This text outlines the fluid and thermodynamic principles that apply to all classes of turbomachines, and the material has been presented in a unified way. The approach has been used with successive groups of final year mechanical engineering students, who have helped with the development of the ideas outlined. As with these students, the reader is assumed to have a basic understanding of fluid mechanics and thermodynamics. However, the early chapters combine the relevant material with some new concepts, and provide basic reading references. Two related objectives have defined the scope of the treatment. The first is to provide a general treatment of the common forms of turbo machine, covering basic fluid dynamics and thermodynamics of flow through passages and over surfaces, with a brief derivation of the fundamental governing equations. The second objective is to apply this material to the various machines in enough detail to allow the major design and performance factors to be appreciated. Both objectives have been met by grouping the machines by flow path rather than by application, thus allowing an appreciation of points of similarity or difference in approach. No attempt has been made to cover detailed points of design or stressing, though the cited references and the body of information from which they have been taken give this sort of information. The first four chapters introduce the fundamental relations, and the suc­ ceeding chapters deal with applications to the various flow paths.

1 Fundamental principles.- 1.1 Introduction.- 1.2 Euler equation.- 1.3 Reaction.- 1.4 Application to a centrifugal machine.- 1.5 Application to axial pumps and turbines.- 1.5.1 Axial pump or fan.- 1.5.2 Axial turbine stage.- 1.6 Alternative operating modes.- 1.7 Compressible flow theory.- 1.7.1 General application to a machine.- 1.7.2 Compression process.- 1.7.3 Expansion process.- 1.8 Shock wave effects.- 1.9 Cavitation.- 1.9.1 Phenomenon of cavitation.- 1.9.2 Suction pressure and NPSH (or NPSE).- 1.10 Illustrative examples.- 1.10.1 Radial outflow machine (pump).- 1.10.2 Axial pump and turbine.- 1.10.3 Compressible flow problem.- 1.10.4 Example of an NPSE calculation.- 2 Principles and practice of scaling laws.- 2.1 Introduction.- 2.2 Performance laws.- 2.3 Concept of specific speed.- 2.4 Cavitation parameters.- 2.5 Scale effects in incompressible units.- 2.5.1 Hydraulic machines.- 2.5.2 Cavitation problems.- 2.5.3 Fans and blowers.- 2.6 Scale effects in compressible machines.- 2.7 Illustrative examples.- 2.7.1 Similarity laws applied to a water turbine.- 2.7.2 Compressor performance prediction problem.- 3 Principles of axial flow machines.- 3.1 Introduction.- 3.2 Wing theory.- 3.3 Isolated aerofoil data.- 3.4 Cascade data.- 3.5 Radial equilibrium theories.- 3.6 Actuator disc approach.- 3.7 Stall and surge effects.- 3.7.1 Introduction.- 3.7.2 Stalling of fans and compressor stages.- 3.7.3 Surge and stall in compressors.- 4 Principles of radial and mixed flow machines.- 4.1 Introduction.- 4.2 One-dimensional approach.- 4.3 Two-dimensional approach.- 4.3.1 Passage shapes.- 4.3.2 Impeller or rotating cascade.- 4.4 Three-dimensional problem.- 4.5 Discussion of theoretical approaches to analysis and design.- 5 Centrifugal machines.- 5.1 Introduction.- 5.2 Inlet or intake systems.- 5.3 Impeller.- 5.3.1 Eye or inducer section.- 5.3.2 Impeller design.- 5.4 Outlet systems.- 5.4.1 Vaneless diffuser.- 5.4.2 Volute or spiral casing.- 5.4.3 Vaned diffuser systems.- 5.5 Thrust loads due to hydrodynamic effects.- 5.5.1 Radial thrust forces.- 5.5.2 Axial thrust loads.- 6 Axial machines for incompressible flow.- 6.1 Introduction.- 6.2 Axial flow pumps and fans.- 6.3 Axial water turbines.- 6.4 Forces on blades and their implications for design.- 6.4.1 Static blades.- 6.4.2 Rotating blades.- 6.5 Concluding remarks.- 7 Axial turbines and compressors for compressible flow.- 7.1 Introduction.- 7.2 Approach to axial compressor principles.- 7.3 Axial turbine principles.- 7.3.1 General principles.- 7.3.2 Partial admission problem.- 7.4 Other problems.- 8 Radial flow turbines.- 8.1 Introduction.- 8.2 Water turbines.- 8.3 Radial inflow gas turbine.- 8.3.1 Nozzle systems.- 8.3.2 Rotor geometry.- 8.3.3 Worked example.- 8.4 Ljungström or radial outflow turbine.- 9 Cavitation and other matters.- 9.1 Introduction.- 9.2 Effects of cavitation on machines.- 9.2.1 Surface damage and erosion effects.- 9.2.2 Hydrodynamic effects.- 9.2.3 Thermodynamic effects on pump cavitation.- 9.2.4 Inducer.- 9.3 Problems involved in special pumping applications.- 9.3.1 Gas suspension problems.- 9.3.2 Solids pumping.- 9.3.3 Pumping viscous fluids.- 9.4 Pumped storage systems.- 9.5 Some comments on output control of rotating machines.- References.- Additional bibliography.