Interaction of Surfactants with Shear Flows and Surface Waves

Abstract

The rapid increase in computing power in the past two decades has made it possible to numerically solve the exact equations of fluid motion over a moderate range of scales in time and space. And although the equations of motion for the flow in the air and in the sea, namely the Navier-Stokes equations, are well known, the boundary conditions for these equations are generally unknown at a surfactant-influenced gas/liquid interface such as the ocean surface. This is because the boundary conditions for these equations are functions of the intrinsic viscoelastic properties of the interface, general techniques for their measurements are not yet available. This problem is highly nonlinear, since the viscoelastic properties depend on the composition of the interface which varies in both time and space due to interfacial motion resulting from, e.g., wind, water currents and waves. Once these intrinsic properties are determined, then the (numerical) solution of the Navier-Stokes equations can fully predict the motion of the interface and its manifestations, including wave generation and dampening, as well as mass, momentum and energy transport across the interface. The long-term goals of this project are to develop the necessary instrumentation and techniques to noninvasively determine the dynamic (i.e. viscoelastic) properties of the ocean surface, as described by mechanics-based constitutive relations, and to relate these intrinsic properties to the apparent properties of the interface as interpreted by the usual phenomenological approach of wave-dampening. Ultimately, the intrinsic properties will be utilized in predictive computer models for the surfactant-influenced ocean surface.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1998
Accession Number
ADA569105

Entities

People

  • Amir H. Hirsa

Organizations

  • Rensselaer Polytechnic Institute

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Chemistry
  • Computational Fluid Dynamics
  • Engineering
  • Equations
  • Flow
  • Flow Fields
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Measurement
  • Mechanics
  • Physics Laboratories
  • Shear Flow
  • Stratified Fluids
  • Surface Waves
  • Waves

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Dynamics.
  • Marine Ecotoxicology

Technology Areas

  • Space