Massively Scalable Mixture Model for Small-scale Sand Ripples

Abstract

Our long-term goal is to develop a modeling framework to predict sediment transport, the evolution of seafloor roughness, and acoustic propagation through the seafloor in the near shore and littoral battlespace environment. The primary objective of this project is to implement a massively parallel version of an existing mixture model, SedMix3D, for simulating small-scale ripple dynamics in shallow littoral environments. The applicability of the existing serial version of SedMix3D is severely hampered by the physical limitations (memory and CPU speed) of typical desktop workstations. The scalable version of SedMix3D developed here will be able to simulate prototype size domains found in the center of a laboratory U-tube (up to 1 m in length). The parallel version of SedMix3D is a powerful research tool that will be used to study the details of small-scale sand ripple dynamics, including the following: (1) the effects of suspended sediment concentration on turbulence modulation, (2) the dynamics of ripple transitions from 2D to 3D (and back to 2D) under changing forcing conditions, and (3) the role of terminations and bifurcations on ripple migration and growth rates. SedMix3D treats the fluid-sediment mixture as a single continuum with effective properties that parameterize the fluid-sediment and sediment-sediment interactions using several closures for the sediment phase. The capability of SedMix3D to simulate small-scale sand ripple dynamics has been illustrated both qualitatively and quantitatively. The research tool developed here will be used to improve understanding of bedform dynamics, and more generally, bottom boundary layer physics in shallow sandy environments.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2009
Accession Number
ADA527053

Entities

People

  • A. Penko
  • Joseph Calantoni

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Boundaries
  • Boundary Layer
  • Coastal Engineering
  • Dynamics
  • Earth Sciences
  • Environment
  • High Resolution
  • Layers
  • Military Research
  • Models
  • Naval Operations
  • Navy
  • Sedimentation
  • Sediments
  • Suspended Sediments
  • Three Dimensional

Readers

  • Coastal Oceanography
  • Computational Modeling and Simulation