I am currently working with Dr. Michael
Shearer studying the flow
of
thin
liquid films. We are studying thin films influenced by
surfactant (a surface tension
reducing agent) both on a horizontal
substrate and an inclined plane. Some applications for this research
are surfactant replacement therapy, coating flows, and food science.
The motion of the film is modeled in the lubrication approximation by a
fourth order system of nonlinear PDE. On the inclined plane the film is
driven by both surfactant and gravity. A traveling wave solution
exists for this system which consists of a piecewise constant height
profile and a piecewise linear surfactant profile. We are
examining the stability of this solution both numerically and
analytically. Along with
Daniels' Nonlinear
Lab, we are also considering a film on a horizontal substrate
driven only by surfactant. We are experimentally studying the
location of the surfactant molecules in relation to the movement of the
height of the film. Numerically we model the evolution of the
height of the film with respect to the surfactant concentration. When
physical influences such as gravity, capillarity and surface diffusion
are ignored the system of equations emits a self-similar solution. We
are examining these solutions both numerically and asymptotically.