xx
Contents
3.8.9 Inlet Guide Vane with a Centrifugal Fan .............................. 149
3.8.10 Change of Rotational Speed with Centrifugal and
Axial Fans ............................................................................ 149
3.8.11 Two-Stage Axial Fan ............................................................ 150
3.8.12 Axial Turbine ........................................................................ 151
References ................................................................................................. 151
4 Compressible Fluids ................................................................................ 153
4.1 Basic Laws ....................................................................................... 153
4.2 Compressibility and Velocity of Sound ............................................ 156
4.3 Compressibility Effect on the Velocity-Pressure Relation ............... 158
4.4 Shape of a Nozzle ............................................................................. 160
4.5 Nozzle with Initial Velocity .............................................................. 162
4.6 Nozzle with Losses: Infinitesimal Efficiency .................................. 163
4.7 Isentropic and Polytropic Efficiencies ............................................. 167
4.8 Exercises .......................................................................................... 171
References ................................................................................................. 174
5 Performance Measurement .................................................................... 175
5.1 Pressure Measurement ..................................................................... 175
5.1.1 The Metal Manometer .......................................................... 175
5.1.2 The Pressure Transducer ...................................................... 175
5.1.3 The Digital Manometer ........................................................ 176
5.1.4 Calibration of Pressure Meters ............................................. 177
5.2 Temperature Measurement ............................................................... 177
5.2.1 The Glass Thermometer ....................................................... 177
5.2.2 The Temperature Transducer ................................................ 177
5.2.3 The Digital Thermometer ..................................................... 178
5.3 Flow Rate Measurement .................................................................. 178
5.3.1 Reservoir .............................................................................. 178
5.3.2 Flow Over a Weir ................................................................. 178
5.3.3 Pressure Drop Devices ......................................................... 179
5.3.4 Industrial Mass Flow Rate Meters ....................................... 180
5.3.5 Positioning of Flow Rate Meters in Ducts ........................... 180
5.4 Torque Measurement ........................................................................ 181
5.4.1 Swinging Suspended Motor or Brake .................................. 181
5.4.2 Calibrated Motor .................................................................. 181
5.4.3 The Torque Transducer ......................................................... 181
5.5 Rotational Speed Measurement ........................................................ 182
5.5.1 Pulse Counters ...................................................................... 182
5.5.2 The Speed Transducer .......................................................... 182
5.5.3 Electric Tachometer .............................................................. 182
5.6 Laboratory Test of a Pelton Turbine ................................................. 182
5.6.1 Test Rig ................................................................................ 182
5.6.2 Measurements ...................................................................... 183
Contents
3.8.9 Inlet Guide Vane with a Centrifugal Fan .............................. 149
3.8.10 Change of Rotational Speed with Centrifugal and
Axial Fans ............................................................................ 149
3.8.11 Two-Stage Axial Fan ............................................................ 150
3.8.12 Axial Turbine ........................................................................ 151
References ................................................................................................. 151
4 Compressible Fluids ................................................................................ 153
4.1 Basic Laws ....................................................................................... 153
4.2 Compressibility and Velocity of Sound ............................................ 156
4.3 Compressibility Effect on the Velocity-Pressure Relation ............... 158
4.4 Shape of a Nozzle ............................................................................. 160
4.5 Nozzle with Initial Velocity .............................................................. 162
4.6 Nozzle with Losses: Infinitesimal Efficiency .................................. 163
4.7 Isentropic and Polytropic Efficiencies ............................................. 167
4.8 Exercises .......................................................................................... 171
References ................................................................................................. 174
5 Performance Measurement .................................................................... 175
5.1 Pressure Measurement ..................................................................... 175
5.1.1 The Metal Manometer .......................................................... 175
5.1.2 The Pressure Transducer ...................................................... 175
5.1.3 The Digital Manometer ........................................................ 176
5.1.4 Calibration of Pressure Meters ............................................. 177
5.2 Temperature Measurement ............................................................... 177
5.2.1 The Glass Thermometer ....................................................... 177
5.2.2 The Temperature Transducer ................................................ 177
5.2.3 The Digital Thermometer ..................................................... 178
5.3 Flow Rate Measurement .................................................................. 178
5.3.1 Reservoir .............................................................................. 178
5.3.2 Flow Over a Weir ................................................................. 178
5.3.3 Pressure Drop Devices ......................................................... 179
5.3.4 Industrial Mass Flow Rate Meters ....................................... 180
5.3.5 Positioning of Flow Rate Meters in Ducts ........................... 180
5.4 Torque Measurement ........................................................................ 181
5.4.1 Swinging Suspended Motor or Brake .................................. 181
5.4.2 Calibrated Motor .................................................................. 181
5.4.3 The Torque Transducer ......................................................... 181
5.5 Rotational Speed Measurement ........................................................ 182
5.5.1 Pulse Counters ...................................................................... 182
5.5.2 The Speed Transducer .......................................................... 182
5.5.3 Electric Tachometer .............................................................. 182
5.6 Laboratory Test of a Pelton Turbine ................................................. 182
5.6.1 Test Rig ................................................................................ 182
5.6.2 Measurements ...................................................................... 183