Coaxial Jets at Supercritical Conditions in a Variable Transverse Acoustic Field (Preprint)
Abstract
An experimental study on the effects of the relative position of a coaxial jet with respect to an externally-imposed transverse acoustic field is presented. A thorough investigation on the effects of chamber pressure, outer to inner jet velocity ratio (VR), and outer to inner momentum flux ratio (MR) on a coaxial jet subject to a fixed transverse acoustic field has been completed by this group [1-3]. However, the jet was located at a pressure node and its location was fixed. The main objective of this study is to investigate the effects on the dark-core length and its standard deviation of varying acoustic pressure and velocity fields at the coaxial jet center. The first resonant transverse frequency for this system is about 3 kHz and it is fixed throughout the study. The chamber reduced pressure, Pr, is about 1.5. At a pressure antinode, the maximum p' is about 6% of the chamber pressure. The shear coaxial injector used here is similar to those used in cryogenic liquid rockets. The working fluid for the inner and outer jet and the chamber pressurant is N2 to separate chemistry effects from the effects of a transverse acoustic on non-combusting phenomena such as jet mixing, atomization, and vaporization. Such interactions are thought to play an important role on liquid rocket combustion instabilities. Furthermore, by using a single fluid, ambiguities associated with composition dependence on mixtures critical properties are eliminated.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 24, 2007
- Accession Number
- ADA477921
Entities
People
- Bruce Chehroudi
- Ivett Leyva
- Juan Rodriguez
Organizations
- Air Force Research Laboratory