Parametric study of aerodynamic performance of equivalent ducted/un-ducted rotors

Zhang, T., Qiao, G., Smith, D.A. , Barakos, G.N. and Kusyumov, A. (2021) Parametric study of aerodynamic performance of equivalent ducted/un-ducted rotors. Aerospace Science and Technology, 117, 106984. (doi: 10.1016/j.ast.2021.106984)

Abstract

This paper presents the performance analysis and a parametric study of equivalent ducted/un-ducted rotors using high-fidelity CFD methods. A model-scale ducted rotor case by NASA was analysed and used as the initial design. An equivalent un-ducted rotor producing the same thrust and power was first derived using the momentum theory. The ducted/un-ducted configurations were later scaled to support a four-rotor vehicle of 6,000 kg using a BEMT model. High-fidelity CFD simulations of the scaled designs were then performed. Far-filed acoustics of the two configurations was also examined using the FW-H equations. Compared to the equivalent open rotor, the ducted rotor had a significantly reduced frontal area and was also able to deliver the desired thrust at lower torque and reduced noise, but the power was higher due to the higher RPM. A parametric study was then performed in hover and in forward flight to study the performance trends subject to variations of tip speed, blade pitch, blade radius, chord, twist, and duct thickness. Kriging surrogate models were constructed to provide an impression of the performance response to the particular design change. Both configurations showed similar responses to most design variables, but the sensitivity was different between configurations and between flight conditions. Detailed analyses of the parametric results are presented to guide ducted rotor designs.

• Item Type: Articles
• Additional Information: The joint sponsorship of the University of Glasgow and the China Scholarship Council is gratefully acknowledged. Dr Dale Smith was funded by the Leonardo Helicopters during this project. During this work, A.K. was supported by the grant FZSU-2020-0021 (No. 075-03-2020-051/3 from 09.06.2020) of the Ministry of Education and Science of the Russian Federation.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Smith, Dr Dale and Barakos, Professor George and Qiao, Mr Geng and Zhang, Mr Tao
• Authors: Zhang, T., Qiao, G., Smith, D.A., Barakos, G.N., and Kusyumov, A.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Aerospace Science and Technology
• Publisher: Elsevier
• ISSN: 1270-9638
• ISSN (Online): 1626-3219
• Published Online: 26 July 2021
• Copyright Holders: Copyright © 2021 Elsevier Masson SAS
• First Published: First published in Aerospace Science and Technology 117: 106984
• Publisher Policy: Reproduced in accordance with the publisher copyright policy