Artemis II Post-flight Liftoff and Transition Sectional Load Simulations

Abstract

Simulations were conducted with the Kestrel computational fluid dynamics tool on the Space Launch System (SLS) at conditions along the Artemis II mission preliminary representative trajectory between Mach 0.1 and 0.5. The standard simulation settings used for liftoff and transition lineload (LLA) database development were used; although all database simulations usually have the same Mach and Reynolds number, these simulations varied Mach number per point but were otherwise comparable. All simulated conditions were lower total angle of attack than most SLS LLA cases but were observed to converge to similarly statistically stationary states. Although no flight data were available for comparison, RANS simulations with FUN3D using (very different) best practices for the ascent regime resulted in comparable distributed vehicle loads everywhere except the booster tails. It was observed in this region that, despite the low total angle of attack and Mach number, the presence of engine plumes that are simulated in the ascent best practices but not in the LLA best practices had a substantial effect on the booster sectional loads.