MSE13: Mathematical modelling of surfactant-reduced engine wear

Background

BP expect significant changes in engine design over the next 10 to 15 years. EU legislation is driving auto manufacturers to create vehicles that operate more efficiently over a standardised test-cycle and therefore emit lower levels of CO₂. Many studies have shown that reducing engine friction could achieve this. While a drop in the viscosity of the lubricant can reduce friction, it may also increase the wear. BP have found that introducing surfactants into their lubricants reduces wear in rig tests by a factor of 10. It is believed that the surfactants adsorb at the surface and that this adsorbed layer is responsible for the improvement in wear characteristics. The surfactant molecules may also have a significant influence on removing the system free bodies which have been broken off from asperities. This removal reduces the wear they cause.

Techniques, Challenges and the Future

We are interested in understanding elastic-hydrodynamical systems in the presence of surfactant molecules. This involves a coupled system of the elastic stress, lubrication theory, and surface chemistry dynamics. Combined, these techniques will help us determine whether surfactant molecules do reduce wear and how they affect the transport of free bodies in the film.