ABSTRACT
The literature abounds in flow visualization methods and their application to a very large range of situations. This chapter presents techniques for the visualization of air and water (liquid) flows. The principle for each technique is provided in addition to implementation details, equipment used, sources for procurement, and example visualizations. The chapter presents the holographic interferometry technique and example visualizations. Smoke entrainment is the most common visualization technique for laminar air flows, but has somewhat limited use in turbulent flows due to its rapid diffusion by turbulent mixing. Flow visualization is usually easier to perform in water, and also yields better quality results. As a result, water-flow tunnels are frequently used to study air flows by testing scale models at low velocity. As with smoke visualization, dye entrainment is successful mostly in laminar flow. The enhanced mixing in turbulent flow causes the dye streaks to diffuse too rapidly to be of value as tracers.
