Development and Application of Streakline Visualization in Hypervelocity Flows
NOTE: At the time of publication, the author Patrick Lemieux was not yet affiliated with Cal Poly.
A method for visualizing streaklines in hypervelocity flows has been developed. The method uses the high temperatures produced in hypervelocity flows to ablate small amounts of sodium deposited onto a wire stretched across the flow and to broaden the lines in the sodium spectrum. By using a dye laser, tuned to a wavelength close to one of the sodium D-lines, as the light source in shadowgraph or Schlieren visualization, streaklines seeded with sodium become visible through absorption and/or enhanced refractivity. The technique has been used to investigate the stability of the shear layer produced by the curved bow shock on a cylindrically blunted wedge. The results suggest that the shear layer is unstable, exhibiting structures with a wavelength that is comparable to half the nose radius of the body.
P. Lemieux and H. G. Hornung. "Development and Application of Streakline Visualization in Hypervelocity Flows" Experiments in Fluids 33.1 (2002): 188-195.
Available at: http://works.bepress.com/plemieux/2