E.J. Kerschen, R.A. Reba

A theoretical analysis is presented for control of wake-airfoil interaction noise by the use of actuators on the airfoil surfaces near the leading edge. The objective is to eliminate the sound radiation by cancelling the wake-airfoil noise near its source (the leading edge) Actuators are mounted on the upper and lower surfaces of the airfoil and driven out of phase, to match the anti-symmetric nature of the wake-airfoil noise field. For a specified actuator size and location (relative to the leading edge), the analysis determines the actuator amplitude and phase which minimizes the total sound radiation. The cancellation is most effective when the directivity pattern for the control field closely matches that for the wake-airfoil noise field. At low Machnumbers, this is achieved by mounting the actuators sufficiently close to the leading edge. At high subsonic Mach numbers, the sound cancellation that can be achieved with a single actuator on each surface is limited by mismatch in the directivity patterns. However, an excellent match in directivity patterns can be recovered with the use of two actuators on each surface, leading to effective control of the wake-airfoil interaction noise.

First Joint CEAS/AIAA Aeroacoustics Conference, München, 1995

Conference Paper

englisch

21,0 x 29,7 cm, 10 Seiten

DGLR-Bericht, 1995, 1995-01, First Joint CEAS/AIAA Aeroacoustics Conference - Proceedings; S.435-444; 1995; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics

Bibliothek

1995