16:20-17:20
Kumbakonam Rajagopal （Texas A&M University）
講演題目：What are fluids and solids and how do we model them?
Abstract： Concepts such as a fluid and a solid are not as clear and
unequivocal as their usage suggests. After a discussion of why most
definitions that are used, from the most elementary to sophisticated
mathematical definitions based on symmetry groups, are totally inadequate, a
rationale is presented for characterizing “fluid-like” and “solid-like”
behavior. Then, several generalizations of the usual Navier-Stokes model
that forms a cornerstone of fluid mechanics are discussed. Some views of the
pioneers of fluid mechanics that have not been given the attention that they
deserve are presented. It will also be shown that what is viewed as an
elastic body is a very small subset of those bodies that can lay legitimate
claim to being considered as elastic solids. Finally, a general
thermodynamic framework for viscoelastic bodies will be presented.
