Joan Feigenbaum

Current approaches to beach and surf zone mine clearance depend on the dispensing of large numbers of darts from a parent missile or projectile. The mine clearance mission requires a uniform distribution of darts over the target area. The primary long-term goal of the present effort is to understand and characterize, through simulation and analysis, the important physics affecting dart dispersal during large dart-pack dispense events. In this effort, the MODS (Mine Obstacle Defeat System) configuration is considered. The MIDS configuration consists of packs of darts arranged along the longitudinal axis. A current configuration under investigation consists of 9 packs, with each pack consisting of hundreds of darts mounted in a hexagonal close packing arrangement. The aggregate number of darts is beyond what can be reasonably computed using existing viscous CFD approaches. Accordingly, deriving useful data on fullsized MODS configurations requires modeling that includes the relevant geometric efforts on the flowfield without necessarily modeling every dart. The results of efforts for 2007 are presented in this document. The three main efforts were: 1) Determination of Scaling Effects on Rotating MODS Dart Pack 2) CFD/Tunnel Test Validation 3) HPC Challenge Project. All simulations used the OVERFLOW-2 code, which is the premier overset-methods Navier-Stokes code developed by NASA.