The modeling of the noise emitted by a profile in a turbulent flow by means of unsteady aerodynamic theories
Abstract
Consideration is given to the analysis of the noise emitted by a two-dimensional airfoil in turbulent flow using various unsteady formulations. The one-dimensional transfer functions of Karman and Liepmann and the two-dimensional model of Filotas (1969), which allows a computation in terms of incident wave number, are employed to calculate the airfoil pressure distribution and the radiated noise and lift spectra, assuming the profile behaves as a point dipole and a simple relation between the longitudinal and transverse wave numbers of the incident turbulence. Anechoic chamber measurements of a NACA 0012 airfoil in turbulent flow are found to be in good agreement with the pressure distribution predicted by theory of Filotas in the leading edge region at relatively high frequencies (300-700 Hz) and with noise predictions at frequencies between 100 and 1500 Hz.
- Publication:
-
Revue d'Acoustique
- Pub Date:
- 1979
- Bibcode:
- 1979RvAc...12...10A
- Keywords:
-
- Aerodynamic Noise;
- Aircraft Noise;
- Airfoils;
- Mathematical Models;
- Noise Prediction (Aircraft);
- Unsteady Aerodynamics;
- Pressure Distribution;
- Transfer Functions;
- Turbulent Flow;
- Two Dimensional Models;
- Acoustics