Accession Number:

ADA000841

Title:

Holographic Visualization of Compressor Blade Wake Interaction.

Descriptive Note:

Final technical rept. 19 Mar 73-19 Jan 74,

Corporate Author:

PRATT AND WHITNEY AIRCRAFT EAST HARTFORD CONN

Personal Author(s):

• Arnoldi,Robert A.

Report Date:

1974-03-25

Pagination or Media Count:

40.0

Abstract:

Successful holographic studies were made of unsteady aerodynamic effects within the stator passage of a single-stage test compressor operating at tip speeds between 1400 and 1600 feet per second. A shock wave associated with the rotor trailing edge was observed to reflect from the stator vanes, producing a characteristic downstream array of shock segments. This array possesses a helical structure which will excite propagating acoustic modes of duct, and will affect the interpretation of instrument readings and of downstream noise phenomena. A systematic variation of density gradients was observed within the stator passages, consistent with a wake transport theory previously developed by Kerrebrock and Mikolajczak. Both point-source and diffuse-background holograms were employed, the latter in the form of double exposures which yielded shearing differential interferograms.

Descriptors:

• *FLOW VISUALIZATION
• *WAKE
• *COMPRESSORS
• *COMPRESSOR BLADES
• SHOCK WAVES
• TURBULENT FLOW
• HOLOGRAPHY
• TRAILING EDGES
• ROTOR BLADES(TURBOMACHINERY)

Subject Categories:

• Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE