Algorithm development for acoustic emission measurement in high-frequency ranges and its application on a large two-stroke marine diesel engine

Abstract In this paper, an advance measuring algorithm was designed to measure acoustic emission (AE) signals in a high-frequency range based on a C-Sharp programming language for a large two-stroke marine diesel engine. To verify the ability of this algorithm, an experiment was carried out to investigate the characteristics of the AE signal caused by the combustion process on the large two-stroke low-speed marine diesel engine in the frequency range 100 – 900 kHz. The results showed that the AE signals emitted from the combustion event at around the top dead center could be well-observed in this frequency range. These outcomes also proved that the AE signal could not propagate to other cylinders due to a big distance between the cylinders. However, the combustion process affected the remaining AE sources. Moreover, this technique could be applied to detect the firing state as well as the combustion time of each cylinder.