Geometry Effects on Steady and Acoustically Forced Shear-Coaxial Jet Sprays
Abstract
The mixing process on four shear-coaxial injectors with different outer-to-inner jet area ratios and varying inner jet post thickness is examined experimentally. The experiments were conducted at ~1.5MPa with varying outer-to-inner jet momentum flux ratios (0.5 - 20), with and without a pressure antinode perturbation at the jet exit. Nitrogen was used as the test fluid. High speed back-lighting movies, acoustic pressure measurements and temperature exit profiles are the main diagnostics used. Proper orthogonal decomposition was applied to the intensity fluctuation of the high-speed images to extract spatial and temporal characteristics of the dominant flow structures. The extent of the influence of outer-to-inner momentum flux ratio on mixing was dependent on the injector geometry. The inner jet lengths for a large outer-to-inner jet area ratio injector were more influenced by increasing momentum flux ratios. Regardless of injector geometry, lower momentum flux ratio (generally less than 5) flows were found to be more responsive to acoustic forcing. With increasing momentum flux ratio, the flow response to forcing depended on the injector geometry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 2012
- Accession Number
- ADA589366
Entities
People
- Ann Karagozian
- D. Talley
- I. A. Leyna
- S. Teshome
Organizations
- Air Force Research Laboratory