Development and Application of Light-Field Cameras in Fluid Measurements

Description

This book provides a comprehensive guide to 3D Light-Field camera based imaging, exploring the working principles, developments and its applications in fluid mechanics and aerodynamics measurements.  It begins by discussing the fundamentals of Light-Field imaging and theoretical resolution analysis, before touching upon the detailed optics design and micro-lens array assembly. Subsequently, Light-Field calibration methods that compensate for optical distortions and establish the relations between the image and real-word 3D coordinates are covered. This is followed by Light-Field 3D reconstruction algorithms which are elaborated for micrometer-scale particles and centimeter-scale physical models. Last but not least, implementations of the preceding procedures to selected fundamental and applied flow measurement scenarios are provided at the end of the book.  Development and Application of Light-Field Cameras in Fluid Measurements gives an in-depth analysis of each topic discussed, making it ideal as both an introductory and reference guide for researchers and postgraduates interested in 3D flow measurements. Preface Contents Contributors Abbreviations Symbols 1 Introduction The Light-field Capturing Light-field Would Light-field Imaging be Beneficial for PIV? References 2 Light-field Camera Working Principles Introduction Principles of Conventional Imaging Imaging Principles of Unfocused Light-field Camera Imaging Principles of Focused Light-field Camera Synthetic Image Generation and Point Source Response Light-field Camera Design Microlens Array Embedded-MLA Light-field Camera Relayed-MLA Light-field Camera Microlens Calibration Summary References 3 Volumetric Calibration for Light-field Camera with Regular and Scheimpflug Lens Calibration for Light-field Camera with Regular Lens Determination of Plenoptic Disc Feature Diameter and Centre Calculation of the Weighting Coefficient Simulation Studies Calibration Experiment Calibration for Light-field Camera with Scheimpflug Lens Plenoptic Disk Feature Extraction Calibration for Optical Distortions Calibration Experiment References 4 Light-field Particle Image Velocimetry Introduction Dense Ray Tracing-based MART 3D Reconstruction of Light-field Particle Images Reconstructed 3D Particle Elongations Reconstruction Quality and Speed Reconstruction Accuracy Under Unsteady Flow Conditions Experimental Validations Comparison with Tomo-PIV Synthetic Particle Image Generation and Analysis Dual-Camera LF-PIV Initial Validation of Dual Camera Principles Effects of Particle Density and Separation Angle Validations with Simulation and Experiment References 5 Simultaneous 3D Surface Geometry and Pressure Distribution Measurement Introduction Pressure Estimation from Central Perspective Images 3D Model Geometry Reconstruction from Single Light-field Image Application of Light-field PSP to Mach 5 Wind Tunnel Experiment References 6 Light-field PIV Implementation and Case Studies Introduction Adverse Pressure-Gradient Turbulent Boundary Layers Impinging Jets Linear Cascades Supersonic Jets References 7 Future Developments of Light-field-Based Measurements Light-field Multi-spectral Radiation Thermometry 3D Geometry Measurements Droplet and Splash Measurements 3D Flame Structure Reconstructions 3D Background Oriented Schlieren Summary References List of Formulas