DEPARTMENT OF AEROSPACE AND OCEAN ENGINEERING

Steady Flow Over a 6:1 Prolate Spheroid 

Flow about a 6:1 Prolate Spheroid at 20 Angle of Attackalpha=20, x/L=0.772, Secondary Streamlines with Contours of Turbulent Kinetic Energy
 

ABSTRACT

Velocity measurements were carried out on the lee-side of a 6:1 prolate spheroid, ReL= 4.2´106, at 10° and 20° angles of attack(a), and at x/L= 0.600 and 0.772.  The dominant feature of each of these flowfields is the presence of a shed vortex due to cross-flow separation.  This is a source of considerable noise and vibration.  At a = 10°, high turbulence levels is confined to the near-wall region.  At a= 20°, the highest turbulence levels were measured away from the wall at azimuthal (f) locations where the flow is separating.  Velocity spectra for regions with weaker 3-D effects exhibit features that are observed for equilibrium flows.  Spectra in strong vortical flow regions show unusual and apparently non-equilibrium behavior.  This behavior has some qualitative similarities with the surface pressure fluctuation spectra .
 
 

RELATED PUBLICATIONS
(Contain analysis of this data)


Goody, M. C., Simpson, R. L., Engel, M., Chesnakas, C. J., and Devenport, W. J., 1998,"Mean Velocity and Pressure and Velocity Spectral Measurements within a Separated Flow Around a Prolate Spheroid at Incidence," AIAA Paper 98-0630
Chesnakas, C. J., Simpson, R. L., and Madden, M. M., 1993, "Three Dimensional Velocity Measurements on a 6:1 Prolate Spheroid," Data Report VPI-AOE-202, Dept. of Aero & Ocean Engr, VPI&SU, Blacksburg, VA
Chesnakas, C. J., and Simpson, R. L., 1994, "Full Three-Dimensional Measurements of the Cross-flow Separation Region of a 6:1 Prolate Spheroid," Experiments in Fluids, Vol. 17, pp. 68-74.
Chesnakas, C. J., and Simpson, R. L., 1996, "Measurements of the Turbulence Structure in the Vicinity of a 3-D Separation, " Journal of Fluids Engineering, Vol. 118, No. 1, pp. 268-275.
Chesnakas, C. J., and Simpson, R. L., 1997, "A Detailed Investigation of the 3-D Separation about a 6:1 Prolate Spheroid at Angle of Attack," AIAA Journal, Vol. 35, No. 6, pp. 990-999.
Wetzel, T. G., 1996, "Unsteady Flow Over a 6:1 Prolate Spheroid," Ph.D Dissertation, Dept. of Aero & Ocean Engr, VPI&SU, Blacksburg, VA.   DATA AVAILABLE ON WEB

 

DATA AVAILABLE FOR DOWNLOADING

The following files contain LDV and hot-wire velocity measurements of the flow about a 6:1 prolate spheroid at incidence. The *.XLS files are Microsoft Excel workbook files. Some additional flow documentation is given in the *.PDF file as indicated below.  You will need the Adobe Acrobat Reader in order to read the *.PDF file.  The Adobe Acrobat Reader is available from Adobe free of charge by clicking on this link: Get Acrobat Reader .

NOTE:  THE OUTER LAYER BOUNDARY LAYER VARIABLES (d*, q, Ue) GIVEN HERE SUPERCEDE THE VALUES POSTED IN THE JOURNAL OF FLUIDS ENGINEERING DATABANK

Flow about the Leeside of a 6:1 Prolate Spheroid at Angle of Attack
Flow Documentation  (DOC.PDF : 33 KB)
Contains relevant boundary layer parameters (e.g. flow velocity, boundary layer thickness, etc.)
Data Files
    a = 10°, x/L = 0.600 (16V.XLS : 161 KB)
    a = 10°, x/L = 0.772 (17V.XLS : 226 KB)
    a = 20°, x/L = 0.600 (26V.XLS : 232 KB)
    a = 20°, x/L = 0.772 (27V.XLS : 236 KB)

For more information, e-mail Professor Roger L. Simpson.
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