Multiscale plume modeling of the Deepwater Horizon oil-well blowout for environmental impact assessment and mitigation
Abstract
The accidental blowout plume of the Deepwater Horizon (DH) oil well is an unprecedented event that will have far-reaching environmental, economic, and societal impact. The subsurface structure of the blowout plume, including its layered system of intrusions, conforms qualitatively to that predicted in the literature; however, new modeling tools are currently needed to produce highly-resolved predictions of such a complex plume in the stratified and flowing ocean. We present laboratory experiments of multiphase plumes in stratification and crossflow to understand the physical mechanisms that lead to separation among the buoyant dispersed phases (oil and gas) and the entrained and dissolved constituents in the continuous phase. Scale analysis indicates that the DH plume is stratification dominated, and observed locations of hydrocarbon intrusion layers agree well with the experimentally derived empirical scaling laws. New flow visualization measurements in gas plumes in stratification demonstrate that unsteady plume oscillation and detrainment events result from regular shedding of coherent structures on the order of the plume width and are not directly related to the stratification frequency. Similar particle image velocimetry (PIV) measurements in weak crossflows characterize the transport mechanisms in the plume wake. The results of these experiments will be used in the context of a National Science Foundation RAPID grant to validate a nested large eddy simulations (LES) / Reynolds averaged Navier-Stokes (RANS) model of the DH plume, and early results from this model demonstrate its feasibility to capture the unsteady and complex structure of the plume evolution.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMOS33C1479S
- Keywords:
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- 4203 OCEANOGRAPHY: GENERAL / Analytical modeling and laboratory experiments;
- 4251 OCEANOGRAPHY: GENERAL / Marine pollution;
- 4534 OCEANOGRAPHY: PHYSICAL / Hydrodynamic modeling;
- 4568 OCEANOGRAPHY: PHYSICAL / Turbulence;
- diffusion;
- and mixing processes