Display Abstract

Title Equilibria and Their Stability for a Quasi-Stationary Droplet Model

Name Patrick Guidotti
Country USA
Email gpatrick@math.uci.edu
Co-Author(s)
Submit Time 2014-02-13 14:22:27
Session
Special Session 100: Analysis of free boundary problems
Contents
This talk will focus on the stability of the manifold of equilibria for the moving boundary problem $$\begin{cases} -\Delta u=\lambda\, ,&\text{ in }\Omega(t)\text{ for }t>0\,,\\ u=0\, ,&\text{on }\partial\Omega(t)\text{ for }t>0\,,\\ \int _{\Omega(t)}u(x)\, dx=V_0\, ,&\text{for }t>0\\ V=F(|Du|)\, ,&\text{on }\partial\Omega(t)\text{ for }t>0\,,\\ \Omega(0)=\Omega _0\, . \end{cases}$$ satisfied by a viscous droplet sitting on a homogeneous surface and driven by contact angle. The unknown function $u$ describes the height of the droplet, $\Omega(t)$ the wetted region at time $t$, $V_0$ the droplet volume, $V$ the front velocity in direction normal to $\partial\Omega(t)$, and $\lambda$ is a Lagrange multiplier. After the system is recast into a nonlinear nonlocal evolution for the boundary of the moving domain, the analysis proceeds with the explicit computation of the linearization in the equilibria and the introduction of suitable coordinates for $\partial\Omega(t)$ in the space of shapes. In these coordinates the equation takes on a particularly convenient form which simplifies the stability analysis.