GFRP composite bridge deck… More >

Qunfeng Liu¹, gping Shen²

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 59-76, 2010, DOI:10.3970/cmc.2010.017.059

Abstract Molecular Dynamics (MD) simulations have been performed using the EAM potential to investigate the deformation behaviors and mechanical properties of <100>/{100} gold nanowires with square cross-section at a certain strain rate under different temperatures ranging from 10 K to 700 K. It is found that <100>/{100} gold nanowires at high temperatures tend to form the extended stable nanobridges-Helical Multi-shell Structure (HMS), which is similar to the deformation behavior of <110> gold nanowires at room temperature reported in the previous experimental observations and simulations. The effect of temperature on the mechanical properties and deformation behaviors of gold nanowires was analyzed. The… More >