This book begins with a review of basic thermodynamics and fluid mechanics principles to motive their application to aerothermodynamics and real-life design issues. The approach is ideal for the reader who will face practical situations and design decisions in the gas turbine industry. Among its features are an emphasis on the role of entropy in assessing machine performance, a timely review of flow structures, revisiting the subsonic and supersonic De Laval nozzle as it applies to bladed turbomachinery components, and an applied review of boundary layer principles. The book highlights the importance of invariant properties across a turbomachinery component in carrying out real computational tasks.