Helping Rolls-Royce plc improve jet engine efficiency

Our research has enabled Rolls-Royce plc to better predict the performance of the thermal barrier coatings on their jet engine components. The coatings have helped boost engine performance and reduce fuel consumption.

Addressing the problem with thermal barrier coatings

Thermal barrier coatings (TBCs) enable engine components to operate in demanding thermal and environmental conditions during service operation. Improved TBCs, and the protection they offer, allows engines to run hotter and more efficiently. Determining the long-term performance of new TBCs, especially what can cause them to degrade and fall off, was too complex to predict using standard laboratory tests, but was needed before introducing them into an engine.

An innovative methodology to reduce risk

Materials scientists at Manchester, led by Professor Ping Xiao, developed a stringent methodology of novel testing processes to accurately predict the mechanical, chemical and physical performance of TBCs across the lifetime of a commercial jet engine when subjected to high temperatures and mechanical loads.

They developed tests focused on three key material characteristics:

• multidimensional residual stress;
• the strength of the interface between the TBC coating and the engine parts;
• interfacial adhesion.

Delivering cost and carbon savings

The University's research significantly reduced the risk of Rolls-Royce plc introducing TBCs onto key components of in-service engines. The heightened confidence in the lifelong TBC system performance allowed an increase in engine cycle temperatures, boosting engine performance and reducing specific fuel consumption.

More than 4,000 in-service Rolls-Royce Trent series engines utilise TBC coatings assured by Manchester testing strategies. Since 2013, the Trent series engines have recorded 70 million flight hours. An average 2% fuel saving over 70 million flight hours is equivalent to a saving of 3.6 million tonnes of fuel, worth approximately £1.5 billion in fuel costs and an 11.2-million-tonne reduction in CO₂ emissions.

Rolls-Royce plc is developing next-generation materials for use in gas turbines, where temperatures can reach 2,000°C. The materials used must meet increasingly stringent environmental, performance and fuel efficiency targets while ensuring that Rolls-Royce plc maintains its international competitive advantage.

Professor Ping Xiao’s research helped develop the understanding of the current generation of coating’s performance limits, and the ongoing research will enable the design of next-generation coatings crucial to future aeroplane performance and efficiency levels.