An aeroacoustic study of a leading edge slat configuration

Aeroacoustic evaluations of high-lift devices have been carried out in the Quiet Flow Facility of the NASA Langley Research Center. The present paper describes detailed flow and acoustic measurements that have been made in order to better understand the noise generated from airflow over a wing leading edge slat configuration, and to possibly predict and reduce this noise source. The acoustic database is obtained by a moveable Small Aperture Directional Array of microphones designed to electronically steer to different portions of models under study. The slat is shown to be a uniform distributed noise source. The data was processed such that spectra and directivity were determined with respect to a one-foot span of slat. The spectra are normalized in various fashions to demonstrate slat noise character. In order to equate portions of the spectra to different slat noise components, trailing edge noise predictions using measured slat boundary layer parameters as inputs are compared to the measured slat noise spectra.

[1]  William M. Humphreys,et al.  Aeroacoustic Measurements of a Wing-Flap Configuration , 1997 .

[2]  Julie Hayes,et al.  AIRFRAME NOISE CHARACTERISTICS OF A 4.7% SCALE DC-10 MODEL , 1997 .

[3]  Jr William M. Humphreys,et al.  Design and Use of Microphone Directional Arrays for Aeroacoustic Measurements , 1998 .

[4]  R. C. Nelson,et al.  Experimental Investigation of the Confluent Boundary Layer of a High-Lift System , 2000 .

[5]  M G Macaraeg,et al.  Fundamental Investigations of Airframe Noise , 1998 .

[6]  Mehdi R. Khorrami,et al.  Time-Accurate Simulations and Acoustic Analysis of Slat Free Shear Layer , 2002 .

[7]  Thomas F. Brooks,et al.  Airfoil self-noise and prediction , 1989 .

[8]  Jr William M. Humphreys,et al.  Effect of Directional Array Size on the Measurement of Airframe Noise Components , 1999 .

[9]  Bruce L. Storms,et al.  Aeroacoustic measurements of slat noise on a three-dimensional high-lift system , 1999 .

[10]  Michael Pott-Pollenske,et al.  Slat Noise Source Studies for Farfield Noise Prediction , 2001 .

[11]  Mehdi R. Khorrami,et al.  Unsteady Flow Computations of a Slat with a Blunt Trailing Edge , 1999, AIAA Journal.

[12]  Renaud Davy,et al.  AIRFRAME NOISE CHARACTERISTICS OF A 1/11 SCALE AIRBUS MODEL , 1998 .

[13]  Kiyoshi Nagakura,et al.  Airframe Noise Studies on Wings with Deployed High Lift Devices , 1998 .

[14]  Y. P. Guo,et al.  A MODEL FOR SLAT NOISE GENERATION , 1997 .

[15]  G. M. Lilley,et al.  THE PREDICTION OF AIRFRAME NOISE AND COMPARISON WITH EXPERIMENT , 2001 .

[16]  Mehdi R. Khorrami,et al.  Computational aeroacoustic analysis of slat trailing-edge flow , 1999 .

[17]  Yueping Guo.  A discrete vortex model for slat noise prediction , 2001 .

[18]  Thomas F. Brooks,et al.  Flap Edge Aeroacoustic Measurements and Predictions , 2000 .