Abradable linings are used within compressors and turbines as they allow blade tip clearances to be minimised, whilst not suffering the penalty of blade tip wear. They are of particular interest in aero-engines, where they help to improve engine efficiency and minimise the consumption of aviation fuel. The nature of the contact between blade tips and abradable materials is not well understood, and in some cases blade wear still occurs. The aim of this project is to investigate this contact, and fundamentally understand the interaction mechanism between these two components.
A laboratory demonstrator platform has been developed, capable of generating the wear conditions observed for abradable linings in an aero-engine compressor. High-speed imaging techniques have been used to investigate the nature of the blade tip contact with the abradable. This technique was able to highlight aspects such as adhesive transfer of abradable material to the blade, and explain the overall wear behaviour of the components. Through this study the drivers behind the propensity for a given wear mechanism have been identified, for both cases with beneficial and detrimental effects on the blade. The outcomes of this work will aid in the design and selection of future abradable materials.
This work is funded by the EPSRC and Rolls-Royce Plc.