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(ProQuest: ... denotes formulae and/or non-US-ASCII text omitted; see image)
[...]
level of significance
[...]
regression coefficient
C
constant
CR
cruise
FEA
Finite Element Analysis
FEM
finite Element Model
H
height (TH and SS parameters)
HPT
high-Pressure Turbine
HTCs
heat Transfer Coefficients
MDO
multi-Disciplinary Optimisation
n
sample size
PMDO
preliminary MDO
PTO
potential To Oversimplify
SFC
Specific Fuel Consumption
SS
shroud Segment
TO
take-Off
TH
turbine housing
R
radius (TH and SS parameters)
R2
coefficient o determination
W
width (TH and SS parameters)
1.0
INTRODUCTION
The gas turbine industry has evolved over the past two decades, characterised by an increase in computer performance and advanced analytical tools. These tools reduced drastically the time required to design a gas turbine. Therefore, in the search for an optimal solution for better engine performances, the number of design iterations increased with an acceptable overall design time. To reach an optimal design process, the complex task of gas turbine design was divided into multiple sub-tasks called disciplines. Then, a trade-off between the disciplines' requirements was made. This methodology can be referred to as Multi-Disciplinary Optimisation (MDO). The gas turbine design was also divided in two phases: the preliminary phase and the detail design phase. At the detail design phase, efficient interactions between each discipline tool are crucial and it is extremely challenging to make significant changes to the design. To overcome this difficulty, the use of MDO at the preliminary design phase (Preliminary MDO or PMDO) allows making more design iterations where there is more freedom to make modifications(1,2). PMDO should shorten time for the preliminary design and improve the quality of the results. To implement PMDO, a project with Pratt & Whitney Canada was undertaken to create a set of preliminary design tools focusing on turbine components i.e. rotor, Turbine Housing (TH) and Shroud Segment (SS). Implementation of PMDO generally includes four steps: parameterisation of geometric and performance parameters, development or improvement of correlations, integration of disciplines and components and finally optimisation. The present work focuses on the first two steps with also some integration.
Two key characteristics in an optimum TH and SS design are the calculation of the tip clearance and the SS cooling flow in the High-Pressure Turbines (HPT)....