Validation of High-Temperature Air Reaction and Relaxation Models Using Emission Data

摘要

The analysis of infrared (IR) and ultraviolet (UV) emissions in hypersonic air flows is performed using conventional and high-fidelity direct simulation Monte Carlo approaches, with the objective of distinguishing between models of various high-temperature processes. A comparison between the computational results and the available shock-tube data is conducted for IR intensities in the 5-5.5 mu m NO band at relatively low freestream velocities from 2.97 to 3.87 km/s, and UV spectra of NO at a high velocity of 6.81 km/s. For all conditions, the high-fidelity model provides good agreement with the data. Little impact of the model refinement is observed at low velocities. At the high velocity, the equilibrium constant and the energy disposal for the N2+O exchange reaction, as well as the vibrational coupling of nitrogen dissociation, play a significant role and warrant further study.