Preliminary Study of the Reacting Flow from Multi-Element Shear Coaxial Flows (Conference Paper with Briefing Charts)
Abstract
The reacting flow dynamics from a linear array of three shear coaxial injectors operating under sub-critical pressures was investigated. High-speed images recorded the center injectors response and behavior under the influence of its neighboring injectors for both acoustically unforced and forced conditions. The injectors employed liquid rocket engine relevant propellants of gaseous hydrogen and liquid oxygen. High-speed shadowgraph images along with OH* chemiluminescence captured the hydrodynamic instabilities for each injector and the flame interactions. Overlapping OH* chemiluminescence on top of the shadowgraph images, similar vortex/flame interactions were observed as were observed for a single jet for each individual jet from the injector. Spectral analysis on the OH* chemiluminescence in the near field shows that the individual flames share similar frequency fluctuations when the multi-element array was not subjected to acoustic forcing. These frequencies were also present in the dynamic mode decomposition of the shadowgraph and OH* chemiluminescence images used to investigate the modal structures of both the LOX jet and flame, respectively. Under acoustic forcing, the modal structures of both the LOX jet and flame are the same from each injector.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 21, 2018
- Accession Number
- AD1078102
Entities
People
- Douglas G. Talley
- Mario Roa
Organizations
- Air Force Research Laboratory