Flow Field Measurements by Particle Image Velocimetry (PIV) Techniques

This chapter discusses the fundamental principles of Particle Image Velocimetry (PIV) for detailed, instantaneous velocity measurements. The history of two-dimensional PIV experiments is presented, and this discussion leads into the physics of PIV. The basic system components for traditional PIV experiments are discussed along with particle seeding requirements. In addition, the general methodology for image processing is included. Image acquisition and processing are demonstrated through detailed examples. In addition to velocity measurements, the use of PIV for turbulence measurements (vorticity, turbulence intensity, turbulent kinetic energy, and Reynolds stress) is also shown. Finally, recent advancements in PIV are briefly introduced: high-speed PIV, stereoscopic-PIV, and tomographic-PIV.