Neil Balmforth

University of British Columbia

Impacts of a yield stress fluid

Fluids and Materials Seminar

30th May 2024, 2:00 pm – 3:00 pm
Fry Building, Fry 2.04

A favourite Italian dessert is the Panna Cotta, similar to thick custard or blancmange. It resists the force of gravity, to stand up in the shape in which it was set, but when a spoon is pushed in, panna cotta fluidly flows apart along a seam. The material therefore combines the properties of a solid with those of a viscous fluid, depending on the strength of the imposed stress. In other words, panna cotta has properties one usually associates with a yield-stress fluid. Although we now have a good understanding of low-Reynolds number hydrodynamics, and elegant techniques to dissect it, one cannot truly say the same for yield-stress fluids. Accordingly, in this talk, I will discuss the impact of a yield stress in the relatively simple setting of two-dimensional, steady, inertia-less flow. The main goal is to establish intuition for the dramatically different features that can be introduced by the yield stress.

Comments are closed.