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


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a621975.pdf


Report Date : 09 Jul 2015


Pagination or Media Count : 9


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