Merzkirch Fluid Mechanics of Flow Metering

1. Auflage 2005
ISBN: 978-3-540-26725-6
Verlag: Springer Berlin Heidelberg
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 256 Seiten

Flow meters measure the volumetric flow rate in a pipeline. Most meters are based on deriving a signal from the fluid flow and calibrating the signal against the volumetric flow rate. The calibration is done in fully-developed flow, and the same state of flow must exist at the meter's position when it is in practical use. Because the field of flow metering has been neglected by fluid mechanicists for a long time, this book addresses two major fluid mechanical problems in flow metering: the analysis of signal generation in turbulent pipe flow, which explains the function of the meter beyond a simple calibration, and the possible use of a meter in non-developed flows. These problems are investigated with reference to, and examples from, a variety of meters, e.g. ultrasound cross-correlation meters, vortex meters, and turbine meters. Studying these problems requires consideration of specific phenomena in turbulent non-developed pipe flow, as caused by installations, and finding special solutions with signal processing, both of which are included in the book.

Autoren/Hrsg.

Merzkirch, Wolfgang

Inhaltsverzeichnis

1;Preface;5
2;Contents;7
3;1 Fully Developed Turbulent Pipe Flow;12
3.1;1.1 Basic Equations;12
3.2;1.2 Two-Layer Structure for Ret .8;15
3.3;1.3 Wall Layer;15
3.4;1.4 Core Region;16
3.5;1.5 Friction Law for Given Volume Flux;19
3.6;1.6 Velocity Distribution;20
3.7;1.7 Influence ofWall Roughness;24
3.8;1.8 Low Reynolds Number Pipe Flow;29
3.9;References;31
4;2 Decay of Disturbances in Turbulent Pipe Flow;34
4.1;2.1 Introduction;34
4.2;2.2 Basic Equations;35
4.3;2.3 Fully Developed Pipe Flow;40
4.4;2.4 Eigenvalue Problem;45
4.5;2.5 Comparisons with Experimental Results;53
4.6;References;57
5;3 Optimal Characteristic Parameters for the Disturbances in Turbulent Pipe Flow;60
5.1;3.1 Introduction;60
5.2;3.2 Objective;61
5.3;3.3 Formulae for the Optimal Characteristic Parameters;61
5.4;3.4 Fully Developed Flow;63
5.5;3.5 Minimal Program;64
5.6;3.6 Example;67
5.7;3.7 Experimental Determination of the Characteristic Parameters ( Minimal Program);67
5.8;References;70
6;4 Measurement of Velocity and Turbulence Downstream of Flow Conditioners;72
6.1;4.1 Introduction;72
6.2;4.2 Experiments;73
6.3;4.3 Results and Discussion;76
6.4;4.4 Conclusion;86
6.5;References;88
7;5 Signal Processing of Complex Modulated Ultrasonic Signals;90
7.1;5.1 Introduction;90
7.2;5.2 Cross-Correlation Measurements;91
7.3;5.3 Demodulation by Digital Undersampling;92
7.4;5.4 Digital Hilbert-Transform;94
7.5;5.5 Phase Reconstruction;99
7.6;5.6 Phase Demodulation with Kalman Filter;100
7.7;5.7 Analog Signal Processing;102
7.8;5.8 Conclusion;104
7.9;References;105
8;6 Vortex-Shedding Flow Metering Using Ultrasound;106
8.1;6.1 Introduction;106
8.2;6.2 Physical Background;107
8.3;6.3 Measurement Principle and Test Arrangement;108
8.4;6.4 Simulations;108
8.5;6.5 Comparisons of Pressure and Ultrasonic Signals;109
8.6;6.6 Experiments;110
8.7;6.7 Influence of Disturbances;119
8.8;6.8 Conclusion;120
8.9;References;121
9;7 Ultrasonic Gas-Flow Measurement Using Correlation Methods;122
9.1;7.1 Introduction;122
9.2;7.2 Determination of Traveling Time by Cross-Correlation Functions;124
9.3;7.3 Physical Quantity Measured by Cross-Correlation Functions;125
9.4;7.4 Measurements;127
9.5;7.5 Multipath Arrangement;135
9.6;7.6 Tomographic Reconstruction of Flow Profile;136
9.7;7.7 Conclusion;137
9.8;References;138
10;8 Ultrasound Cross-Correlation Flow Meter: Analysis by System Theory and Influence of Turbulence;140
10.1;8.1 Introduction;140
10.2;8.2 Experiments;142
10.3;8.3 System-Theoretical Model;144
10.4;8.4 Comparison of Theoretical and Experimental Results;152
10.5;8.5 Conclusions;158
10.6;References;158
11;9 Effect of Area Changes in Swirling Flow;160
11.1;9.1 Introduction;161
11.2;9.2 Physical Background;162
11.3;9.3 Mathematical Formulation of the Problem;164
11.4;9.4 Results and Discussion;171
11.5;References;174
12;10 Errors of Turbine Meters Due to Swirl;176
12.1;10.1 Introduction;177
12.2;10.2 Physical and Mathematical Background;179
12.3;10.3 Experiments and Data Reduction;190
12.4;10.4 Discussion;194
12.5;10.5 Conclusions;194
12.6;References;195
13;11 Investigation of Unsteady Three-Dimensional Flow Fields in a Turbine Flow Meter;196
13.1;11.1 Introduction;196
13.2;11.2 Theory of Operation;197
13.3;11.3 Numerical Tools: Fluent and ACHIEVE;199
13.4;11.4 Three-Dimensional Simulations: Geometry and Setup;199
13.5;11.5 Discussion of Results;201
13.6;11.6 The Pressure Shift;207
13.7;11.7 Secondary Flow;209
13.8;11.8 Summary;210
13.9;References;211
14;12 How to Design a New Flow Meter from Scratch;212
14.1;12.1 Introduction;212
14.2;12.2 Measuring Principle;213
14.3;12.3 Setup and Calibration;217
14.4;12.4 Results for Installations;219
14.5;12.5 Conclusions;220
14.6;References;221
15;13 Effects of Disturbed Inflow on Vortex Shedding from a Bluff Body;222
15.1;13.1 Introduction;222
15.2;13.2 Numerical Algorithm;223
15.3;13.3 Results;227
15.4;13.4 Conclusions;232
15.5;References;232
16;14 Correction of the Reading of a Flow Meter in Pipe Flow Disturbed by Installation Effects;234
16.1;14.1 Introduction;234
16.2;14.2 Characterization of the Disturbed Flow;236
16.3;14.3 Experiments;237
16.4;14.4 Relationship Between Error Shift and Flow Disturbance;242
16.5;14.5 Results;243
16.6;14.6 Conclusions;247
16.7;References;248
17;15 How to Correct the Error Shift of an Ultrasonic Flow Meter Downstream of Installations;250
17.1;15.1 Introduction;250
17.2;15.2 Experimental Setup;251
17.3;15.3 Experiments;255
17.4;15.4 Correction;258
17.5;15.5 Results;261
17.6;15.6 Conclusion;263
17.7;References;263
18;Index;266