AVERAGE TEMPERATURES AND TEMPERATURE FLUCTUATIONS BEHIND A HEATED WIRE

Abstract

The turbulent diffusion process in air was studied by measuring temperatures as a function of position in the wake of an electrically heated wire stretched across a round pipe. The Reynolds number based on the three-inch diameter of the pipe was ten thousand. Traverses were made behind a 0.0126-inch diameter wire at distances ranging from 0.10 inch to 18 inches. The time average temperature profiles and the mean-square fluctuating temperature profiles were measured by single resistance thermometers; and mean fluctuating temperature products by two resistance thermometers separated by from 0.026 to 0.608 inches. The data were compared to Taylor's single-particle diffusion theory; to Batchelor's particle-pair and particle-cloud diffusion theory; to Townsend's analysis of diffusion from a line source in homogeneous turbulence; and to smooth and rough wandering plume models. A structural function (after Obukhov) was also calculated. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1961
Accession Number
AD0255954

Entities

People

  • Glen F. Crum
  • Thomas J. Hanratty

Organizations

  • University of Illinois Urbana–Champaign

Tags

DTIC Thesaurus Topics

  • Diameters
  • Diffusion
  • Diffusion Theory
  • Particles
  • Resistance
  • Resistance Thermometers
  • Reynolds Number
  • Thermometers
  • Turbulence
  • Turbulent Diffusion

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Mechanics and Fluid Dynamics.
  • Thermal Physics or Thermal Science.