Handbook of Turbomachinery Second Edition Revised - Ventech!

MECHANICAL AND THERMAL DESIGN CONSIDERATIONS
FOR GAS TURBINE ENGINES
Vedanth Kadambi
This section deals with the fundamentals of mechanical and thermal design
of gas turbine engines. It lays particular emphasis on the turbine, though
many of the statements are general and apply to compressor design as well.
Starting from a description of thermodynamic and practical cycles used in
gas turbine applications, it deals with the types of engines and their
applications, the approach to design (including aerodynamic, secondary
flow, thermal and stress analysis), material selection for various applications,
and mechanical design considerations (turbine disk and blade design,
the secondary flow circuit, and prediction of fatigue life). Finally, tests for
design validation and some of the near-term developments that will improve
overall performance and life are discussed.
Mechanical and Thermal Design Considerations—An
Overview
The gas turbine industry is often considered as mature since new large-scale
developments are few and the design process is considered to be well
established. In spite of this, the mechanical/thermal design of a gas turbine is
a highly complex endeavor, costing hundreds of millions of dollars and
employing a team of several hundred engineers for several years. During
design, advances are made through increasing levels of sophistication and
detailed analyses. A full discussion of each of the design topics would easily
fill a volume. A brief presentation will be given here to serve merely as an
overview of the considerations involved in the mechanical design of a
turbine. The topics to be discussed are (1) the gas turbine cycle, engine
components, and the areas of applications of gas turbines, and (2)
performance, material selection, durability, and life. The factors involved
in the aerodynamic, mechanical, and thermal designs, secondary flow, stress
and vibration analyses, life evaluation, etc. will be considered as well. Tests
used to evaluate the performance and durability of the engine conclude the
design phase. A discussion of the directions for future work to improve
performance as well as life will be provided at the end. The reader should
leave the chapter with a global sense of what topics the design engineer must
address. For further details, individual topics should be studied in greater
depth from the cited chapters in this book and literature or from
comprehensive texts on specific topics.
Copyright © 2003 Marcel Dekker, Inc.