Theoretical Physics

Rayleigh-Benard Convection; Lattice Boltzmann Methods

A major portion of Dr. Haowen Xi's research in the rich physics of spatially extended non-equilibrium systems, and especially in the dynamics of spatiotemporal chaos which occurs widely in fluid, chemical, laser, and biological systems. A major thrust of the research is to understand the complex behavior of far from equilibrium systems. This research involves studies of thermodynamic descriptions of non-equilibrium transitions in Rayleigh-Benard systems. We study simplified nonlinear models and develop conceptual insight from numerical results. This work entails implementing efficient numerical methods for simulating large scale non-equilibrium systems and supercomputer simulations in CRAY C-90 and CM-5 parallel computers.

Another area of Xi's research is the development and application of advanced computer simulation techniques (e.g. Lattice-Boltzmann method) in the studies of multiphase fluid flow through porous media and in polymer droplets breakup and coalescence in a mixing shear flow. The understanding of multiphase fluid flow, and transport and reaction in porous media, has direct applications for solution driven oil recovery.

Recent publications:

1) Bruno Ullrich, Haowen Xi, "Photocurrent limit in nanowires" Optics Letters, 38, 22 (2013) 4698-4700

2) Bruno Ullrich, Haowen Xi, "Photocurrent theory based on coordinate dependent lifetime" Optics Letters, 35, 23 (2010), 3910-3912

• Rayleigh-Behard Convection; Lattice Boltzmann Methods