Composing Flow-Streak Images From Colorized Particle Images

A method for making a flow visible in a plane and determining in-plane velocities involves the digitization and digital processing of a sequence of monochrome video images of particles entrained in the flow. The particle-laden flow passes through a sheet of laser or lamp light in the plane, which is oriented perpendicularly to the viewing direction. As described thus far, this method involves the use of techniques that have become common in the flow-visualization art and that have been described in numerous articles in NASA Tech Briefs. The unique aspects of the present method originate in the following critical digital image-processing steps: