In the design of a gas turbine engine it is important to have a good prediction ofthe temperature distribution for components ofthe engine. This research work looks at the method ofpredicting air and metal temperatures of the lIP compressor disc drum. It is a common practice to supply cooling air for the turbine disc and blades by passing the air axially between the bores of adjacent discs in the lIP compressor. Some ofthe central axial throughflow is known to enter the compressor interdisc cavities and a parasitic temperature rise occurs in the throughflow air as a result ofthe convective heat transfer. It is important that the heat transfer mechanism within a compressor interdisc cavity is understood, as the engine designer needs to know the temperature ofthe cooling air and the disc temperatures in order to predict the stress and the life of the compressor, and also to predict the seal and blade tip running clearances.In this thesis, computational fluid dynamics (CFD) is used to study the flow and heat mechanism experienced by a gas turbine lIP compressor rotor. A review ofprevious research work and knowledge in the field of rotational buoyancy-driven flow has shown that the flow within the compressor inter-disc cavities is highly three-dimensional and time dependent in nature. Two approaches in the numerical modelling ofthe flow can be considered; one is to use CFD as a tool to model a single inter-disc cavity with axial throughflow in full three dimensions with unsteady flow. Using this approach requires a huge amount ofcomputational memory and time to run the CFD models. A second approach is to break down this complex flow process into separate physical mechanisms and introduce approximate but computationally efficient models for these processes. The second approach has been taken in this thesis, with the aim ofproducing a method that can be incorporated into current design practice. Two underlying flow mechanisms may be identified for this complex flow; the first associated with the flow within the inter-disc cavities and the second associated with the axial throughflow under the compressor disc bores.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:486165 |
| Date | January 2008 |
| Creators | Kilfoil, Alistair S. R. |
| Publisher | University of Surrey |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://epubs.surrey.ac.uk/1028/ |
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