K.S. Kim¹, B.H. Lee², M.H. Kim¹, J.C. Park³

CMES-Computer Modeling in Engineering & Sciences, Vol.79, No.3&4, pp. 201-222, 2011, DOI:10.3970/cmes.2011.079.201

Abstract The coupling and interactions between vessel motion and inner-tank sloshing are investigated by a potential-CFD (Computational Fluid Dynamics) hybrid method in time domain. Potential-theory-based 3D diffraction/radiation panel program is used to obtain the hydrodynamic coefficients and wave forces for the simulation of vessel motion in time domain. The liquid sloshing in tanks is simulated in time domain by using the improved Moving Particle Simulation (PNU-MPS) method and it is validated through comparison against sloshing experiments. The calculated sloshing tank forces and moments are applied to the vessel-motion simulation as excitation forces and moments. The updated… 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… More >

V. Shevtsova¹, A. Mialdun¹, H. Kawamura², I. Ueno², K. Nishino³, M. Lappa⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 1-28, 2011, DOI:10.3970/fdmp.2011.007.001

Abstract The experimental results from nine benchmark test cases conducted by five different groups are presented. The goal of this study is to build an experimental database for validation of numerical models in liquid bridge geometry. The need arises as comparison of numerical results with a single experiment can lead to a large discrepancy due to specific experimental conditions. Perfectly conducting rigid walls and, especially, idealized boundary conditions at the free surface employed in numerical studies are not always realized in experiments. The experimental benchmark has emphasized strong sensitivity of the threshold of instability to the More >

Li Chen, Hui-Bao Luan, Wen-Quan Tao^*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-11, 2010, DOI:10.5098/hmt.v1.2.3002

Abstract Multi-phase lattice Boltzmann method is applied to investigate liquid water transport in th GDL and GC. The liquid water transport processes in the GDL, near the GDL-GC interfaces and in the GC are discussed. The effects of channel land on liquid water dynamic behaviors and distribution in the GDL and GC are investigated. It is found that channel land covers the GDL-GC interface where liquid water reaches changes the water distribution near the GDL-GC interface and in the GC. While channel land is apart from the GDL-GC interface where liquid water reaches changes the effects More >

H.W. Zhang^1,2, J. Lv¹, Y.G. Zheng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.68, No.1, pp. 55-94, 2010, DOI:10.3970/cmes.2010.068.055

Abstract A new multiscale computational method named as extended multiscale finite element method is proposed for the mechanical analysis of closed liquid cell materials. The numerical base functions for both the displacement field and the pressure of the incompressible fluid within the closed cells are employed to establish the relationship between the macroscopic deformation and the microscopic variables such as deformation, stress, strain and fluid pressure. The results show that the extended multiscale finite element method constructed with the conventional four-node quadrilateral coarse-grid elements sometimes will have strong boundary effects and cannot predict well the fluid… More >

Chun-Lang Yeh¹

CMES-Computer Modeling in Engineering & Sciences, Vol.67, No.3, pp. 175-210, 2010, DOI:10.3970/cmes.2010.067.175

Abstract Previous studies of nano-scale liquid threads have almost entirely been devoted to the investigation of a single liquid thread in a periodic fundamental cell. This paper is the first to study the vaporization process of two nano-scale liquid threads coexisting in a periodic fundamental cell by molecular dynamics (MD) simulation. Because of the interaction between the two liquid threads, the vaporization process is different from that of a single liquid thread in a periodic fundamental cell. This study discusses the influences of the liquid thread radius, fundamental cell length, and relative position of the two… More >

K. Kakuda¹, Y. Ushiyama¹, S. Obara¹, J. Toyotani¹, S. Matsuda², H.Tanaka², K. Katagiri²

CMES-Computer Modeling in Engineering & Sciences, Vol.66, No.3, pp. 215-226, 2010, DOI:10.3970/cmes.2010.066.215

Abstract The application of the MPS (Moving Particle Semi-implicit) scheme to incompressible viscous fluid flow problem in the liquid ring vacuum pump with rotating impeller is presented. The rotating impeller in the pump is attached to a center hub and located in off-set from the center of a cylindrical body. For such flow problem there are some interesting phenomena including the formation of the liquid ring by rotating impeller, the interface dynamics between gas and liquid, and so forth. The MPS scheme is widely utilized as a particle strategy for the free surface flow, the problem More >

S. Hamimid¹, A.Amroune¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.4, pp. 369-384, 2010, DOI:10.3970/fdmp.2010.006.369

Abstract The Navier-Stokes and energy equations are numerically solved to investigate two-dimensional convection (originating from the combined effect of buoyancy and surface tension forces) in a liquid metal subjected to transverse magnetic fields. In particular, a laterally heated horizontal cavity with aspect ratio (height/width) =1 and Pr=0.015 is considered (typically associated with the horizontal Bridgman crystal growth process and commonly used for benchmarking purposes). The effect of a uniform magnetic field with different magnitudes and orientations on the stability of the two distinct convective solution branches (with a single-cell or two-cell pattern) of the steady-state flows More >

Nedeltcho K,ev¹, Val Kagan², Ahmed Daoud¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.3, pp. 291-318, 2010, DOI:10.3970/fdmp.2010.006.291

Abstract Results are presented of 3D numerical magneto-hydrodynamic (MHD) simulation of electromagnetic DC pump for both laminar and turbulent metal flow under an externally imposed strongly non-uniform magnetic field. Numerous MHD flow cases were simulated using finite element method and the results of five typical examples are summarized here, including one example of laminar brake flow, one example of turbulent brake flow and three examples of turbulent pumping conditions. These simulations of laminar and turbulent channel flow of liquid metal correctly represent the formation of an M shaped velocity profile and are in good agreement with… 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, More >