Current Research Topics

  • Two-phase flows


Phase interface in a turbulent hydraulic jump
(Milad Mortazavi, Dokyun Kim, and Ali Mani)

The objective of this project is to develop an understanding of the surface breaking, air entrapment, and in particular micro-bubble generation due to interactions between turbulence and free-surfaces. While direct numerical simulation of micro-bubbles (10-100 microns) is prohibitively expensive in a large scale turbulent flow calculation, numerical tools can be used to probe the local flow/interface scenarios hospitable for micro-bubble generation. Statistical analysis of the turbulent flow regimes and chaotic interfaces enables determination of relative importance of possible mechanisms for small bubble generation including bubble fragmentation and thin film breakup.

  • Nonlinear electrokinetics


Brownian dynamic simulation of deionization shocks
(Ali Mani, Martin Bazant)

Shown is the evolution of counter-ions (red) and co-ins (blue) in a microchannel with charged walls subject to an external axial electric field. The nonlinear behavior is due to the exchange of ions between the bulk and the electric double layers (EDLs). An initial bulk depletion at one end of the channel triggers strong EDL transport leading to the formation of concentration shocks. The shock leaves behind a region of ultra pure fluid acting to deionize the bulk. For more information see Mani, Zangle and Santiago (2009) and Mani and Bazant (2011). Current work focuses on the extension of these concepts to geometrically complex structures such as porous media.