Laser Diagnostic Development and Measurement and Modeling of Turbulent Flowfields of Jets and Wakes. Part 1. Two-Dimensional Laser Doppler Anemometer Studies of Isothermal Flowfield in a Ducted Centerbody Combustor.

Abstract

A two-dimensional laser Doppler anemometer was designed to take measurements in a ducted coaxial flow system having a centerbody separating the jets. The measurements, made in isothermal flow, can be categorized as: central jet only (C02); annular jet only (air); and, combined central and annular jet flow. Radial profiles of the axial and radial/azimuthal velocity were obtained. The central jet only condition approximates a free jet since the central jet diameter is much smaller than the centerbody or duct diameter (1:29.3: 53.2). Measurements of the jet development (diameter, turbulence intensity, etc.) were compared with previous free jet studies. In a study of the isotropy of the turbulent fluctuations it was determined that fully developed turbulent flow begins further downstream than anticipated. Velocity profiles were combined with gas sampling measurements to ascertain jet entrainment. Results show a linear growth of the entrained mass starting at the entrance plane. Downstream (20 diameters) the rate of growth increases to match past studies in that region. The annular jet flow creates a recirculation vortex in the wake of the centerbody. The flowfield was mapped and the streamlines describing the flow were obtained throughout the recirculating flow and further downstream.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1983
Accession Number
ADA134691

Entities

People

  • A. J. Lightman
  • P. D. Magill
  • R. J. Andrews

Organizations

  • University of Dayton

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Sensors

DTIC Thesaurus Topics

  • Acousto-Optic Modulators
  • Annular Flow
  • Argon Lasers
  • Boundary Layer
  • Combustion
  • Computational Fluid Dynamics
  • Computer Programs
  • Computers
  • Detectors
  • Fluid Dynamics
  • Fluid Flow
  • Hydrodynamics
  • Jet Flow
  • Laser Beams
  • Reynolds Number
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Directed Energy