M. Marigo^1,2, D. L. Cairns¹, M. Davies¹, M. Cook³,A. Ingram^2,4,5, E. H. Stitt¹

CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.3, pp. 217-238, 2010, DOI:10.3970/cmes.2010.059.217

Abstract In this work the complex motion of the Turbulamixer has been measured by Multiple-Positron Emission Particle Tracking (Multiple PEPT) in order to set-up a DEM numerical model. Positron emitting radioactive tracers were attached to three of the pivot bearings on the shaft of the mixer to enable the rotation and translation of the mixer chamber to be tracked in the PEPT camera. The measured movement was mathematically reconstructed and imported into DEM in order to apply the same movement to the modelled vessel. The three-dimensional motion of particles in a vessel located in the Turbula mixer was then calculated using… More >

S. Aland¹, J. Lowengrub², A. Voigt¹

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.1, pp. 77-108, 2010, DOI:10.3970/cmes.2010.057.077

Abstract We present a new method for simulating two-phase flows in complex geometries, taking into account contact lines separating immiscible incompressible components. We combine the diffuse domain method for solving PDEs in complex geometries with the diffuse-interface (phase-field) method for simulating multiphase flows. In this approach, the complex geometry is described implicitly by introducing a new phase-field variable, which is a smooth approximation of the characteristic function of the complex domain. The fluid and component concentration equations are reformulated and solved in larger regular domain with the boundary conditions being implicitly modeled using source terms. The method is straightforward to implement… More >

M. Dandani^1,*, V. Lepiller², A. Ghezal³, P. Desevaux⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.1, pp. 23-37, 2018, DOI:10.3970/fdmp.2018.014.023

Abstract The present study deals with the numerical visualization of the mixing process in a 2D supersonic ejector. The mixing process is visualized using two CFD flow visualization methods. The first method consists in introducing discrete particles in the secondary flow and computing their trajectories. The second method consists in modeling the diffusion of a passive scalar introduced in one of the two flows. The mixing process is investigated in the case of a conventional 2D supersonic ejector and a second case of an ejector equipped with transverse micro jets. Flow visualizations obtained show the existence of a significant mixing enhancement… More >

H. Chanson¹, K.K. Tan²

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.4, pp. 403-418, 2011, DOI:10.3970/fdmp.2011.007.403

Abstract A tidal bore is a wall of water propagating upstream as the tidal flow turns to rising into an estuary with a tidal range larger than 5 to 6 m and the bathymetry that amplifies the tidal wave. The bore front is a shock characterised by a singularity of the free-surface and pressure and velocity fields. This study aims to characterise the impact of tidal bores on the turbulent dispersion of fish eggs. Some physical modelling was performed based upon a Froude similitude and the tracking of plastic beads acting as fish egg proxies was conducted under controlled flow conditions… More >

A. Benaissa¹, I. Yimer²

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.2, pp. 203-218, 2010, DOI:10.3970/fdmp.2010.006.203

Abstract This work presents a study on the effect of pulsing on a jet flow. Pulsing is used to modify jet inlet conditions with the objective of improving mixing. In this experimental work, a jet was slightly heated so that temperature could be considered as a passive scalar. The spectral behaviour of velocity and the passive scalar temperature was analyzed along the jet axis with and without pulsing. Low frequency pulsing (f/fS< 0.05 fSthe Strouhal frequency) modifies the spectral composition of the velocity at the jet exit, but it does not affect the asymptotic profile reached in the fully developed region… More >

N. Armour¹, S. Dost^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 331-344, 2009, DOI:10.3970/fdmp.2009.005.331

Abstract A combined numerical and experimental investigation has been undertaken to explore the benefits of an applied static magnetic field on Silicon transport into a Germanium melt. This work utilized a similar material configuration to that used in the Liquid Phase Diffusion (LPD) and Melt-Replenishment Czochralski (Cz) growth systems. The measured concentration profiles from the samples processed with and without the application of magnetic field showed very similar shape. The amount of silicon transport into the melt is slightly higher in the samples processed under magnetic field, and there is a substantial difference in dissolution interface shape indicating a change in… More >