About possible mechanisms of influence of gas bubbles on characteristics of turbulent boundary layer
L.I. Maltsev, A.G. Malyuga, and B.G. Novikov
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Pages: 387-392
Abstract
Two different mechanisms responsible for the were revealed impact of gas bubbl injected into a boundary layer on the shear stress on the wetted surfaces. Both mechanisms exist due to extremely high sensitivity of bubbles even to very low pressure gradients and due to a high value of the virtual mass and coefficient of viscous drag for bubbles. The first mechanism manifests itself at the interaction of vortex structures with bubbles in the near-wall layer y+ < 250. The second mechanism is due to pressure gradient along the wetted surface. Ascertainment of these mechanisms explains the known discrepancies in the experimental results on gas saturation obtained on different experimental setups.
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