Fluid motion investigation by the photochromic flow visualization technique

The development and application of the photochromic flow visualization method (PFV) in experimental hydrodynamics are described. Tracers in the form of colored lines with a lifetime of 20–300 s are created in a photochromic solution by pulse radiation for 10 −9 s. The displacement of the tracers in the flow is followed by a high-speed movie camera. The information given by the PFV method permits the flow pattern velocity distribution, localization of circulation, and stagnation zones as well as other characteristics of the flow to be found. Several applications are considered such as flows in channels with complicated shapes, flows behind prosthetic heart valves, and thermocapillary and thermogravitational convective flows in homogeneous and stratified liquids.