Speaker
Description
Multiphysics simulations involve a number of modeling choices, including material strength, meshing strategies, and equation of state. These methods are often verified using ideal scenarios (e.g., uniform mesh, analytic solutions available), but there are scenarios during which this approach is not feasible. Planetary defense, a research subject focused on protecting Earth from impacts from potentially hazardous objects (PHOs), is a matter of both national and global security. Simulations of planetary defense applications involve spatial scales of hundreds of kilometers and temporal scales on the order of seconds or longer. Thus, modeling choices must be made to ensure that knowledge can be obtained in a timely manner, as mission design can take years and flight time from Earth to a PHO can take from 6 months up to years. Understanding how these choices (e.g., a varied mesh resolution that is more resolved around the impact point and less resolved at the edges) contribute to overall uncertainty is of utmost importance in preparation for a variety of potentially catastrophic scenarios. In this work, we examine how specific modeling choices contribute to uncertainties in numerical simulations as a means of better understanding how to best interpret results and apply the appropriate error bars given a time-sensitive scenario, such as an impending meteor strike. We also discuss the simulations run as part of the Near Earth Object Table Top Exercise of 2024, which considered a number of possible mitigation strategies and associated timelines.