Journal of Fluid Mechanics

Non-equilibrium dissociating nitrogen flow over a wedge

D. J.  Kewley a1 and H. G.  Hornung a1
a1 Department of Physics, Australian National University, Canberra

Article author query
kewley dj   [Google Scholar] 
hornung hg   [Google Scholar] 


Experimental results for dissociating nitrogen flow over a wedge, obtained in a free-piston shock tunnel, are described. Interferograms of the flow show clearly the curvature of the shock wave and the rise in fringe shift after the shock associated with the dissociation. It is shown that the shock curvature a t the tip of the wedge can be used to calculate the initial dissociation rate and that it is a more sensitive indication of the rate than can be obtained from fringe shift measurements under the prevailing experimental conditions. Because the free-stream dissociation fraction can be adjusted in the shock tunnel, the dependence on atomic nitrogen concentration of the dissociation rate can be determined by the shock curvature method. A detailed calculation of the flow field by an inverse method, starting from the measured shock shape, shows good agreement with experiments.

(Published Online March 29 2006)
(Received June 1 1973)
(Revised February 2 1974)