A Systematic Experimental and Computational Investigation of a Class of Contoured Wall Fuel Injectors
Abstract
The performance of a particular class of fuel injectors for scramjet engine applications is addressed. The contoured wall injectors were aimed at augmenting mixing through axial vorticity production arising from interaction of the fueVair interface with an oblique shock. Helium was used to simulate hydrogen fuel and was injected at Mach 1.7 into a Mach 6 airstream. The effects of incoming boundary layer height. injector spacing, and injectant to freestream pressure and velocity ratios were investigated. Results from threedimensional flow field surveys and Navier-Stokes simulations are presented. Performance was judged in terms of mixing, loss generation and jet penetration. Injector performance was strongly dependent on the displacement effect of the hypersonic boundary layer which acted to modify the effective wall geometry. The impact of the boundary layer varied with injector array spacing. Widely-spaced arrays were more resilient to the detrimental effects of large boundary layers. Strong dependence on injectant to free stream pressure ratio was also displayed. Pressure ratios near unity were most conducive to losseffective mixing and strong jet penetration. Effects due to variation in mean shear associated with non-unity velocity ratios were found to be secondary within the small range of values tested.
Additional Information
© 1992 American Institute of Aeronautics and Astronautics. Inc. All rights reserved. Funding for this work was provided largely through NASA Grant NAG 1-842. The fundamentals of shock-enhanced mixing were developed earlier under Contract F49620-86-C-0113 administered by the Air Force Office of Scientific Research. The authors wish to thank many members of the technical staff at NASA Langley Research Center, particularly D. Bushnell, S. Robinson. M. Walsh, members of the Experimental Flow Physics Branch, and members of the Computational Methods Branch. The planar Rayleigh scattering data alluded to at several points in the discussion were the product of a collaborative effort with the Optical Spectroscopy Section of NASA Langley's Instrument Research Division. Supercomputing support was provided by the San Diego Supercomputer Center via a National Science Foundation Grant, the NASA Ames NAS facilities, the JPL/Caltech Cray, and the NASA Langley supercomputing facilities.Attached Files
Published - 328_Waitz_IA_1992.pdf
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Additional details
- Eprint ID
- 21069
- Resolver ID
- CaltechAUTHORS:20101130-132815278
- Created
-
2010-12-10Created from EPrint's datestamp field
- Updated
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2019-10-03Created from EPrint's last_modified field
- Caltech groups
- Guggenheim Jet Propulsion Center
- Series Name
- AIAA Papers
- Series Volume or Issue Number
- AIAA 92-0625
- Other Numbering System Name
- AIAA
- Other Numbering System Identifier
- 92-0625