報(bào)
告題目：THE FLUID MECHANICS OF FOAMS
報(bào)告人：Stephen Howard Davis教授 美國西北大學(xué)
時間：2017年9月25日（星期一）10：00-11：00
地點(diǎn)：玉泉校區(qū)教5-333
報(bào)告摘要：
Gasbubbles in a liquid constitutes a two-phase system. When the liquid fraction isvery small, the bubbles crowd each other foaming polyhedral shapes separated bythin liquid films, a foam. Most past studies consider air-water foams ladenwith surfactants that immobilize the interfaces, and allow the foam to formstatic arrays which are studied for preferred shapes using minimum-surface-energy criteria.
In the present talk the dynamics of clean ( surfactant-free ) foams arestudied in two dimensions that lead to disordered evolutions driven by thethinning of the liquid films, the rupture of the films by van der Waalsinstabilities, and the long time fragmentation of the foam. This analysisdepends on the development of networknumerical model from which one can extract statistical relations for the numberof bubbles as a function of time. These results have application the evolutionof metallic foams which if frozen give rise to porous solids having highstrength and low weight useful in the construction of ship, aircraft, androckets.
報(bào)告人簡介：
Prof.Stephen Howard Davis received his Ph.D. in Mathematics from the University ofRensselaer Polytechnic Institute in 1964. He is currently the Walter P. MurphyProfessor of Engineering Sciences and Applied Mathematics, MechanicalEngineering and Chemical and Biological Engineering at Northwestern University.He is a member of National Academy of Sciences, National Academy of Engineeringand American Academy of Arts and Sciences. He was the chief editor of JFM andwas awarded the Fluid Dynamics Prize.
