Numerical modelling of electromagnetically-driven turbulent flows using LES methods

F. Felten , Yves Fautrelle (1) , Y. Du Terrail , Olivier Métais (2)

1 LTPCM - Laboratoire de thermodynamique et physico-chimie métallurgiques
2 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]

We deal with the prediction of electromagnetically-driven turbulent flows by means of a large-eddy-simulation method (LES). The model is applied in the case of a liquid metal pool submitted to a polyphase linear electromagnetic stirrer. We investigate two cases: (i) the effects of the pulsating part of the Lorentz forces are neglected, the frequency of the applied magnetic field being high enough; (ii) the oscillating part of the electromagnetic forces is taken into account, the frequency of the magnetic field being sufficiently low. The LES predictions agree well with the mean velocity measurements, as does the standard k–ε model. However, as for the turbulent kinetic energy predictions, there is a large discrepancy between the two models. When the oscillating part of the Lorentz forces is taken into account, the computations show that the fluid flow is sensitive to the unsteady part of the forces provided the frequency of the magnetic field is sufficiently low. The mean velocity is not affected by the fluctuating component of the force. As for the turbulence parameters, the presence of the pulsating part leads to a significant reduction of the turbulent kinetic energy, whilst the turbulence length scale decreases. The effect of the oscillating part of the Lorentz forces becomes negligible when the magnetic field frequency exceeds approximately 5 Hz.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

F. Felten, Yves Fautrelle, Y. Du Terrail, Olivier Métais. Numerical modelling of electromagnetically-driven turbulent flows using LES methods. Applied Mathematical Modelling, 2004, 28, pp.15-27. ⟨10.1016/S0307-904X(03)00116-1⟩. ⟨hal-00265148⟩