Length Scales of Turbulence Near a Free Surface

Abstract

Two-point correlations, energy spectra, and length scales are examined in the vicinity of a free surface, modeled as a shear-free boundary in a direct numerical simulation of open channel flow. The length scale results indicate that a typical eddy is flattened as it interacts with the surface. The scales associated with the vertical component of velocity seem to determine the extent of the source layer described in the Hunt-Graham model. The energy spectra show qualitative agreement with the model, though higher resolution calculations will be required to make more quantitative comparisons. Additionally, the proximity of the free surface to the bottom solid wall of the channel evidences itself as a wall-layer streaky structure which persists to a noticeably greater distance away from the wall. Some speculations are offered to explain this effect.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1991
Accession Number
ADA245330

Entities

People

  • J. D. Swearingen
  • R. A. Handler
  • R. I. Leighton
  • T. F. Swean Jr.

Organizations

  • Leidos

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Boundary Layer
  • Channel Flow
  • Computational Fluid Dynamics
  • Dynamics
  • Equations
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Froude Number
  • Mechanical Engineering
  • Mechanics
  • Military Research
  • Molecular Dynamics
  • Reynolds Number
  • Simulations
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Fluid Mechanics and Fluid Dynamics.