On-line monitoring of the carbon deposition in combustion chamber of a turbojet engine

The paper presents the application of the gas path electrostatic monitoring technology for monitoring of carbon deposition in combustion chamber of a turbojet engine. In order to obtain the accurate charge signal, the Least Mean Square (LMS) fitting method is adopted in electrostatic monitoring signal calculus. By the comparison of the data from the 101^st and 13^0th stage, we observer the active level of the signal from the 13^0th stage is significantly higher than that from the 101^st stage, but no evident difference can be detected in the positive (negative) event rate. The change in the active level of the signal can be contributed to the carbon depositions in combustion chamber found in the disassembly of the engine after the 13^0th stage test. So, we can conclude that the electrostatic monitoring system can detect the carbon depositions in the combustion chamber of a turbojet engine.