Modelling Creep-Fatigue Damage and Life Prediction for Gas Turbine Rotors

About the Project
The current market conditions are such that combined cycle gas turbine (CCGT) plants are now considering double two-shift operation, so potentially accruing upwards of 600 starts per year. This increased thermal cycling has a detrimental effect on component life. One critical component is the gas turbine rotor. The ability to accurately calculate the remaining life of the rotors through prediction of creep and fatigue damage will enable reduction of financial and environmental costs associated with premature replacement. Ultimately these cost reductions could benefit the consumer and the economy.

RWE Generation operates gas (CCGT), biofuel and coal power stations across Europe. It is one of the largest electricity generation companies within Europe. Since its power station components operate at high temperatures and pressures, RWE has technical interest in component life prediction and extension through modelling, plant performance optimisation, metallurgy, welding and new materials.

A previous research programme, conducted over the last 3 years at Nottingham, has involved development of a visco-plastic material model for one of the rotor steels, determination of the material model parameters through experimental testing and development of a finite element model of the rotor with some limited life prediction capability.

The aim of the current project is to continue this research to fully develop a model which can provide accurate life predictions for the rotor given the correct thermal boundary conditions.

Specific objectives will include:
1. Further development of a 3D finite element model of the rotor including all potential high damage regions (e.g. including blade root to rotor contact).
2. Refinement of the visco-plastic model to better simulate creep-fatigue interaction during turbine start up and shut down.
3. Extension of the visco-plastic model to include damage/life prediction.
4. Material testing to provide model parameters for the second rotor material.

High temperature mechanical testing and physical characterization will be carried out using well-established facility. The theoretical and modelling work will be carried out using finite element package ABAQUS through user defined subroutines.

We are seeking applicants to start in September 2020.

Candidates should have a first or high 2.1 class honours degree in an engineering or science discipline (e.g. mechanical engineering, applied mechanics or applied mathematics). A strong background of Mechanics of Solids, Mathematics and Computational Modelling is preferable.

The scholarship on offer (to eligible students) comprises a tax-free stipend of £15,009 (2020/2021) a year for four years, and paid UK/EU tuition fees. Due to funding restrictions, this position is only available for UK or EU candidates.

This project will be partly funded by RWE UK. The student will have opportunity to work with RWE experts. The Industrial Supervisor is Dr Jeremy Hughes at RWE UK.

The PhD student will work within the EPSRC Centre for Doctor Training (CDT) “Resilient decarbonised Fuel Energy Systems”.

Informal enquiries may be sent to Prof Wei Sun ([email protected]). Please note that applications sent directly to this email address will not be accepted.