Author(s)

Jose Manuel Redondo¹, Pilar Lopez Gonzalez-Nieto², Jose Leandro Cano³, German Andres Garzon¹

¹Applied Physics Department, Politecnica University of Cataluña (UPC), Barcelona, Spain.
²Applied Mathematics Department, Complutense University of Madrid (UCM), Madrid, Spain.
³Earth Physics, Astronomy and Astrophsics II Department, Complutense University of Madrid (UCM), Madrid, Spain.

Mixing generated by gravitational acceleration and the role of local turbulence measured through multifractal methods is examined in numerical experiments of Rayleigh-Taylor and Richtmyer-Meshkov driven front occurring at density interfaces. The global advance of the fronts is compared with laboratory experiments and Nusselt and Sherwood numbers are calculated in both large eddy simulation (LES) and kinematic simulation KS models. In this experimental method, the mixing processes are generated by the evolution of a discrete set of forced turbulent plumes. We describe the corresponding qualitative results and the quantitative conclusions based on measures of the density field and of the height of the fluid layers. We present an experimental analysis to characterize the partial mixing process. The conclusions of this analysis are related to the mixing efficiency and the height of the final mixed layer as functions of the Atwood number, which ranges from 9.8 × 10⁻³ to 1.34 × 10⁻¹.

Rayleigh-Taylor Instability, Richtmyer-Meshkov Instability, Mixing Efficiency, Front Evolution, Fractal Dimension

Redondo, J. , Gonzalez-Nieto, P. , Cano, J. and Garzon, G. (2015) Mixing Efficiency across Rayleigh-Taylor and Richtmeyer-Meshkov Fronts. Open Journal of Fluid Dynamics, 5, 145-150. doi: 10.4236/ojfd.2015.52017.