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|Document Type: ||Thesis or dissertation|
|Title: ||Gas Turbine Advanced Performance Simulation|
|Authors: ||Pachidis, Vassilios|
|Supervisors: ||Pilidis, Pericles|
|Issue Date: ||Jan-2006|
|Abstract: ||Current commercial `state of the art' engine simulation software is of a low fidelity.
Individual component performance characteristics are typically represented via nondimensional
maps with empirical adjustments for off-design effects. Component nondimensional
characteristics are usually obtained through the averaging of
experimental readings from rig test analyses carried out under nominal operating
In those cases where actual component characteristics are not available and default
maps are used instead, conventional simulation tools can offer a good prediction of
the performance of the whole engine close to design point, but can deviate
substantially at of design and transient conditions. On the other hand, even when real
component characteristics are available, zero-dimensional engine cycle simulation
tools can not predict the performance of the engine at other than nominal conditions
satisfactorily. Low-fidelity simulation tools are generally incapable of analyzing the
performance of individual engine components in detail, or capturing complex physical
phenomena such as inlet flow distortion.
Although the available computational power has increased exponentially over the last
two decades, a detailed, three-dimensional analysis of an entire propulsion system still
seems to be so complex and computationally intensive as to remain cost-prohibitive.
For this reason, alternative methods of integrating different types and levels of
analysis are necessary. The integration of simulation codes that model at different
levels of fidelity into a single simulation provides the opportunity to reduce the
overall computing resource needed, while retaining the desired level of analysis in
specific engine components.
The objective of this work was to investigate different simulation strategies for
communicating the performance characteristics of an isolated gas turbine engine
component, resolved from a detailed, high-fidelity analysis, to an engine system
analysis carried out at a lower level of resolution. This would allow component-level,
complex physical processes to be captured and analyzed in the context of the whole
engine performance, at an affordable computing resource and time.
More specifically, this work identified and thoroughly investigated several advanced
simulation strategies in terms of their actual implementation and potential, by looking
into relative changes in engine performance after integrating into the basic, nondimensional
cycle analysis, the performance characteristics of i) two-dimensional
Streamline Curvature (SLC) and ii) three-dimensional Computational Fluid Dynamics
(CFD), engine component models.
In the context of this work, several case studies were carried out, utilising different
two-dimensional and three-dimensional component geometries, under different
operating conditions, such as different types and extents of compressor inlet pressure
distortion and turbine inlet temperature distortion. More importantly, this research
effort established the necessary methodology and technology required for a full, twodimensional
engine cycle analysis at an affordable computational resource.|
|Appears in Collections:||PhD and Masters by research theses (School of Engineering)|
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