Laser Velocimeter Measurements in Moderately Heated Jet Flows
Abstract
Laser velocimeter (LV) measurements are presented for the developing velocity field of a subsonic jet and an underexpanded jet into quiescent air at nominal stagnation temperatures of 500 and 1,000 R. Severe particle lag effects were encountered in the under-expanded jet so that data presentation is limited to the centerline mean axial velocity and probability distributions for exit-to- ambient static pressure ratios of 2 and 4 at axial stations up to 5 nozzle diameters downstream of the nozzle exit. Data were obtained with a two- component, Bragg-diffracted, individual realization system operated in a backscatter mode. Since the flow was unseeded, the measurements relied on naturally occurring flow contaminants to serve as scatter centers for the LV. Particle dynamics calculations for the two flows are used in conjunction with an analysis of the detection characteristics of the system to develop a theoretical limit for the minimum level of turbulence detectable by an LV.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1977
- Accession Number
- ADA038283
Entities
People
- D. O. Barnett
- T. V. Giel Jr.
Organizations
- Arnold Engineering Development Complex