A series of experiments studying hypervelocity nitrogen flow over double-cone geometries has been conducted in the T5 Shock tunnel at the California Institute of Technology. Holographic interferometry was used to visualize the flow. These experiments were designed to test thermochemical models used in hypersonic flow computations, and the geometries were chosen specifically to produce flow fields sensitive to the effects of finite rate chemistry. Comparisons between the experimental and computational interferograms show that the computations cannot reproduce the experimental results. The reasons for the differences between the computations and experiments are the uncertainties in both equilibrium and nonequilibrium dissociation rates for nitrogen. The double-cone flow fields with a large separation zone are much more sensitive to the chemical rates than blunt body flow fields. Until the equilibrium dissociation rates for nitrogen are known more accurately, it is impossible to asses the validity of current vibration-dissociation coupling models.
|Original language||English (US)|
|State||Published - 1997|
|Event||32nd Thermophysics Conference, 1997 - Atlanta, United States|
Duration: Jun 23 1997 → Jun 25 1997
|Other||32nd Thermophysics Conference, 1997|
|Period||6/23/97 → 6/25/97|
Bibliographical noteFunding Information:
The experimental results could have not have been obtained without the help of Bahram Valiferdowski, Ivett Leyva, Jean-Paul Davis, Patrick Lemieux, and Philippe Adam at GALCIT. This work was supported by the Air Force Office of Scientific Research Grant Number F49620-93-1-0338. Computer time was provided by the Minnesota Supercomputer Institute. This work is also sponsored in part by the Army High Performance Computing Research Center under the auspices of the Department of the Army, Army Research Laboratory cooperative agreement number DAAH04-95-2-0003/contract number DAAH04-95-C-0008, the content of which does not necessarily reflect the position or the policy of the government, and no official endorsement should be inferred.