Abstract: Nowadays, computational fluid dynamics (CFD) becomes more and more mature. In the same time, it becomes more and more difficult to contribute fundamental research to it. The fact that commercial CFD software is a success is proof of the practical importance of the theoretical fluid-dynamics works since Euler. The growing availability of CFD software may seem to be a threat for CFD research. However, how CFD develops remain unpredictable, and it is part of what makes it an exciting and attractive discipline.
This paper aims to exhibit a synthesis of some recent works in CFD. It concerns the turbulence problem in mixing media. The mixing theory appears in an area with far from complete solving problems: the flow kinematics. Its methods and techniques developed the significant relation between turbulence and chaos. The turbulence is an important feature of dynamic systems with few freedom degrees, the so-called “far from equilibrium systems”. These are widespread between the models of excitable media, and a recent goal is to find a consistent and coherent theory to stand up that a mixing model in excitable media leads to a far from equilibrium model.
Studying a mixing for a flow implies the analysis of successive stretching and folding phenomena for its particles, the influence of parameters and initial conditions. In the previous works [1,2,3,4,5], the study of the 3D non-periodic models exhibited a quite complicated behavior. In agreement with experiments, they involved some significant events - the so-called “rare events”. The variation of parameters had a great influence on the length and surface deformations.
The experiments were realized with a special vortex installation [7], it was used a well-known aquatic algae as biologic material, and the water as basic fluid. It must be noticed that both the experimental an analytical analysis work for any biological material.
In the paper there are presented a qualitative synthesis analysis, with the corresponding graphical simulations, for the periodic (2D) and non-periodic (3D) flow case. It was used the numeric soft Maple11, with its powerful and fast analysis and numeric tools. The statistical cases are very few (especially in 3D case), and it is pointed out the “rare event” new concept.

Brief Biography of the Speaker:
I am associate professor in the Department of Applied Sciences and Environment Protection at the Faculty of Engineering and Management of Technological Systems, University of Craiova, Romania. I received my PhD in Industrial Engineering, at the Department of Engineering of Biotechnical Systems of the Polytechnic University of Bucarest, Romania, where I spent an academic and research stage. My research interests include computational fluid dynamics, especially on the turbulent mixing area, and the interface between the fluid dynamics and computational tools, including adequate software tools. Also optimization methods in the differential equations modeling intelligent flows moving in an actuator, and the interface with magneto-hydro-dynamics are among my recent skills.
I am member of ESF (European Scientific Foundation) database, member of IAENG (International Association of Engineering), member of the Romanian Society of Biotechnology, member of the Romanian Association of Applied and Industrial Mathematics (ROMAI), and Associate Editor of IST Transactions (IST Press, Canada). I have published a monograph entitled “Informational Processing of Measuring Data”. Some of my publications (about 30) have appeared in the journal “International Journal of Computing, Communications, Control”.