Accession Number:

ADA621975

Title:

Self-sustained Flow-acoustic Interactions in Airfoil Transitional Boundary Layers

Descriptive Note:

Final performance rept. 1 Apr 2012-31 Mar 2015

Corporate Author:

EMBRY-RIDDLE AERONAUTICAL UNIV DAYTONA BEACH FL

Personal Author(s):

• Golubev, Vladimir

Report Date:

2015-07-09

Pagination or Media Count:

9.0

Abstract:

This project conducted complementary experimental and numerical studies of flow-acoustic resonant interactions in transitional airfoils and their impact on airfoil surface unsteady pressure and acoustic signature. The symmetric NACA-0012 airfoil and the slightly cambered SD7003 airfoil at moderate incidence were tested in the free-jet anechoic wind tunnel of Ecole Centrale de Lyon. Measurements of wall pressure, far -field acoustic pressure and velocity fluctuations using the hot-wire anemometry were conducted. In addition, advanced post-processing techniques were applied High-accuracy numerical studies focused on selected transitional-flow regimes for NACA-0012 and SD7003 airfoils for which experimental measurements recorded strong flow-acoustic resonant interactions characterized by multiple-tone acoustic spectra. Numerical studies employed a 6th-order Navier-Stokes solver implementing low-pass filtering of poorly resolved high-frequency solution content to retain numerical accuracy.

Descriptors:

• *ACOUSTIC SIGNATURES
• *AERODYNAMICS
• *AIRFOILS
• *BOUNDARY LAYER
• ACOUSTIC WAVES
• ACOUSTICS
• AERODYNAMIC STABILITY
• AMPLIFICATION
• EXPERIMENTAL DATA
• FAR FIELD
• HIGH FREQUENCY
• HOT WIRE ANEMOMETERS
• LAMINAR FLOW
• LOW PASS FILTERS
• NUMERICAL ANALYSIS
• RESONANCE
• REYNOLDS NUMBER
• SELF OPERATION
• SOUND PRESSURE
• SPECTRA
• SURFACE PROPERTIES
• TURBULENT DIFFUSION
• VARIATIONS
• VELOCITY
• WALLS
• WIND TUNNELS

Subject Categories:

• Aerodynamics
• Acoustics
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE