Turbulence Modeling for Free-Surface Flows

Abstract

The purpose of this effort was to establish the ability of existing engineering turbulence models to predict free-surface turbulent flows, and to lay the groundwork for improved modeling of these flows. The effort had an experimental component, a modeling component, and a instrumentation development component. Data were acquired to initialize and validate Reynolds averaged Navier Stokes (RANS) calculations of free-surface jet flows. This data has been made available to the community via the internet. An existing surface-ship RANS code was adapted to the jet problem and using the acquired data as initial conditions, the evolution of the jets was predicted using a standard k-epsilon turbulence model. This model was evaluated for its ability to predict the features of the free surface jets, and found incapable of predicting the rapid spreading of the jet near the surface. This was traced to its inability to represent the turbulence anisotropy which develops near the free surface in low-Froude-number flows. To support the experimental component of the program, as well as future efforts, a single point, high resolution, laser induced fluorescence surface elevation measurement system was developed, and new laser velocimeter signal processing hardware was acquired. The surface elevation measurement system was successfully completed and is currently being brought on line.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1997
Accession Number
ADA338778

Entities

People

  • Dave Walker

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Computational Fluid Dynamics
  • Engineering
  • Equations
  • Experimental Data
  • Flow
  • Fluid Dynamics
  • Fluid Flow
  • Froude Number
  • High Resolution
  • Instrumentation
  • Jet Flow
  • Laser Induced Fluorescence
  • Laser Velocimeters
  • Measurement
  • Turbulence
  • Turbulent Flow
  • Velocimeters

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)
  • Computational Modeling and Simulation
  • Marine Hydrodynamics

Technology Areas

  • Directed Energy