Nonlinear electrified viscous free-surface flows over topography

Project Details


We will study how an electric field can influence the shape and behaviour of one or more liquids flowing with a free surface. A free surface divides one fluid from another. For example, a free surface arises at the boundary of a jet of water and separates the water from the air. Free surface flows occur in a wide variety of technological
processes in industry. Examples include the coating of photographic plates and the manufacture of microelectronic devices. A liquid film may also be used as a means of cooling. Often the surface over which the film is flowing is uneven and this can have an important effect on the shape of the free surface. For example, a liquid film flowing over
a downward step exhibits a clearly-defined ridge just above the step. This may be an undesirable feature if one is seeking a smooth flat coating.

We will investigate how an electric field might be used to influence such a ridge. The electric field affects the fluid flow by modifying the stresses experienced by the liquid at the free surface. By varying the intensity of the electric field, we can, to some extent, control these stresses and thereby control the film flow. We will conduct a general study of the flow of liquid films over rough surfaces and examine how the wall roughness affects the free surface shape and to what extent this can be controlled by an electric field. We will also study the effect of electric fields in many other contexts, including the flow of two superposed viscous fluids, and the birth of liquid drops.
Effective start/end date15/08/0614/08/08


  • Engineering and Physical Sciences Research Council: £101,191.00