View in EDS PDF Full Text

Quantification of the Ground Effect on the Aerodynamic Interferences of a Coaxial Rotor System.

Saved in:
Bibliographic Details
Title: Quantification of the Ground Effect on the Aerodynamic Interferences of a Coaxial Rotor System.
Authors: Moore, Zachary1, Silwal, Lokesh2, Vijayaraj, Aditya1, Raghav, Vrishank3
Source: Journal of the American Helicopter Society. Jan2026, Vol. 71 Issue 1, p1-13. 13p.
Subjects: Rotor dynamics, Rotors, Applied sciences, Rotorcraft, Momentum (Mechanics), Aerodynamics
Abstract: The aerodynamic interactions of a counterrotating coaxial rotor (CCR) hovering in-ground effect (IGE) were investigated using a mechanically decoupled two-bladed rotor facility. A momentum theory-based theoretical framework was developed to quantify the aerodynamic interactions. Baseline measurements were performed on a single rotor out-of-ground effect (OGE) and IGE, and a coaxial rotor OGE. Then, coaxial rotor IGE measurements were conducted to evaluate the competing rotor-rotor and rotor-ground interactions. The coaxial rotor experienced rotor-ground interactions similar to a single rotor at multiple IGE conditions. At the most extreme IGE condition studied, the rotor-ground interaction reduced the required power of the CCR by roughly 30%. However, changes in the rotor-rotor interactions at this condition significantly altered the performance of the upper and lower rotors, with the lower rotor necessitating 8% more induced power while the upper rotor required 8% less power when compared to the respective performance characteristics of OGE. Flow field measurements indicated that the wake of the upper rotor contracts less in the presence of the ground, which exacerbates the negative performance effect on the lower rotor. [ABSTRACT FROM AUTHOR]
Copyright of Journal of the American Helicopter Society is the property of American Helicopter Society dba Vertical Flight Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Links:
  – Type: pdflink
Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 191907083
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Quantification of the Ground Effect on the Aerodynamic Interferences of a Coaxial Rotor System.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Moore%2C+Zachary%22">Moore, Zachary</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Silwal%2C+Lokesh%22">Silwal, Lokesh</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Vijayaraj%2C+Aditya%22">Vijayaraj, Aditya</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Raghav%2C+Vrishank%22">Raghav, Vrishank</searchLink><relatesTo>3</relatesTo>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+the+American+Helicopter+Society%22">Journal of the American Helicopter Society</searchLink>. Jan2026, Vol. 71 Issue 1, p1-13. 13p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Rotor+dynamics%22">Rotor dynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Rotors%22">Rotors</searchLink><br /><searchLink fieldCode="DE" term="%22Applied+sciences%22">Applied sciences</searchLink><br /><searchLink fieldCode="DE" term="%22Rotorcraft%22">Rotorcraft</searchLink><br /><searchLink fieldCode="DE" term="%22Momentum+%28Mechanics%29%22">Momentum (Mechanics)</searchLink><br /><searchLink fieldCode="DE" term="%22Aerodynamics%22">Aerodynamics</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: The aerodynamic interactions of a counterrotating coaxial rotor (CCR) hovering in-ground effect (IGE) were investigated using a mechanically decoupled two-bladed rotor facility. A momentum theory-based theoretical framework was developed to quantify the aerodynamic interactions. Baseline measurements were performed on a single rotor out-of-ground effect (OGE) and IGE, and a coaxial rotor OGE. Then, coaxial rotor IGE measurements were conducted to evaluate the competing rotor-rotor and rotor-ground interactions. The coaxial rotor experienced rotor-ground interactions similar to a single rotor at multiple IGE conditions. At the most extreme IGE condition studied, the rotor-ground interaction reduced the required power of the CCR by roughly 30%. However, changes in the rotor-rotor interactions at this condition significantly altered the performance of the upper and lower rotors, with the lower rotor necessitating 8% more induced power while the upper rotor required 8% less power when compared to the respective performance characteristics of OGE. Flow field measurements indicated that the wake of the upper rotor contracts less in the presence of the ground, which exacerbates the negative performance effect on the lower rotor. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of the American Helicopter Society is the property of American Helicopter Society dba Vertical Flight Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=191907083
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.4050/JAHS.71.012005
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 13
        StartPage: 1
    Subjects:
      – SubjectFull: Rotor dynamics
        Type: general
      – SubjectFull: Rotors
        Type: general
      – SubjectFull: Applied sciences
        Type: general
      – SubjectFull: Rotorcraft
        Type: general
      – SubjectFull: Momentum (Mechanics)
        Type: general
      – SubjectFull: Aerodynamics
        Type: general
    Titles:
      – TitleFull: Quantification of the Ground Effect on the Aerodynamic Interferences of a Coaxial Rotor System.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Moore, Zachary
      – PersonEntity:
          Name:
            NameFull: Silwal, Lokesh
      – PersonEntity:
          Name:
            NameFull: Vijayaraj, Aditya
      – PersonEntity:
          Name:
            NameFull: Raghav, Vrishank
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 01
              Text: Jan2026
              Type: published
              Y: 2026
          Identifiers:
            – Type: issn-print
              Value: 00028711
          Numbering:
            – Type: volume
              Value: 71
            – Type: issue
              Value: 1
          Titles:
            – TitleFull: Journal of the American Helicopter Society
              Type: main
ResultId 1