Gas turbine combustors employing a single lean combustion stage represent the next generation of design for reduced NO<sub>X</sub>emissions. These lean-burn combustors rely on swirl-stabilised flames resulting in highly non-uniform outflows. Non-uniform conditions adversely affect high-pressure turbine performance. 3D numerical simulations provide a means to understand and optimise engine design, however, the modelling of turbulence means experimental validation is crucial. Turbine test facilities operating at scaled, non-reacting conditions, with simulated combustor flows are an important source of validation data. This thesis presents advances in combustor simulator design, testing and instrumentation relevant to the challenges of modern, highly-integrated turbine testing. The design of a lean-burn combustor simulator, characterised by swirl and non-uniform temperature, is presented. The design was based on measurements and predictions of engine conditions. Unsteady numerical simulations were employed as a predictive design tool. An engine-scale combustor simulator was manufactured and characterised experimentally in a bespoke facility. Surveys of flow structure are presented, focusing on experimental turbine inlet data. These data confirmed that the combustor simulator reproduces the important features of a lean-burn combustor; e.g. swirling mainstream flow and high turbulence intensity. The lean-burn combustor simulator will be the first of its kind to be implemented in a rotating turbine test facility, and will provide important validation data. Measurement techniques were developed alongside the core work. Miniaturised five-hole probe rakes for turbine inlet measurements were developed using additive manufacturing (AM). Building on this work, an open source AM five-hole probe design is presented with experimental validation. The problem of estimating pressure probe bandwidth was also addressed, and a simplified model is presented. These tools have direct applications in turbomachinery research.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:730565 |
| Date | January 2015 |
| Creators | Hall, Benjamin F. |
| Contributors | Povey, Tom |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ora.ox.ac.uk/objects/uuid:9c8e46e6-218f-4715-b2bd-8c8abbee446a |
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