Burial and mobility of underwater munitions vary under various environment characteristics such as waves, currents, sediment transport, and sea floor morphology. Timely prediction of sea-floor environment and munition‘s mobility including location and burial is crucial to assess characteristics of munitions underwater and their environment. The objective of this research is to develop a high fidelity, computationally efficient coupled ensemble sea-floor environment and 6 degrees of freedom (CESE6D) munition model to assess the environment conditions and to predict mobility of munitions.
The existing mine impact and subsequent burial models are the core six degrees of freedom (6-DOF) for underwater munitions. The impact burial model (i.e., IMPACT35) is for areas with muddy beds. The scour burial model (i.e., VORTEX-LATTICE) is for areas with non-muddy bed materials such as sand, gravel, and rock. This is because the munition planted in areas with muddy bed may sink upon impact, while munitions planted in areas of non-muddy bed undergo little impact burial, but subsequently bury through scour and liquefaction processes. The 6-DOF munition model has user-input model parameters such as bed and suspended load transport efficiencies and seabed drag coefficient for the near field. These parameters depend on the surrounding environmental conditions. Delft3D is an open source environment model to predict nearshore/coastal sea floor hydrodynamic and morphologic conditions that is being used by other SERDP researchers. The output of Delft3D serves as the forcing function for the munition model. The ensemble modeling enhances the quality of prediction.
This project will produce a high fidelity, user-friendly, computationally efficient CESE6D model for quick assessment of the environment and timely prediction of munitions’ location, burial, and mobility in variety of aquatic environments. The CESE6D will contribute to the evaluation of site conditions for underwater munition remediation actions and risk reduction.