Measurements of molecular mixing in a high-Schmidt-number Rayleigh–Taylor mixing layer

Scalar dissipation fronts in high-Schmidt number mixing.

Jörg Schumacher Fachbereich Physik, Philipps-Universität Marburg, D-35032 Marburg, Germany Herwig Zilken Visualization Laboratory, Zentralinstitut für angewandte Mathematik, Forschungszentrum Jülich, D-52425 Jülich, Germany Bruno Eckhardt Fachbereich Physik, Philipps-Universität Marburg, D-35032 Marburg, Germany Katepalli R. Sreenivasan International Centre for Theoretical Physics, 34014 Triest...

Statistics and geometry in high-Schmidt number scalar mixing

The mixing of substances is present in various turbulent systems. Examples arise in reacting flows and combustion, mixing of salt and plankton in oceans and of chemical pollutants in the stratosphere [1]. The physics of scalar mixing depends strongly on the ratio of the kinematic viscosity ν of the fluid to the diffusivity κ of the scalar. It is given by the Schmidt number Sc = ν/κ. For the fol...

On filtering in the viscous-convective subrange for turbulent mixing of high Schmidt number passive scalars

Mixing at large Schmidt number in the self-similar far field of turbulent jets

We present results from an experimental investigation of turbulent transport and molecular mixing of a Sc S 1 conserved scalar in the fully developed self-similar far field of a steady, axisymmetric, momentum-driven, free turbulent jet issuing into a quiescent medium. Our experiments cover the axial range from the jet exit to 350 diameters downstream, and span the range of Reynolds numbers from...

Vertical mixing layer development

A new generation of current and wave testing tanks is required to simulate more realistic sea conditions at larger scales. One means of producing a current is by using groups of impellers arranged around the perimeter of a circular tank. Each propeller produces a single flow velocity which may be different to its neighbours. These differences can lead to a stepped or curved plan view velocity p...