Improved Atomic Oxygen Quantification Within the Earth's Upper Atmosphere Through Numerical Corrections

摘要

An established method to simulate the aerodynamic effects on in situ sounding rocket measurements is the direct simulation Monte Carlo method. However, very few three-dimensional steady and unsteady simulations with high resolution along a rocket trajectory exist. This study provides three-dimensional steady and unsteady simulations applied to the Second Coupling of Dynamics and Aurora experiment. The results show the validity of a steady-state approach through quantitative comparisons of steady and unsteady simulation results near the rocket's apogee. Steady-state solutions of the flowfield are presented at 2 km intervals along both the upleg and downleg trajectories. The numerical simulations verify the experimental results showing the strong influence of rocket orientation on concentration. Atomic oxygen correction factors, based on the ratio of undisturbed to disturbed flowfield concentrations, are obtained from the numerical results and applied to the experimental sensor data. These correction factors, when applied to unconnected Second Coupling of Dynamics and Aurora data sets, show a significant improvement over previous research results, particularly along the upleg trajectory, in terms of minimizing the effects of compressible flow aerodynamics on the atomic oxygen data.