Accession Number:

ADA156644

Title:

Measured Similarity Properties of Eddy Viscosity and Mixing Length in Three-Dimensional Turbulent Stern Flows

Descriptive Note:

Final rept.

Corporate Author:

DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD

Personal Author(s):

Report Date:

1985-05-01

Pagination or Media Count:

35.0

Abstract:

A comprehensive set of experimental turbulence data is presented for the stern region of simple three-dimensional models having 11, 21, and 31 elliptic transverse cross sections. Direct measurements of Reynolds stresses, turbulence kinetic energy, and mean velocity profiles are made by X hot-film anemometry. The values of eddy viscosity and mixing length are obtained from the measured Reynolds stresses and the mean velocity gradient. The experimentally- determined distributions of eddy viscosity and mixing length in the thick stern boundary layers are found to be smaller than values which have been proposed for thin boundary layers. Because eddy viscosity and mixing length models play an important role in stern boundary-layer calculations, a revised empirical mixing length model, which is assumed to be proportional to the square-root of the effective turbulence area, is proposed.

Subject Categories:

  • Theoretical Mathematics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE