Double-Wavelength Digital Particle Image Velocimetry

Digital Particle Image Velocimetry is a convenient method which is used to interpret digital images of fluid motion and transform them into velocity fields. In a DPIV system, two consecutive particle images were taken with a known time interval. The velocity of any point in the flow field can be analyzed by finding different position of particles in two images. To achieve a high velocity measurement the time interval should be as small as possible. Frame Straddling technology is widely used in DPIV system which highly depends on professional high speed camera. We describe in this paper a DPIV system based on multi-wavelength pulse laser beam illumination and multispectral imaging instead of Frame Straddling. In this system, the minimal time interval between two particle images is 50ns. The system has been validated in the lab and the result is also laid out in this paper.