Advances in Space Launch System Booster Separation CFD

The Space Launch System (SLS) employs two Space Shuttle derived Solid Rocket Boosters (SRBs) which separate from the SLS core while still experiencing appreciable aerodynamic loads. Creating an aerodynamic database for this phase of flight can be challenging due to the large number of independent variables needed to fully constrain the problem and the complex flow induced by exhaust plumes of the booster separation motors (BSMs) and core main engines impinging on other parts of the vehicle. This paper details recent efforts in generating aerodynamic databases for SLS during the booster separation event using viscous Computation Fluid Dynamic (CFD) simulations obtained using NASA’s FUN3D solver. Particular challenges faced when modeling a complex problem such as booster separation are presented. Reductions in database uncertainty were observed through the introduction of a physics-based covariance approach to building the database run matrix, eliminating infeasible booster location permutations that potentially skew final response surfaces. Uncertainty quantification buildup is shown using test cases outside of the main database. Code-to-code comparisons between the FUN3D and OVERFLOW solvers are also presented to further verify database
results.