Market pressure within the aero industry, and the changing requirement of
airline operators, motivates considerable effort to continuously improve the
design of the modem day gas turbine. Fundamental to the development
programme of a new gas turbine is the monitoring of vibrations of the engine
during its development tests. This entails manual inspection and interpretation
of thousands of diagrams depicting the vibration history observed by several
hundred strain gauge transducers, located on rotating and stationary compressor
This thesis describes an Expert System, developed during a three year research
contract (co-funded by Rolls-Royce and SERC), that has been devised to assist
in the analysis task. Features, depicting various forms of vibration phenomena,
are located on each diagram by image processing techniques and interpreted by
stored engineering knowledge representing the experience of vibration engineers.
Thus, the system is capable of scrutinising vibration data, obtained from engine
tests, and classifying that data as acceptable or in need of further study. The
thesis provides an overall description of the problem of vibration in gas turbines
and describes the image processing techniques and methods of reasoning
employed to interpret the data.
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.