Accession Number:

ADA191470

Title:

Noise Generation and Boundary Layer Effects in Vortex-Airfoil Interaction and Methods of Digital Hologram Analysis for these Flow Fields.

Descriptive Note:

Interim periodic rept. no. 1, 11 Sep-28 Nov 87,

Corporate Author:

MAX-PLANCK-INST FUER STROEMUNGSFORSCHUNG GOETTINGEN (GERMANY F R)

Personal Author(s):

• Meier, G. E.

Report Date:

1987-11-30

Pagination or Media Count:

6.0

Abstract:

The mechanism of sound generation and the kind of viscid interaction of vortices with airfoils in an airflow is investigated. Experiments have been performed in regular, quasi-stationary flow with vortices of a Karman vortex street. Depending on the dimensions of vortices and airfoils, their distance, and the flow Machnumbers, different kinds of upstream propagating sound waves occur. Keywords Noise, Boundary layer, Vortex airfoil interaction, Secondary vortex, Vortex noise, Digital interferogram analysis, Fringe evaluation, Image processing.

Descriptors:

• *AIRFOILS
• *VORTICES
• *FLOW NOISE
• *BOUNDARY LAYER FLOW
• *FLOW VISUALIZATION
• *HOLOGRAMS
• AIR FLOW
• BOUNDARY LAYER
• DIGITAL SYSTEMS
• FLOW FIELDS
• HOLOGRAMS
• IMAGE PROCESSING
• INTERACTIONS
• INTERFEROGRAMS
• NOISE GENERATORS
• SECONDARY
• SOUND WAVES
• SYSTEMS ANALYSIS
• TEST AND EVALUATION
• VISCOUS FLOW
• WAVE PROPAGATION

Subject Categories:

• Fluid Mechanics
• Acoustics
• Holography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE