Computational Investigation of Blade–Vortex Interaction of Coaxial Rotors for eVTOL Vehicles

Ziyi Xu, Min Chang (), Junqiang Bai and Bo Wang
Additional contact information
Ziyi Xu: School of Aeronautics, Northwestern Polytechnical University, Xi’an 710060, China
Min Chang: Unmanned System Research Institute, Northwestern Polytechnical University, Xi’an 710060, China
Junqiang Bai: Unmanned System Research Institute, Northwestern Polytechnical University, Xi’an 710060, China
Bo Wang: UAV Lab of Institute of Engineering Thermophysics (IET), Beijing 100190, China

Energies, 2022, vol. 15, issue 20, 1-13

Abstract: In the design of electric vertical takeoff and landing (eVTOL) vehicles, coaxial rotors have garnered significant attention due to their superior space usage and aerodynamic efficiency compared to standard rotors. However, it is challenging to study the flow field near the rotors due to the blade–vortex interface (BVI) and vortex–vortex contact between two rotors. Using sliding mesh technology and Reynolds-averaged Navier–Stokes (RANS) solvers, a numerical method was established to simulate the flow field of a coaxial rotor in hover, which was verified by experiments. Using this method, this paper analyzes the relationship between position and intensity of the tip vortex of the upper rotor, the axial velocity of induced flow and the load distribution on the blades at the azimuth when the BVI phenomenon occurs with a difference in rotational speed and rotor spacing. The results indicate that, when the BVI phenomenon appears, the blade-tip vortex of the top rotor rapidly dissipates, and the load distribution of the lower blade changes due to the induced flow of the vortex. When the rotational speed increases, the spanwise thrust coefficient of each rotor changes slightly. The vortex–vortex interaction becomes stronger, which leads to vortex pairing. When the distance between the rotors decreases, the BVI phenomenon occurs at an earlier azimuth and the location of the BVI moves towards the tip of the lower blade. The vortex–vortex interaction is also enhanced, which leads to vortex pairing and vortex merging.

Keywords: eVTOL; coaxial rigid rotors; hover; unsteady flow field; BVI; load distribution (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2022
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/15/20/7761/pdf (application/pdf)
https://www.mdpi.com/1996-1073/15/20/7761/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:15:y:2022:i:20:p:7761-:d:948404

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().