Influence of Gas Turbulence on the Instability of an Air-Water Mixing Layer

Jean-Philippe Matas (1) , Sylvain Marty (1) , Mohamed Seydou Dem (1) , Alain H. Cartellier (1)

1 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]

We present the first evidence of the direct influence of gas turbulence on the shear instability of a planar air-water mixing layer. We show with two different experiments that increasing the level of velocity fluctuations in the gas phase continuously increases the frequency of the instability, up to a doubling of frequency for the largest turbulence intensity investigated. A modified spatiotemporal stability analysis taking turbulence into account via a simple Reynolds stress closure provides the right trend and magnitude for this effect.

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

Jean-Philippe Matas, Sylvain Marty, Mohamed Seydou Dem, Alain H. Cartellier. Influence of Gas Turbulence on the Instability of an Air-Water Mixing Layer. Physical Review Letters, 2015, 115 (7), ⟨10.1103/PhysRevLett.115.074501⟩. ⟨hal-01212562⟩