Past Research

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My Ph.D. and postdoctoral research was in the field of non-linear dynamics, instabilities, and turbulence. One central problem in this field is the emergence of patterns in time and space in nonlinear systems driven out of equilibrium. In this framework, we established the existence and dynamics of coherent structures originating from boundary layer instabilities in turbulent convection (Fig. 1).

Fig. 1. Boundary layer instabilities in turbulent Rayleigh-Benard convection generate thermal plumes. This visualization uses thermochromic liquid crystals in water. The Rayleigh number is 109, in a cubic cell of 18.5 cm side. The size of the plume is about 1.5 cm [Physica A 166, 387 (1990)].

Later we obtained the scaling behavior in the inertial and dissipative range for the highest Reynolds number turbulence obtained in a controlled laboratory experiment (Fig. 2), among other results.

Fig. 2. Power spectrum of the velocity fluctuations in a mechanically driven turbulent flow in low temperature He gas. The Reynolds number is Re » 1.2 ´ 106; the detector size is 7 mm. The peak at k » 1 cm-1 corresponds to the energy injection scale; the scaling range extends over more than two decades, and the dissipative range is resolved [Phys. Rev. E 50, 3693 (1994)].

The most astounding persistent pattern in non-equilibrium systems is life. While at the Niels Bohr Institute in Denmark, I turned my research towards molecular biophysics, which is my main research interest now.