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Increasing possibilities of computer-aided data processing have caused a new revival of optical techniques in many areas of mechanical and chemical engi neering. Optical methods have a long tradition in heat and mass transfer and in fluid dynamics. Global experimental information is not sufficient for de veloping constitution equations to describe complicated phenomena in fluid dynamics or in transfer processes by a computer program. Furthermore, a detailed insight with high local and temporal resolution into the thermo and fluiddynamic situations is necessary. Sets of equations for computer program in thermo dynamics and fluid dynamics usually consist of two types of formulations: a first one derived from the conservation laws for mass, energy and momentum, and a second one mathematically modelling transport processes like laminar or turbulent diffusion. For reliably predicting the heat transfer, for example, the velocity and temperature field in the boundary layer must be known, or a physically realistic and widely valid correlation describing the turbulence must be avail able. For a better understanding of combustion processes it is necessary to know the local concentration and temperature just ahead of the flame and in the ignition zone.
Sommario
1 Introduction.- 2 The Schlieren Technique.- 2.1 Introduction.- 2.2 Basic Principle.- 2.3 Optical and Thermodynamic Interrelations.- 2.4 Application of the Schlieren Technique.- 3 Fundamentals of Holography and Interferometry.- 3.1 Abstract.- 3.2 Introduction.- 3.3 Principle of Holography.- 3.4 Simple Holographic Arrangement.- 3.5 Holographic Interferometry.- 3.6 An Interference Method for Simultaneous Heat and Mass Transfer.- 3.7 Comparison with Classical Methods.- 4 Holographic Interferometry.- 4.1 Introduction.- 4.2 Components of a Holographic Interferometer.- 4.3 Evaluation of Interferograms.- 4.4 Examples.- 5 Short Time Holography.- 5.1 Introduction.- 5.2 Elements of holography.- 5.3 Application example: Dispersion characteristics in stirred bubble columns.- 6 Evaluation of holograms by digital image processing.- 6.1 Introduction.- 6.2 A digital image processing system for the evaluation of holographic reconstructions.- 6.3 Image processing.- 6.4 Evaluation of interferograms.- 7 Light Scattering.- 7.1 Introduction.- 7.2 Scattering Processes.- 7.3 Light Scattering Techniques in Heat Transfer.- 7.4 Concluding Remarks.- 8 Laser-Doppler Velocimetry.- 8.1 Introduction.- 8.2 Principles of LDV.- 8.3 Optics.- 8.4 Signal Processing.- 8.5 Seeding Particles.- 8.6 Determination of Characteristic Turbulence-Quantities.- 9 Phase Doppler Anemometry (PDA).- 9.1 Introduction.- 9.2 General considerations for the application of PDA.- 9.3 Principles of PDA.- 9.4 Measurement accuracy.- 9.5 Applications of PDA.- 10 Dynamic Light Scattering.- 10.1 Introduction.- 10.2 Overview.- 10.3 Light Scattering Theory.- 10.4 Experimental Methods.- 10.5 Measurement of Thermal Diffusivity.- 11 Raman Scattering.- 11.1 Introduction.- 11.2 Theoretical Basics of Raman Spectroscopy.- 11.3 Experimentalset-up.- 11.4 Selected Applications.- 11.5 Concluding Remarks.- 12 Laser induced Fluorescence.- 12.1 Introduction.- 12.2 Basic Principles of Laser Induced Fluorescence.- 12.3 Experimental Setup and Procedures.- 12.4 Selected Applications.- 12.5 Concluding Remarks.- 13 Absorption.- 13.1 Introduction.- 13.2 Line spectra.- 13.3 Experimental techniques.- 14 Pyrometry and Thermography.- 14.1 Introduction.- 14.2 Temperature Radiation.- 14.3 Method of Transmission.- 14.4 Radiation Receiver (Detector).- 14.5 Thermal Cameras - Thermography Image Systems.- 14.6 Pyrometers.- 14.7 Error Potential.- 14.8 Appendix.- 15 Tomography.- 15.1 Introduction.- 15.2 Integral Measurement Methods.- 15.3 Mathematical Reconstruction Methods.- 15.4 Implementations.- 16 Particle Image Velocimetry.- 16.1 Introduction.- 16.2 Hardware for the experimental set-up.- 16.3 Evaluation software.- 16.4 Three-dimensional flow.- 16.5 Applications.- Nomenclature.- References.
Riassunto
Increasing possibilities of computer-aided data processing have caused a new revival of optical techniques in many areas of mechanical and chemical engi neering. Optical methods have a long tradition in heat and mass transfer and in fluid dynamics. Global experimental information is not sufficient for de veloping constitution equations to describe complicated phenomena in fluid dynamics or in transfer processes by a computer program. Furthermore, a detailed insight with high local and temporal resolution into the thermo and fluiddynamic situations is necessary. Sets of equations for computer program in thermo dynamics and fluid dynamics usually consist of two types of formulations: a first one derived from the conservation laws for mass, energy and momentum, and a second one mathematically modelling transport processes like laminar or turbulent diffusion. For reliably predicting the heat transfer, for example, the velocity and temperature field in the boundary layer must be known, or a physically realistic and widely valid correlation describing the turbulence must be avail able. For a better understanding of combustion processes it is necessary to know the local concentration and temperature just ahead of the flame and in the ignition zone.
