Some techniques are discussed that aid in the flow visualization of rotor tip vortices using wide-field shadowgraphy. The use of a beam splitter is shown to provide a particularly important enhancement to the method when large fields or angles of view are required. The optical characteristics of the strobe, observation screen, and recording film are also shown to be important for maximizing the shadowgraph contrast. Finally, theoretical predictions of the shadowgraph contrast for a series of compressible vortices are compared to experimental contrast results with a view to estimating the general velocity profile, viscous core radius, and viscous diffusion rate of the tip vortices.
No takes yet. Share an insight, caveat, or question.
Bagai et al. (1993) studied this question.