Modeling of piston ring wear

A theoretical study of piston ring wear in large two-stroke engines is presented. Piston rings in combustion engines are manufactured with an initially defined shape of the surface contacting the cylinder liner. Further the ring surface working against the cylinder liner is coated with layers of ceramic materials to accommodate the running-in process. Most rings have a nonflat shape (parabolic) when delivered from the ring supplier. After running in which is typically many hours of operation( >1000 h) the ceramic layers are worn and the ring geometry is typically changed significantly by surface wear. It is shown in the present study that the geometry of the worn ring depends on the operation scheme of the engine. Both the load pattern and the order in which the loads are applied influences the final shape of the piston ring surface.