Acoustic analysis of counter-rotating open rotors with a locked blade row

Smith, D.A. , Filippone, A. and Barakos, G.N. (2020) Acoustic analysis of counter-rotating open rotors with a locked blade row. AIAA Journal, 58(10), pp. 4401-4414. (doi: 10.2514/1.J059273)

Abstract

Counter-rotating open rotors (CRORs) have the potential to reduce environmental emissions thanks to their high propulsive efficiency. However, there are a number of concerns surrounding their acoustic emissions. This contribution presents a novel multiconfiguration CROR that offers considerable noise reductions. In particular, locking either the fore or aft rotor during takeoff is considered, with the running rotor providing the required thrust. During cruise, both rotors are operated to retain the high efficiency of the CROR. A coupled computational fluid dynamics/computational aeroacoustics analysis has shown the potential of this multiconfiguration concept to offer substantial noise reductions when compared to a baseline CROR. During a simulated constant-altitude flyover at takeoff conditions, reductions of 3.5 and 7.9 dBA have been demonstrated when either the fore or aft row is locked, respectively. Using the effective perceived noise level metric, this result corresponded to 7 and 12 Effective Perceived Noise Level (in Decibels), respectively, for the same flyover.

• Item Type: Articles
• Additional Information: This research is supported by a private sponsorship (Mike Newton) and U.K. Research Council grant EP/S010092/1 (Methods and Experiments for Novel Rotorcraft). The authors would like to acknowledge the use of the Cirrus U.K. National Tier-2 High Performance Computing service at EPCC¶ funded by the University of Edinburgh and Engineering and Physical Sciences Research Council (EP/P020267/1).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Barakos, Professor George and Filippone, Dr Antonino and Smith, Dr Dale
• Authors: Smith, D.A., Filippone, A., and Barakos, G.N.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: AIAA Journal
• Publisher: American Institute of Aeronautics and Astronautics, Inc.
• ISSN: 0001-1452
• ISSN (Online): 1533-385X
• Published Online: 01 July 2020
• Copyright Holders: Copyright © 2020 AIAA
• First Published: First published in AIAA Journal 58(10):4401-4414
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher