Matt Saxton, Undergraduate Maths Seminar
The dynamic contact angle is the angle between a moving liquid/vapour interface and a solid surface, measured within the liquid at the contact line where the three phases (solid, liquid, gas) meet. There is empirical evidence that the contact angle is related to the velocity of the contact line by a so-called contact line law.
In this talk we will first explain how to derive a very simple model governing the height of an evaporating liquid drop. We will then demonstrate how perturbation theory can be used to derive from this an ODE problem for the contact line law and discuss how to solve this problem numerically. We will also mention some of the applications of this work. The talk should be accessible to everyone and will be of particular interest to anyone who likes fluid dynamics. This material is also relevant to anyone who wears contact lenses!