The modern gas turbine is a complex machine, the design and development of which takes many months and costs Millions. The European gas turbine manufacturing industry is under pressure to minimise the resources required to bring a new design to market, due to global competitive pressure and increasing customer expectations.
Accurate design and prediction tools are keys to success in this process. The PREMECCY project identifies the field of rotor blade Combined Cycle Fatigue (CCF) as an area where there are shortcomings in the existing industry standard design and prediction tools and thus where significant benefits can be achieved. Rotor blade CCF accounts for up to 40% of the total number of issues that arise during an engine development programme and a similar proportion of in-service problems.
The primary objective of the PREMECCY project was to develop new and improved CCF prediction methods for use in the design process. These would halve the number of development and in-service CCF problems thereby reducing the time and cost required to develop a new engine and reducing the operating costs once in service. They would also enable the design of lighter, more efficient blades, reducing engine sfc.
The fundamental aim of the PREMECCY project was to deliver new and improved Combined Cycle Fatigue prediction tools for use in the industrial design of Gas Turbine blades. This has been performed through a programme of material characterisation and advanced specimen testing that represents a technological step forwards in its own right in conjunction with advanced development of life prediction methods. The project was divided into seven distinct Work Packages (WP), including:
- WP1: Specimen design
- WP2: Specimen procurement
- WP3: Material testing and characterisation on conventional specimens
- WP4: Advanced specimen testing
- WP5: Lifing and predictive methods development
- WP6: Dissemination and exploitation
- WP7: Project management
The PREMECCY project has characterised the behaviour of three gas turbine alloys under Combined Cycle Fatigue loading conditions, which has advanced the knowledge of the material behaviour in operational conditions representative of a gas turbine engine.
The CCF test results of various test series indicate that under certain conditions the HCF fatigue strength can be reduced due to superimposed LCF cycles. The advanced test results generated within PREMECCY provide a good basis to estimate the CCF effect for various materials and test conditions. This will provide an immediate benefit to the industry.
The PREMECCY project has provided industrial partners with access to state of the art methodologies, closer to the physics of the material behaviour and which do show the potentials for future life cycle assessment methods. Promising results can be shown for simple components such as lab specimens, but the application for a real engine component, including validation and certification, is still challenging.
In addition to this, a large number of publications have been developed as part of the PREMECCY project, contributing to the dissemination of the knowledge gained during the project. For detailed information on the results obtained as part of PREMECCY, it is recommended to consult the publications provided in the following section.