Advanced Endwall Design in Gas Turbines

Project:

Turbomachinery in both the aviation and industrial power generations sectors is moving toward higher Turbine Entry Temperature (TET). Higher TETs lead to increased efficiency and specific power output of gas turbines; the metal alloys used to build the turbine stages are affected by the higher thermal stresses resulting from increased TETs. In particular, turbine rotor discs are one of the most highly stressed components in the modern engine. An effective way to control the temperature of rotor discs is to purge ‘cold’ flow, bled from the compressor, inside the cavities (generally known as sealing flow). This constitutes what is generally known as a secondary air system. The sealing flow ultimately leaves the disc cavities as ‘egress flow’ and subsequently interacts with the mainstream flow through the vanes and blades. The interaction losses associated with the egress of sealing flow affects the whole performance of the turbine. To minimise loss, designers are tending towards the implementation of non-axisymmetric contours on the endwall at the base of the rotor blades. These endwall contours (EWC) seek to manipulate the local pressure (and velocity) field in order to control the egress.

The proposed PhD project will be conducted within the Turbomachinery Research Centre (TRC) at the University of Bath. The TRC are a world-leading research centre in the field of internal air-systems and seals, specialising in experimental, computational and theoretical modelling of the flow in rotating systems. The use Computational Fluid Dynamic (CFD) simulations is an indispensable tool required to develop new technologies for future generations of gas turbines.

The project will seek to develop state-of-the-art CFD techniques (LES-DES) to investigate the impact of mainstream-purge interaction in a realistic turbine stage. The successful candidate will investigate the role of endwall contours in minimising stage loss. Novel and robust design techniques will be developed, based on optimization processes applied for a range of operating conditions. The proposed design paradigm represents a unique strategy, where endwall and seals are designed in combination.

The student will work in a friendly and multi-disciplinary environment, using a combination of techniques and numerical tools which will further enhance the student’s development. The research will be carried out in close collaboration with Siemens Industrial Turbomachinery Ltd. It is expected that the student will interact closely with other PhD students responsible for the experimental campaigns. The successful candidate will have the opportunity to disseminate the results of the research in international journals and to give presentations at international conferences.


Application:

The successful applicant will ideally have graduated (or be due to graduate) with an undergraduate Masters first class degree and/or MSc distinction (or equivalent). Candidates whose first language is not English should have an IELTS score of 6.5 (minimum 6.0 in each module) or equivalent.

Formal applications should be made via the University of Bath’s online application form for a PhD in Department of Mechanical Engineering. Please ensure that you state the full project title and lead supervisor name on the application form.

https://samis.bath.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RDUME-FP01&code2=0014

Expected start date: January 2020