Inviscid and Viscous CFD Analysis of Booster Separation for the Space Launch System Vehicle
Speaker: Derek Dalle, STC / Computational Aerosciences Branch, NASA Ames Research Center
Presentation
Abstract
NASA's new heavy-lift rocket, the Space Launch System (SLS), is preparing for its first flight in 2018. This first flight, called Exploration Mission 1, or EM-1, will carry an uncrewed Orion capsule on a circumlunar flight with a secondary crew of several small satellites to be delivered into interplanetary space.
One of the critical events during the mission occurs when the SLS core vehicle separates with two solid rocket boosters. Although the rocket is over 300 ft. long, the clearances between the core vehicle and the boosters after separation can be a few inches or less. As part of the effort to certify that the separation will be successful, a team of NASA engineers was tasked with developing an aerodynamic database to cover every possible orientation of the boosters and core for use in a detailed Monte Carlo trajectory simulation. A database was built using approximately 25,000 Cart3D simulations with 22 rockets firing in each of the simulations. In order to provide more information for uncertainty quantification, approximately 300 OVERFLOW solutions were also computed. A wind tunnel test was also performed at NASA Langley Research Center's Unitary Plan Wind Tunnel, and over 6,000 more Cart3D simulations on the wind tunnel geometry were used as an additional data source for the uncertainty quantification.
SLS recently passed its Critical Design Review in the summer of 2015, and now the focus shifts to independent review by the NASA Engineering & Safety Center (NESC) and Design Certification Review (DCR). The SLS aerodynamics team will continue to collect information and prepare for future versions of the SLS vehicle with even higher lift capabilities.
Biography
Derek Dalle is a STC employee in the Computational Aerosciences Branch at NASA Ames Research Center (ARC/TNA). He received his undergraduate degrees from the University of Minnesota in 2008 and a Ph.D. in Aerospace Engineering from the University of Michigan in 2013. Prior to joining the Ames staff, he worked with Raytheon Missile Systems in Tucson, AZ. Derek's primary focus is on the aerodynamics of the Space Launch System, which is scheduled to first fly in 2018. Derek's graduate research was directed mainly on the gas dynamics of hypersonic air-breathing propulsion systems with a focus toward developing operational guidelines. Currently, he is mostly interested in applied aerodynamics of vehicles approaching first flight. Particular issues include development and management of large databases, efficient use of wind tunnel and CFD data sources, and uncertainty quantification.