Turbo Machines: Design and Control

With the increase in application of gas turbines in various fields, it is high time to present the
subject matter in a simple and precise manner to furnish the students and practising engineers
the theory and design of gas turbines. This book mainly deals with basic theory of lift and
drag of flying or moving object, velocity diagram analysis of the blades of compressor, blower,
fan and turbines, thermodynamic analysis of gas turbines and control aspects of advanced gas
turbines.
The basic principle of working of turbomachines is the change in energy level of a continuously flowing fluid by the action of a rotating element, i.e., rotor. The theoretical treatment of
such a machine requires the knowledge of both fluid dynamics and thermodynamics. Some
fundamental problems in thermodynamics and fluid dynamics common to gas turbines have
been covered in chapters 1 and 2. Chapter 1 deals with units and dimensional analysis. Model
testing and drill problems are also presented in chapter 1.
Chapter 2 is on compressible fluid flow. Basic equations on gas dynamics, gas flow in nozzle
and ducts and shock waves are presented. A variety of solved problems in SI units are given
to acquaint the students with the problems of compressible fluid flow.
Turbomachines can be analyzed using lift and drag acting on the impeller or the flying object.
Chapter 3 deals with the analysis of flow past immersed body. Flow over plate, cylinder, sphere
and aerofoil are presented analytically and graphically. Kerman vortex is analyzed when the
fluid flows over the immersed body.
Chapter 4 discusses the general classification and analysis of turbomachines. Euler energy
transfer equation for any turbomachine is presented and factors such as degree of reaction,
utilization factor and efficiencies are also presented. The concept of turbomachines analysis is
substantiated with drill problems.
Chapters 5 and 6 present radial flow turbomachines and axial flow turbomachines respectively. Velocity diagram concept is used to analyze the radial flow and axial flow turbomachines which includes compressors and turbines. A number of designing problems give good
understanding of the use of velocity diagram in turbomachine analysis.
Thermodynamics analysis of the turbomachines is important as energy transfer takes place
continuously in these machines. Chapter 7 narrates some basic laws of thermodynamics and
Prefacevi Preface
various cycle analyses of turbomachines using temperature entropy diagram. The drill problems
give analysis of each cycle of the turbomachines which provide a good understanding about the
thermodynamic application in these machines.
Chapter 8 deals with the control strategy in turbomachines. Initially, the speed control of
thermal power plant and gas turbines are illustrated. The control systems used for two-shaft
turbojet engine for aircraft are illustrated with advanced control theory. Multivariable control
system used in modern control theory is applied to two-shaft turbojet engine modeling and
controller design. Chapter 9 includes some of the advanced topics in turbomachines such as
flying birds, fish swinging, etc.
Useful references for further reading are given in the select bibliography at the end of the
book. The material covered in the book will be useful in the study of the subject on steam
and gas turbine, aircraft propulsion, thermal power plant, fluid mechanics and energy studies.
Besides, students, teachers and design engineers in the area of power plant, aerospace, super
charger internal combustion engines, industrial fans and blowers and compressors would also
find this book useful.
Appu Kuttan K.K.