The DEBRIS software predicts the trajectories of debris particles shed by a space-shuttle launch vehicle during ascent, to aid in assessing potential harm to the space-shuttle orbiter and crew. The user specifies the location of release and other initial conditions for a debris particle. DEBRIS tracks the particle within an overset grid system by means of a computational fluid dynamics (CFD) simulation of the local flow field and a ballistic simulation that takes account of the mass of the particle and its aerodynamic properties in the flow field. The computed particle trajectory is stored in a file to be postprocessed by other software for viewing and analyzing the trajectory.

DEBRIS supplants a prior debris-tracking code that took ≈15 minutes to calculate a single particle trajectory: DEBRIS can calculate 1,000 trajectories in ≈20 seconds on a desktop computer. Other improvements over the prior code include adaptive time-stepping to ensure accuracy, forcing at least one step per grid cell to ensure resolution of all CFD-resolved flow features, ability to simulate rebound of debris from surfaces, extensive error checking, a built-in suite of test cases, and dynamic allocation of memory.

This program was written by Phillip C. Stuart of Johnson Space Center and Stuart E. Rogers of Ames Research Center. MSC-23945-1

Software Tech Briefs Magazine

This article first appeared in the September, 2009 issue of Software Tech Briefs Magazine.

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