Boselli, P;
(2016)
An inverse design methodology for long last-stage steam turbine blades.
Doctoral thesis , UCL (University College London).
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Abstract
The last stage of an axial steam turbine is characterized by transonic flow and high volume flow rates. The resulting turbine blades are very large in size and complex in shape. This poses great design challenges, which last-stage blades are infamous for amongst steam turbine designers. Additionally, two-phase flows of condensing steam are always the case, and accurate numerical predictions of performance become often arduous. Inverse design has been used for several years and with great success in a variety of turbomachinery applications. However, no specific inverse design strategy has been developed for large axial steam turbines, and last-stage blades in particular. The first requirement that comes to mind for a steam-turbine specific inverse method is the inclusion of two-phase e↵ects. However, several other problems arise when dealing with the geometries typical of the last stage. The aim of this project is to identify and analyse the problems and requirements, and then develop some specific solutions which will allow the creation of a dedicated inverse design procedure. The first part of the project deals with a traditional inverse method and the inclusion of two-phase effects. The problems are then highlighted and two attempts are made to create a methodology that would work for last-stage blades. After devising a new way of describing blade profiles, the first method is introduced, based on a transpiration model. The second method is circulation based, and works through the prescription of circumferentially averaged swirl velocity. Finally, a design strategy is suggested for the whole redesign of a last stage rotor.
Type: | Thesis (Doctoral) |
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Title: | An inverse design methodology for long last-stage steam turbine blades |
Event: | UCL (University College London) |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
UCL classification: | UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
URI: | https://discovery.ucl.ac.uk/id/eprint/1508258 |
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