V.M. Kuznetsiv

Prediction evaluation results and their comparisons with the experimental investigation of the efficiency of a number of jet noise reduction techniques are presented. The space noise distribution prediction of turbulent jet parts of different lengths is done. The sound field evaluation is based on the analysis of convective wave equation solutions and on the application of the experimental data on turbulence characteristics in the mixing region. When evaluating the space noise distribution the mixing layer was divided into a number of parts of finite lenghts. The comparison of the predicted noise of the jet part adjacent to the exhaust nozzle and of the part experimentally singled out by a grid screen located in the mixing region normally to the axis is done. The sound field prediction results for turbulent jet parts are used for the jet flow noise evaluation by dividing the mixing regions into separate parts and by evaluating the acoustic radiation intensity of those parts. Applying the results obtained the jet noise reduction efficiency was evaluated for by-pass nozzles at the expence of the "inverted" velocity profile application as well as the efficiency of multi-jet devices used at the nozzle exit plane.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 6 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.761-766; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics

Bibliothek

1992