Piston Scuffing Detection by Acoustic Emission Method

The piston scuffing is a major failure of an internal combustion engine. This failure occurs due to loss of the oil film between the piston and the cylinder liner. The piston scuffing investigation by the acoustic emission (AE) method is a new study. Because this failure occurs randomly، it is an online detection which is very difficult. The goal of this paper is to study the ability of the AE method to be applied to the piston scuff detection. In addition record of the AE signal behaviour، before and after the piston scuffing is another new purpose. To this order، in an experimental set-up، two AE sensors was installed on the cylinder head and the engine block of a diesel engine. We know that the blow-by is directly affected by the piston scuffing failure. Therefore، it was measured as a base parameter. The creation of intended piston scuff conditions is very difficult. Therefore، a special test was designed to make it artificially. Results show that the best AE parameter for the piston scuff detection is the AE root mean square and the AE energy. Based on the present method، we can find the location of the event in the cylinder head or in the engine block.