Simulation of hypersonic flows using a detailed nitric oxide formation model

In this paper the extensive quasiclassical trajectory (QCT) study recently concluded [J. Chem. Phys. 104, 2825 (1996)] is used to model the kinetics of the primary NO formation reaction, N-2+O-->NO+N, in hypersonic nonequilibrium flows. The QCT data are used to obtain expressions for the thermal rate constant, reactant energy removal, and product energy disposal rates of this reaction. The QCT results are coupled with the continuum conservation flow equations, and these equations are used to simulate the Bow-Shock UltraViolet2 (BSUV2) flow at altitudes between 75 to 87.5 km. It is found that the use of the Macheret and Rich [Chem. Phys. 174, 25 (1993)] vibration-dissociation coupling model along with the QCT rates gives improvements in the NO concentration predictions at altitudes between 80 and 85 km. Also, it is found that the vibrational and rotational temperatures of NO are much higher than that of the N-2 and O-2 in the gas, in accordance with the BSUV2 measurements. The amount of NO produced in the flow fields at 87.5 km and above is found to be strongly dependent on the free-stream density of atomic oxygen. (C) 1997 American Institute of Physics.