Page 8 - Fluid Mechanics and Thermodynamics of Turbomachinery

Contents vii
Stage loss relationships and efficiency 142
Reaction ratio 143
Choice of reaction 143
Stage loading 144
Simplified off-design performance 145
Stage pressure rise 147
Pressure ratio of a multistage compressor 148
Estimation of compressor stage efficiency 149
Stall and surge phenomena in compressors 154
Control of flow instabilities 159
Axial-flow ducted fans 160
Blade element theory 162
Blade element efficiency 163
Lift coefficient of a fan aerofoil 164
References 165
Problems 166

6. Three-dimensional Flows in Axial Turbomachines 169
Introduction 169
Theory of radial equilibrium 169
The indirect problem 171
The direct problem 179
Compressible flow through a fixed blade row 180
Constant specific mass flow 181
Off-design performance of a stage 183
Free-vortex turbine stage 184
Actuator disc approach 186
Blade row interaction effects 190
Computer-aided methods of solving the through-flow problem 191
Secondary flows 193
References 195
Problems 196
7. Centrifugal Pumps, Fans and Compressors 199

Introduction 199
Some definitions 200
Theoretical analysis of a centrifugal compressor 202
Inlet casing 203
Impeller 203
Conservation of rothalpy 204
Diffuser 205
Inlet velocity limitations 205
Optimum design of a pump inlet 206
Optimum design of a centrifugal compressor inlet 208
Slip factor 213
Head increase of a centrifugal pump 218