ISBN: 3540666907
TITLE: Optical Measurements
AUTHOR: Mayinger, Feldmann
TOC:

1 Introduction 1
Franz Mayinger and Oliver Feldmann
2 The Schlieren Technique 5
Andreas Eder, Martin Jordan
2.1 Introduction 5
2.2 Basic Principle 5
2.3 Optical and Thermodynamic Interrelations 6
2.3.1 Refraction Index and Temperature Field 7
2.3.2 The Deflection of Light in an Inhomogeneous Medium 7
2.4 Application of the Schlieren Technique 9
2.4.1 Application to Transient Combustion Research 13
The Schlieren Cinematography 13
The Color Schlieren Technique 15
2.4.2 Application to Fuel-Injection Systems 15
3 Fundamentals of Holography and Interferometry 17
Franz Mayinger
3.1 Abstract 17
3.2 Introduction 17
3.3 Principle of Holography 18
3.4 Simple Holographic Arrangement 20
3.5 Holographie Interferometry 24
3.5.1 Double Exposure Technique 24
3.5.2 Real-Time Method 28
3.5.3 Evaluation of the Interferograms 31
3.6 An Interference Method for Simultaneous Heat and Mass Transfer 33
3.7 Comparison with Classical Methods 37
4 Holographic Interferometry 39
Robert Tauscher
4.1 Introduction 39
4.2 Components of a Holographie Interferometer 39
4.2.1 Light Source 39
4.2.2 Optical Table 40
4.2.3 Shutter 41
4.2.4 Beam Splitter 41
4.2.5 Attenuation Filter 41
4.2.6 Beam Expander 41
4.2.7 Mirrors, Lenses 42
4.2.8 Recording Materials 42
4.2.9 Piezo Mirror 43
4.2.10 Test Facility 44
4.3 Evaluation of Interferograms 44
4.3.1 Theoretical Principles 44
4.3.2 Conclusions 49
4.3.3 Calculation of Temperature and Concentration Distributions 49
4.3.4 Determination of the Local Heat Transfer Coefficient 50
4.4 Examples 50
4.4.1 Determination of the Temperature Distribution in a Compact Plate Heat Exchanger with Plain Fins 50
Description of the Test Section 50
Description of the Interferograms 52
5 Short Time Holography 55
Oliver Feldmann, Peter Gebhard, Anselmo Chavez
5.1 Introduction 55
5.1.1 Historical development of holography 55
5.1.2 The holographic image 56

5.1.3 Holography as an Optical measurement method 57
5.2 Elements of holography 58
5.2.1 Recording materials 58
5.2.2 The pulsed laser 61
5.2.3 Optical set-up 62
5.2.4 Adjusting the holographic camera 63
5.2.5 Recording, development and reconstruction of holograms 65
Amplitude hologram 65
Phase hologram 65
5.3 Application example: Dispersion characteristics in stirred bubble columns 66
5.3.1 Statement of the Problem 66
5.3.2 Recording the holograms 68
5.3.3 Reconstruction and evaluation of the holograms 69
5.3.4 Stereo matching of the two holograms 70
5.3.5 Results 71
6 Evaluation of holograms by digital image processing 75
Oliver Feldmann, Robert Tauscher
6.1 Introduction 75
6.1.1 Digitization of a picture 76
6.1.2 Gray value pictures 76
6.1.3 Operations with gray value images 78
6.2 A digital image processing System for the evaluation of holographic
reconstructions 81
6.2.1 Evaluation of holographic images 81
Scanning of in-line holograms 81
Scanning of off-axis holograms 82
6.2.2 Set-up of a digital image processing System 83
6.3 Image processing 83
6.3.1 Evaluation of single pulsed holograms 84
6.3.2 Evaluation of double pulsed holograms 87
6.3.3 Stereo matching algorithm 89
6.3.4 Accuracy 89
6.4 Evaluation of interferograms 90
7 Light Scattering 95
Boris Kruppa, Gernoth Strube, Christof Gerlach
7.1 Introduction 95
7.2 Scattering Processes 97
7.2.1 Interaction of Light and Matter 97
7.2.2 Elastic Scattering 98
7.2.3 Inelastic Scattering 99
7.3 Light Scattering Techniques in Heat Transfer 100
7.3.1 Mie-Scattering 100
7.3.2 Rayleigh-Scattering 103
7.3.3 Raman-Scattering 104
7.3.4 Laser Induced Fluorescence (LIF) 107
7.3.5 Absorption 108
7.4 Concluding Remarks 111
8 Laser-Doppler Velocimetry 113
Andreas Eder, Bodo Durst, Martin Jordan
8.1 Introduction 113
8.2 Principles of LDV 114
8.3 Optics 115
8.4 Signal Processing 117
8.5 Seeding Particles 119
8.6 Determination of Characteristic Turbulence-Quantities 120
8.6.1 Fundamentals of Turbulent Flows 120
8.6.2 Measurement of Turbulence-Quantities 130
9 Phase Doppler Anemometry (PDA) 135
Bernd Ofner
9.1 Introduction 135
9.2 General considerations for the application of PDA 135
9.3 Principles of PDA 136
9.3.1 Light-scattering by particles 136
9.3.2 Optical Parameters of a Phase Doppler Measurement System 138
9.3.3 Phase-diameter relationship 138
9.4 Measurement accuracy 142
9.5 Applications of PDA 143
10 Dynamit Light Scattering 149
Boris Kruppa, Martin Pitschmann, Johannes Straub
10.1 Introduction 149
10.2 Overview 149
10.3 Light Scattering Theory 152
10.3.1 Scattering Geometry and Assumptions 152
10.3.2 Temporal and Spatial Behavior of Scattered Light 154
10.3.3 Correlation Functions 155
10.3.4 Hydrodynamic Fluctuation Theory 160
10.4 Experimental Methods 162
10.4.1 Homodyne Method 162
10.4.2 Heterodyne Method 165
10.5 Measurement of Thermal Diffusivity 166
11 Raman Scattering 169
Gernoth Strube
11.1 Introduction 169
11.2 Theoretical Basics of Raman Spectroscopy 170
11.2.1 Concentration Measurements 173
11.2.2 Temperature Measurement 176
General Considerations 176
Thermometry by Rotational Raman Spectroscopy 178
Thermometry by Vibrational Raman Spectroscopy 181
11.3 Experimental Set-up 184
11.3.1 Laser 186
11.3.2 Focussing and Collection Lenses 187
11.3.3 Spectral Frequency Selection 188
11.3.4 Photon Converters 188
11.3.5 Data Acquisition and Control 189
11.4 Selected Applications 190
11.5 Concluding Remarks 194
12 Laser induced Fluorescence 195
Peter Andresen
12.1 Introduction 195
12.2 Basic Principles of Laser Induced Fluorescence 197
12.2.1 General Considerations 197
12.2.2 Concentration Measurement 203
12.2.3 Temperature Measurement 204
12.2.4 Tracer LIF 206
12.3 Experimental Setup and Procedures 207
12.3.1 Experimental Setup 207
12.3.2 Experimental and Evaluation Procedures 211
12.4 Selected Applications 217
12.5 Concluding Remarks 224
13 Absorption 227
Volker Ebert, Jrgen Wolfrum
13.1 Introduction 227
13.2 Linespectra 228
13.2.1 Position 229
13.2.2 Shape and width 229
A. Natural line broadening 230
B. Doppler broadening 230
C. Collisional broadening 231
D. Voigt function-Mixed line shapes 232
13.2.3 Line strength 234
13.3 Experimental techniques 239
13.3.1 Overview 239
Techniques used in absorption spectroscopy 242
13.3.2 Experimental examples 244
A. In situ measurements of ammonia concentration in industrial combustion systems 244
B. Fast temperature measurements with tunable diode lasers 248
C. Harmonic detection techniques for the measurement of small absorptions 251
D. Simultaneous in-situ detection of Oxygen and water in a full scale waste incinerator with near infrared diode lasers 256
E. In situ determination of free radicals in flames 262
14 Pyrometry and Thermography 266
Udo L. Glckert Robert Schmidt
14.1 Introduction 266
14.2 Temperature Radiation 267
14.3 Method of Transmission 274
14.4 Radiation Receiver (Detector) 276
14.5 Thermal Cameras - Thermography Image Systems 279
14.6 Pyrometers 282
14.6.1 Classification According to Construction Types 285
14.6.2 Filament and Quotient Pyrometers 285
14.6.3 IR Recording Heads 286
14.7 Error Potential 286
14.7.1 Error Sources During Recording 286
14.7.2 Equipment Error 287
14.7.3 Problems with Thermograph Readings 289
14.8 Appendix 290
14.8.1 Important Constants 290
14.8.2 Further Information and Tables 290
15 Tomography 296
Mathias Buchmann, Dieter Mewes
15.1 Introduction 296
15.2 Integral Measurement Methods 299
15.2.1 Absorption Methods 301
15.2.2 Interferometric Methods 301

15.3 Mathematical Reconstruction Methods 303
15.3.1 Algebraic Reconstruction Methods 305
Matrix Methods 305
Iterative Series Expansion 308
15.3.2 Explicit Reconstruction Methods 314
Fourier Transform Method 315
Analytical Solution of Integral Equations 318
15.3.3 Comparison of Reconstruction Methods 320
15.4 Implementations 325
15.4.1 Measurement of temperature fields in stirred vessels 326
15.4.2 Measurement of micro- and macromixing with the tomographical
dualwavelenght tomography 329
15.4.3 Tomographic measurements of flames with the Schlieren effect 332
15.4.4 Chemical species tomography by near infra-red absorption 333
16 Particle Image Velocimetry 336
Wolfgang Merzkirch
16.1 Introduction 336
16.2 Hardware for the experimental set-up 337
16.3 Evaluation Software 341
16.4 Three-dimensional flow 349
16.5 Applications 350
Nomenclature 354
Reference 368
Index 394
END
