This thesis presents a rigorous theoretical investigation of the connection between the time asymmetry in the short-time evolution of particle clusters and the intrinsic irreversibility of turbulent flows due to the energy cascade. The theoretical findings are confirmed with data from experiments conducted in a turbulent water flow produced by two counter-rotating propellers. Additionally, it demonstrates experimentally that the addition of minute amounts of polymers to the flow has a significant impact on both two- and four-particle dispersion, altering the energy cascade.
The term turbulence describes a special state of a continuous medium in which many interacting degrees of freedom are excited. One of the interesting phenomena observed in turbulent flows is their time irreversibility. When milk is stirred into coffee, for example, highly complex and interwoven structures are produced, making the mixing process irreversible.
This behavior can be analyzed in more detail by studying the dispersion of particle clusters. Initial experimental and numerical studies on the time asymmetry in two-particle dispersion indicate that particles separate faster backwards than forwards in time, but no conclusive explanation has yet been provided.
- ISBN: 978-3-319-19191-1
- Editorial: Springer
- Encuadernacion: Cartoné
- Fecha Publicación: 09/10/2015
- Nº Volúmenes: 1
- Idioma: Inglés