Gas Turbine Engines: Compressors

Abstract

Abstract This chapter introduces important basics of the aerodynamics and thermodynamics of compressors. It starts with a classification of all types of compressors, showing various configuration features, operating principles, and applications. The two basic categories, positive displacement compressors and dynamic compressors, are described, followed by a breakdown of sub‐categories: reciprocating, rotary, axial, centrifugal, and diagonal compressors. Advantage and specialty of each type of compressor are explained. Following the discussion on the entire class of compressor family, the chapter then focuses on dynamic compressors only, since dynamic compressors are of primary use in gas turbine engines. The remaining sections of this chapter are dedicated to axial and centrifugal compressors. The aero‐thermodynamic process of a compressor stage is illustrated, using the one‐dimensional mean line approach, explaining how the gas state varies and how the work/energy conversion takes place through the compression. The definition of the compressor efficiency is derived and three commonly used definitions are discussed. The important concepts and terms usually encountered when dealing with compressor research and application are illustrated: surge, stall, choke, performance curve, performance map, operating range, and specific speed. The chapter closes with explaining the complexity, foreseeing the development trend, and providing reference sources of the subject.