Qiang Li¹, Jie Ouyang¹, Guorong Wu¹, Xiaoyang Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.82, No.3&4, pp. 215-232, 2011, DOI:10.32604/cmes.2011.082.215

Abstract The governing equations of two-phase flows including gas and polymer melt are presented, which are solved using finite volume and domain extension methods with SIMPLEC technology. The melt filling and primary gas penetration in gas-assisted injection molding (GAIM) process are simulated, where the Cross-viscosity model is employed to describe the melt rheological behavior, and the CLSVOF(coupled Level Set and Volume of fluid) method is employed to capture the moving interfaces. In order to test and verify the coupled methods, melt filling in a rectangular plate with an insert is simulated, and the numerical results are in good agreement with those… More >

Zhentao Wang^1,*, Kai Dong, Shuiqing Zhan

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.4, pp. 221-234, 2017, DOI:10.3970/fdmp.2017.013.221

Abstract We have investigated the unsteady internal flow occurring in an evaporating droplet interacting with a high-temperature atmospheric environment. The Navier-Stokes equations for both the liquid and the gas phases have been solved numerically in the framework of a Volume of Fluid (VOF) method relying on the so-called Continuum Surface Force (CSF) model. A specific kernel able to account for evaporation and related phase change has been incorporated directly in the VOF approach. The temperature distributions within the droplet has been found to be relatively uniform by virtue of the Marangoni flow. The transient evolution of the flow pattern and related… More >

R. Savino¹, M . Visone², D. Rossetto³, V. D'Oriano⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.4, pp. 331-341, 2015, DOI:10.3970/fdmp.2015.011.331

Abstract This paper presents two applications of Computational Fluid Dynamics (CFD) to super and mega yacht design, based on the Volume of Fluid method. After an overview of recent literature on the subject, the analysis of the hydrodynamic performances of different hull configurations and of different appendage configurations is presented. More >

Chekifi. T^1,2, Dennai. B¹, Khelfaoui. R¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 205-220, 2015, DOI:10.3970/fdmp.2015.011.205

Abstract Droplet generation, splitting and sorting are investigated numerically in the framework of a VOF technique for interface tracking and a finite-volume numerical method using the commercial code FLUENT. Droplets of water-in-oil are produced by a flow focusing technique relying on the use of a microchannell equipped with an obstacle to split the droplets. The influence of several parameters potentially affecting this process is investigated parametrically towards the end of identifying "optimal" conditions for droplet breakup. Such parameters include surface tension, the capillary number and the main channel width. We show that the capillary number plays a crucial role in determining… More >

D. Bothe^1,2, M. Kröger¹, H.-J. Warnecke³

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.3, pp. 303-316, 2011, DOI:10.3970/fdmp.2011.007.303

Abstract In this paper numerical results on reactive mass transfer from single gas bubbles to a surrounding liquid are presented. The underlying numerical method is based on the solution of the incompressible two-phase Navier-Stokes equations. The Volume-of-Fluid method is applied for the description of the liquid-gas interface. Within the numerical approach the concentration of the transfer component is represented by two separate variables, one for each phase. Numerical results are in good agreement with experimental data. More >

A. Alke¹, D. Bothe¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 345-372, 2009, DOI:10.3970/fdmp.2009.005.345

Abstract We present a computational approach based on the Volume-of-Fluid (VOF) method for simulating the influence of a soluble surfactant on the behavior of two-phase systems with deformable interface. Our approach is applicable to diffusion controlled processes, where the relation between the area-specific excess surfactant concentration on the interface and the volume-specific concentration adjacent to the interface is given by an adsorption isotherm. Main issues of the numerical model are an extended surface transport theorem used for describing the interfacial flux and an iso-surface of the VOF-variable used as a connected approximation for the interface. 3D-simulations of a bubble moving through… More >

M.H. Djavareshkian¹, M. Khalili²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.4, pp. 299-308, 2006, DOI:10.3970/fdmp.2006.002.299

Abstract This paper opens a new horizon on the simulation of sloshing phenomena. One of the most popular Finite Volume methods called VOF (Volume Of Fluid) method is used for tracking the flow in containers. The algorithm is tested for different fluid elevations, physical conditions in different road curves and liquid properties. The method is then validated against an analytical and another numerical solution. These comparisons show that the VOF can effectively solve the sloshing problem for different fluids and a variety of physical and geometrical conditions. More >

Marcello Lappa¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.2, pp. 141-152, 2006, DOI:10.3970/fdmp.2006.002.141

Abstract Numerical simulations and computer-graphics animation can be used as useful tools to discern the physicochemical environmental factors affecting the surface kinetics of growing biological tissues as well as their relative importance in determining growth. A mathematical formalism for such kinetics is proposed through parametric investigation and validated through focused comparison with experimental results. The study relies on the application of a CFD moving boundary (Volume of Fluid) method specially conceived for the simulation of these problems. In the second part of the analysis the case of two samples hydrodynamically interacting in a rotating bioreactor is considered. The interplay between two… More >

Xiaofeng Yang¹, Ashley J. James^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.1, pp. 65-96, 2007, DOI:10.3970/fdmp.2007.003.065

Abstract An arbitrary Lagrangian-Eulerian (ALE) method for interfacial flows with insoluble surfactants is presented. The interface is captured using a coupled level set and volume of fluid method, which takes advantage of the strengths of both the level set method and the volume of fluid method. By directly tracking the surfactant mass, the method conserves surfactant mass, and prevents surfactant from diffusing off the interface. Interfacial area is also tracked. To accurately approximate the interfacial area, the fluid interface is reconstructed using piece-wise parabolas. The surfactant concentration, which determines the local surface tension through an equation of state, is then computed… More >

Marcello Lappa ¹

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 51-64, 2005, DOI:10.3970/cmc.2005.002.051

Abstract A possible approach for the investigation of a number of aspects related to the processing of immiscible alloys, made possible by recent progress in both fields of moving boundary (VOF) methods and speed of computers, is discussed. It can capture in a single numerical treatment and without limiting assumptions both macroscopic information (i.e. the macrophysical problem, heretofore treated in terms of population dynamics) and microscopic details (i.e. the microphysical problem, heretofore treated within the framework of boundary integral methods and/or under the assumption of nondeformable drops). The role played by coalescence in changing the Marangoni migration velocity is discussed together… More >