Title of article :
Electromagnetic flow control of a bifurcated jet in a rectangular cavity
Author/Authors :
Kalter، نويسنده , , R. and Tummers، نويسنده , , M.J. and Kenjere?، نويسنده , , S. and Righolt، نويسنده , , B.W. and Kleijn، نويسنده , , C.R.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2014
Abstract :
The effect of Lorentz forcing on self-sustained oscillations of turbulent jets (Re = 3.1 × 103) issuing from a submerged bifurcated nozzle into a thin rectangular liquid filled cavity was investigated using free surface visualization and time-resolved particle image velocimetry (PIV). A Lorentz force is produced by applying an electrical current across the width of the cavity in conjunction with a magnetic field. As a working fluid a saline solution is used. The Lorentz force can be directed downward ( F L < 0 ) or upward ( F L > 0 ) , to weaken or strengthen the self-sustained jet oscillations. The low frequency self-sustained jet oscillations induce a free surface oscillation. When F L < 0 the amplitude of the free surface oscillation is reduced by a factor of 6 and when F L > 0 the free surface oscillation amplitude is enhanced by a factor of 1.5.
e fraction of the turbulence kinetic energy k = 1 2 u i ′ u i ′ ‾ is due to the self-sustained jet oscillations. A triple decomposition of the instantaneous velocity was used to divide the turbulence kinetic energy into a part originating from the self-sustained jet oscillation k osc and a part originating from the higher frequency turbulent fluctuations k turb . It follows that the Lorentz force does not influence k turb in the measurement plane, but the distribution of k osc can be altered significantly. The amount of energy contained in the self-sustained oscillation is three times lower when F L < 0 compared to the situation with F L > 0 .
Keywords :
Electrohydrodynamics (EHD) , Continuous steel casting , Proper orthogonal decomposition (POD) , Self-sustained oscillations , cavity flow , Flow Control
Journal title :
International Journal of Heat and Fluid Flow
Journal title :
International Journal of Heat and Fluid Flow