Inhalt des Dokuments
Fokker-Planck Equation approach to the orientational dynamics in complex fluids
Lecture course in winter / summer - semester 2012
Lecturer:
Prof. Dr. Siegfried Hess
Period:
March 12 - 14, 2012
Day, time, and place
The lectures take place in room EW 731, TU Berlin, at the following dates
Monday, March 12, 14-16 h
Tuesday, March 13, 10-12 h and 14-16 h
Wednesday, March 14, 10-12 h.
Abstract
The orientation of rod-like or disc-like particles in molecular fluids, polymeric liquids or liquid cristals
is described by an orientational distribution function, whose time dependence is governed by a
generalised Fokker-Planck equation. The basic physics underlying the dynamics is discussed.
Special attention is paid to relaxation and to the coupling of orientation with the flow processes.
The most relevant moment of the orientational distribution is the second rank alignment tensor,
often referred to as Q-tensor. An equation for the time-change of the alignment tensor is derived
from the Fokker-Planck equation. In this way, directly measurable relaxation-time and transport
coefficients are related to coefficients quantifying the torques acting on the non-spherical particles.
Finally some applications are presented.