Handbook of Turbomachinery Second Edition Revised - Ventech!

aerodynamic design–mechanical design–cooling design (and back to the
cycle analysis) is being recognized as outdated due to boundaries historically
established within each discipline. A significant improvement in the
development process for advanced gas turbine engines can be achieved
through close interaction between various disciplines participating in the
development. This approach often requires compromises within each of the
disciplines to accommodate major interdisciplinary constraints (Fig. 34).
The engine development program starts with a specification of the
application, performance, cost, emission limits, and size/weight targets,
and subsequently progresses through thermodynamic cycle analysis and gaspath
geometry definition. Even at this early stage of development, the
cooling issues play an equally important role with aerodynamic and
structural considerations affecting blade-tip-to-hub-diameter ratio, work
splits between stages, combustor liner surface-to-volume ratio, etc. For a
development program to be successful, a true concurrent engineering
process is essential during these conceptual and preliminary design phases.
Risk-sharing between disciplines, which leads to justifiable safety margins
and is based on probabilistic risk analysis, must replace the traditional more
conservative approach, which is based on overconservative summation of
Figure 34 Factors affecting turbine cooling design.
Copyright © 2003 Marcel Dekker, Inc.