Fluid Mechanics and Thermodynamics of
Pages : 536
Size : 11 MB
This book was originally conceived as a text for students in their final year reading for an honors
degree in engineering that included turbomachinery as a main subject. It was also found to be a
useful support for students embarking on postgraduate courses at masters level. The book was written
for engineers rather than for mathematicians, although some knowledge of mathematics will
prove most useful. Also, it is assumed from the start that readers will have completed preliminary
courses in fluid mechanics. The stress is placed on the actual physics of the flows and the use of
specialized mathematical methods is kept to a minimum.
Compared to the sixth edition, this new edition has had a large number of changes made in
terms of presentation of ideas, new material, and additional examples. In Chapter 1, following the
definition of a turbomachine, the fundamental laws of flow continuity, the energy and entropy
equations are introduced as well as the all-important Euler work equation. In addition, the proper-
ties of working fluids other than perfect gases are covered and a steam chart is included in the
appendices. In Chapter 2, the main emphasis is given to the application of the “similarity laws,” to
dimensional analysis of all types of turbomachine and their performance characteristics. Additional
types of turbomachine are considered and examples of high-speed characteristics are presented.
The important ideas of specific speed and specific diameter emerge from these concepts and their
application is illustrated in the Cordier Diagram, which shows how to select the machine that will
give the highest efficiency for a given duty. Also, in this chapter the basics of cavitation are exam-
ined for pumps and hydraulic turbines.
The measurement and understanding of cascade aerodynamics is the basis of modern axial tur-
bomachine design and analysis. In Chapter 3, the subject of cascade aerodynamics is presented in
preparation for the following chapters on axial turbines and compressors. This chapter was
completely reorganized in the previous edition. In this edition, further emphasis is given to com-
pressible flow and on understanding the physics that constrain the design of turbomachine blades
and determine cascade performance. In addition, a completely new section on computational meth-
ods for cascade design and analysis has been added, which presents the details of different numeri-
cal approaches and their capabilities.
Chapters 4 and 5 cover axial turbines and axial compressors, respectively. In Chapter 4, new
material has been added to give better coverage of steam turbines. Sections explaining the numer-
ous sources of loss within a turbine have been added and the relationships between loss and effi-
ciency are further detailed. The examples and end-of-chapter problems have also been updated.
Within this chapter, the merits of different styles of turbine design are considered including the
implications for mechanical design such as centrifugal stress levels and cooling in high-speed and
high temperature turbines. Through the use of some relatively simple correlations, the trends in tur-
bine efficiency with the main turbine parameters are presented.
In Chapter 5, the analysis and preliminary design of all types of axial compressors are covered.
Several new figures, examples, and end-of-chapter problems have been added. There is new cover-
age of compressor loss sources and, in particular, shock wave losses within high-speed rotors are
explored in detail. New material on off-design operation and stage matching in multistage compres-
sors has been added, which enables the performance of large compressors to be quantified.