Among various mechanical devices built to produce power for industrial and societal needs, gas turbines offer a number of significant advantages. The sliding components in reciprocating engines cause considerable vibrations. Hydroelectric power from turbines using water is a great resource, but potential sites are limited. Steam power plants require expensive steam generating equipment of large bulk, and installation may stretch over lengthy time periods. In contrast, gas turbines operate smoothly with low vibrations, are compact in size, can be started rapidly from rest and may be installed fairly quickly. Gas turbines offer even greater benefits in the aviation arena. Turbojet and multi-rotor turbofan engines have no competition for powering larger aircrafts at faster speeds. Applications in other fields abound. An outstanding example is the aeroderivative gas turbines on offshore oil platforms, where their lighter weight, smaller footprint and ability to burn many different types of fuel make it a clear choice. This book is written to meet the needs of students in engineering colleges and practicing engineers. The material has been specifically tailored for college undergraduate and graduate level design engineering of rotating machine courses. In keeping with its mostly introductory nature, the primary focus is on thermodynamic cycle design and practical mechanical design features. Where possible, electronic spreadsheet type of calculations is used in example problems to calculate flow characteristics and related cycle design parameters. The book focuses on: Fuel consumption, power output and exhaust gas emissions State-of-the-art in the thermal and fluid flow technologies for design of single and multi-rotor gas turbines Methods to enhance performance through creative component designs Analysis of complex problems ranging from compressor stall to optimizing operation from partial to full load.