Accession Number : ADA317633

Title :   An Experimental Investigation of Transverse Injection from Circular and Elliptical Nozzles into a Supersonic Crossflow.

Descriptive Note : Final rept. Jan 93-Jan 96,

Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Gruber, Mark R. ; Nejad, Abdollah S. ; Dutton, J. C.

PDF Url : ADA317633

Report Date : JAN 1996

Pagination or Media Count : 327

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.

Descriptors :   *TURBULENT FLOW, *COMPRESSIBLE FLOW, *SUPERSONIC FLOW, PRESSURE GRADIENTS, SPATIAL DISTRIBUTION, SHOCK WAVES, AIR FLOW, OPTICAL IMAGES, VORTICES, FLOW VISUALIZATION, PRESSURE MEASUREMENT, MIE SCATTERING, LASER APPLICATIONS, FLOW FIELDS, WIND TUNNEL TESTS, HELIUM, MACH NUMBER, FREE STREAM, FLOW SEPARATION, PRESSURE DISTRIBUTION, SUPERSONIC NOZZLES, NOZZLE GAS FLOW, SHEAR FLOW, BOUNDARY LAYER FLOW, SPARK SHADOWGRAPH PHOTOGRAPHY, CROSS FLOW, JET MIXING FLOW.

Subject Categories : Fluid Mechanics
      Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE