An Experimental Investigation of Transverse Injection from Circular and Elliptical Nozzles into a Supersonic Crossflow.
Abstract
Transverse injection of helium and air through circular and elliptical nozzles into a supersonic cross flow was investigated using optical diagnostics and probe-based measurement techniques. Shadowgraph visualizations documented the global characteristics of the jet/freestream interaction. Rayleigh/Mie scattering allowed ensembles of digital images from several measurement planes in each case to be collected. Pitot and concentration probes were used in the helium injection cases. The images provide mean and standard deviation statistics, spreading and penetration characteristics, large-scale mixing and convective velocity information, bow and separation shock features, and two-dimensional spatial correlation fields. Results indicate that the elliptical nozzle produces jets with greater lateral spread and suppressed transverse penetration compared to the jets from the circular nozzle. Injectant molecular weight does not strongly affect the jet's penetration, although it leads to substantial compressibility differences that dramatically influence the characteristics of the large-scale shear layer structures and the entrainment and mixing occurring between the injectant and crossflow. Probe measurements provide quantitative comparisons of total pressure losses and mixing characteristics. Results suggest better near field mixing and lower total pressure losses in the elliptical injection flowfield.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1996
- Accession Number
- ADA317633
Entities
People
- Abdollah S. Nejad
- J. C. Dutton
- Mark R. Gruber
Organizations
- Wright Laboratory