Published online by Cambridge University Press: 04 July 2016
For years, the development and testing of aero gas turbines has been hampered by the inability of development and test engineers to perceive and readily measure the positional changes of static and moving components within the engines due to the opaque nature of the engine casing walls. ‘Touch’ or abradable probes have been used but require special engine builds to employ them.
With the introduction of high strength materials and the thinning of engine structures and as the performance requirements have become more demanding, small component movements during engine handling have become more important. This is particularly true in areas where the airflow has the greatest work potential such as the tip and root seals of the high pressure turbine and the root seals of the final compressor stages.