Fluid*DTU seminar by
Masao Doi
Beihang University
Beijing
Onsager principle in soft matter
Abstract:
According to the Stokes equation in hydrodynamics, the velocities of particles moving in a viscous fluid are written as linear combinations of the driving forces exerted on the particles, and the coefficients form a symmetric matrix, i.e., the coefficients satisfy the reciprocal relation. Onsager noticed that many kinetic equations in irreversible thermodynamics are written in the same form, and showed that the reciprocal relation is generally guaranteed in such equations. The reciprocal relation allows us to state the kinetic equation in terms of a variational principle. Here I will show that this principle (which I call Onsager principle) gives us a very convenient framework in the study of soft matter. (1) Diffusion of sedimentation of colloidal systems, (2) gel dynamics and nemato-hydrodynamics etc.