Spray Statistics and the Impact of Geometry in Gas-Centered Swirl Coaxial Injectors
Abstract
Optically dense sprays are often encountered in propulsion applications such as rocket engines. The density of these sprays prevents measurement of droplet diameters and quantitative assessment of spray quality. The lack of quantitative data hinders the development of design criteria and complicates the formation of a fundamental understanding of the impact changes to injector geometry make in an engine's performance. While recent strides have been made in attaining qualitative data on a particular injector - a Gas-Centered Swirl Coaxial injector - with a very dense spray, droplet measurements and spray statistics have remained elusive. The current work presents the first of such quantitative measurements -- measurements achieved using time-resolved x-ray radiography. Details are given on a new experimental set-up used to produce relevant flow conditions at Argonne National Laboratory's Advanced Photon Source and the data processing used to extract droplet diameters and velocities. These extracted data are then used to assess how changes in the geometry of a GCSC injector alter the spray. Changes in liquid inlet diameter and liquid swirl number are shown to impact the spray in unexpected ways. The effect of injector outlet diameter changes and the downstream evolution of the spray are also discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2012
- Accession Number
- ADA572195
Entities
People
- Alan Kastengren
- Malissa D. Lightfoot
- Stephen A. Danczyk
- Stephen Alexander Schumaker
Organizations
- Air Force Research Laboratory