TURBULENCE IN THE NOISE-PRODUCING REGION OF A CIRCULAR JET,
Abstract
Measurements in a 2 in. cold air jet at M=0.3 have shown that about a quarter of the Reynolds shear stress is produced by large eddies with a rather narrow range of wavelengths. It is deduced from the nine orthogonal spatial correlations that these eddies take the form of mixing jets, inclined to the radial direction in any cross-sectional plane. The same eddies appear to dominate the near-field pressure fluctuations. The large-eddy intensity and shear stress contribution decrease at distances from the exit of more than two or three diameters. The artificial modification of these well-defined eddies seems to offer the best hope of increasing the jet mixing rate and permitting noise reduction by the use of acceptably short ejector shrouds. Measurements leading to a turbulent energy balance are also described. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1963
- Accession Number
- AD0436671
Entities
People
- D. H. Ferriss
- P. Bradshaw
- R. F. Johnson
Organizations
- AGARD