Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight

Hyo Wan Kim, Adam R. Kenyon, Karthikeyan Duraisamy, R.E. Brown

Research output: Contribution to conferencePaper

Abstract

The aerodynamic and acoustic characteristics of a generic hingeless coaxial helicopter with a tail-mounted propulsor and stabiliser have been simulated using Brown's Vorticity Transport Model. This has been done to investigate the ability of models of this type to capture the aerodynamic interactions that are generated between the various components of realistic, complex helicopter configurations. Simulations reveal the aerodynamic environment of the coaxial main rotor of the configuration to be dominated by internal interactions that lead to high vibration and noise. The wake of the main rotor is predicted to interact strongly with the tailplane, particularly at low forward speed, to produce a strong nose-up pitching moment that must be countered by significant longitudinal cyclic input to the main rotor. The wake from the main rotor is ingested directly into the tail propulsor over a broad range of forward speeds, where it produces significant vibratory excitation of the system as well as broadband noise. The numerical calculations also suggest the possibility that poor scheduling of the partition of the propulsive force between the main rotor and propulsor as a function of forward speed may yield a situation where the propulsor produces little thrust but high vibration as a result of this interaction. Although many of the predicted effects might be ameliorated or eliminated entirely by more careful or considered design, the model captures many of the aerodynamic interactions, and the resultant effects on the loading on the system, that might be expected to characterise the dynamics of such a vehicle. It is suggested that the use of such numerical techniques might eventually allow the various aeromechanical problems that often beset new designs to be circumvented - hopefully well before they manifest on the prototype or production aircraft.

Conference

Conference9th International Powered Lift Conference, IPLC2008
CityLondon, UK
Period22/07/0824/07/08

Fingerprint

Coaxial
Helicopter
Propellers
Helicopters
Aerodynamics
Rotor
Acoustics
Rotors
Interaction
Wake
Tail
Vibration
Configuration
Numerical Techniques
Vorticity
Numerical Calculation
Broadband
Aircraft
Excitation
Scheduling

Keywords

  • hingeless coaxial helicopter
  • tail-mounted propulsor and stabiliser
  • vorticity transport model
  • aerodynamic interactions
  • vibration and noise

Cite this

Kim, H. W., Kenyon, A. R., Duraisamy, K., & Brown, R. E. (2008). Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight. Paper presented at 9th International Powered Lift Conference, IPLC2008, London, UK, .
Kim, Hyo Wan ; Kenyon, Adam R. ; Duraisamy, Karthikeyan ; Brown, R.E. / Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight. Paper presented at 9th International Powered Lift Conference, IPLC2008, London, UK, .
@conference{29f736de9918422e97cab73064bb9540,
title = "Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight",
abstract = "The aerodynamic and acoustic characteristics of a generic hingeless coaxial helicopter with a tail-mounted propulsor and stabiliser have been simulated using Brown's Vorticity Transport Model. This has been done to investigate the ability of models of this type to capture the aerodynamic interactions that are generated between the various components of realistic, complex helicopter configurations. Simulations reveal the aerodynamic environment of the coaxial main rotor of the configuration to be dominated by internal interactions that lead to high vibration and noise. The wake of the main rotor is predicted to interact strongly with the tailplane, particularly at low forward speed, to produce a strong nose-up pitching moment that must be countered by significant longitudinal cyclic input to the main rotor. The wake from the main rotor is ingested directly into the tail propulsor over a broad range of forward speeds, where it produces significant vibratory excitation of the system as well as broadband noise. The numerical calculations also suggest the possibility that poor scheduling of the partition of the propulsive force between the main rotor and propulsor as a function of forward speed may yield a situation where the propulsor produces little thrust but high vibration as a result of this interaction. Although many of the predicted effects might be ameliorated or eliminated entirely by more careful or considered design, the model captures many of the aerodynamic interactions, and the resultant effects on the loading on the system, that might be expected to characterise the dynamics of such a vehicle. It is suggested that the use of such numerical techniques might eventually allow the various aeromechanical problems that often beset new designs to be circumvented - hopefully well before they manifest on the prototype or production aircraft.",
keywords = "hingeless coaxial helicopter, tail-mounted propulsor and stabiliser, vorticity transport model, aerodynamic interactions, vibration and noise",
author = "Kim, {Hyo Wan} and Kenyon, {Adam R.} and Karthikeyan Duraisamy and R.E. Brown",
note = "Awarded best paper in conference. Also published in: Aeronautical Journal (2009), 113 (1140), pp65-78. This is a variant record V of: 27535; 9th International Powered Lift Conference, IPLC2008 ; Conference date: 22-07-2008 Through 24-07-2008",
year = "2008",
month = "7",
day = "22",
language = "English",

}

Kim, HW, Kenyon, AR, Duraisamy, K & Brown, RE 2008, 'Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight' Paper presented at 9th International Powered Lift Conference, IPLC2008, London, UK, 22/07/08 - 24/07/08, .

Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight. / Kim, Hyo Wan; Kenyon, Adam R.; Duraisamy, Karthikeyan; Brown, R.E.

2008. Paper presented at 9th International Powered Lift Conference, IPLC2008, London, UK, .

Research output: Contribution to conferencePaper

TY - CONF

T1 - Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight

AU - Kim, Hyo Wan

AU - Kenyon, Adam R.

AU - Duraisamy, Karthikeyan

AU - Brown, R.E.

N1 - Awarded best paper in conference. Also published in: Aeronautical Journal (2009), 113 (1140), pp65-78. This is a variant record V of: 27535

PY - 2008/7/22

Y1 - 2008/7/22

N2 - The aerodynamic and acoustic characteristics of a generic hingeless coaxial helicopter with a tail-mounted propulsor and stabiliser have been simulated using Brown's Vorticity Transport Model. This has been done to investigate the ability of models of this type to capture the aerodynamic interactions that are generated between the various components of realistic, complex helicopter configurations. Simulations reveal the aerodynamic environment of the coaxial main rotor of the configuration to be dominated by internal interactions that lead to high vibration and noise. The wake of the main rotor is predicted to interact strongly with the tailplane, particularly at low forward speed, to produce a strong nose-up pitching moment that must be countered by significant longitudinal cyclic input to the main rotor. The wake from the main rotor is ingested directly into the tail propulsor over a broad range of forward speeds, where it produces significant vibratory excitation of the system as well as broadband noise. The numerical calculations also suggest the possibility that poor scheduling of the partition of the propulsive force between the main rotor and propulsor as a function of forward speed may yield a situation where the propulsor produces little thrust but high vibration as a result of this interaction. Although many of the predicted effects might be ameliorated or eliminated entirely by more careful or considered design, the model captures many of the aerodynamic interactions, and the resultant effects on the loading on the system, that might be expected to characterise the dynamics of such a vehicle. It is suggested that the use of such numerical techniques might eventually allow the various aeromechanical problems that often beset new designs to be circumvented - hopefully well before they manifest on the prototype or production aircraft.

AB - The aerodynamic and acoustic characteristics of a generic hingeless coaxial helicopter with a tail-mounted propulsor and stabiliser have been simulated using Brown's Vorticity Transport Model. This has been done to investigate the ability of models of this type to capture the aerodynamic interactions that are generated between the various components of realistic, complex helicopter configurations. Simulations reveal the aerodynamic environment of the coaxial main rotor of the configuration to be dominated by internal interactions that lead to high vibration and noise. The wake of the main rotor is predicted to interact strongly with the tailplane, particularly at low forward speed, to produce a strong nose-up pitching moment that must be countered by significant longitudinal cyclic input to the main rotor. The wake from the main rotor is ingested directly into the tail propulsor over a broad range of forward speeds, where it produces significant vibratory excitation of the system as well as broadband noise. The numerical calculations also suggest the possibility that poor scheduling of the partition of the propulsive force between the main rotor and propulsor as a function of forward speed may yield a situation where the propulsor produces little thrust but high vibration as a result of this interaction. Although many of the predicted effects might be ameliorated or eliminated entirely by more careful or considered design, the model captures many of the aerodynamic interactions, and the resultant effects on the loading on the system, that might be expected to characterise the dynamics of such a vehicle. It is suggested that the use of such numerical techniques might eventually allow the various aeromechanical problems that often beset new designs to be circumvented - hopefully well before they manifest on the prototype or production aircraft.

KW - hingeless coaxial helicopter

KW - tail-mounted propulsor and stabiliser

KW - vorticity transport model

KW - aerodynamic interactions

KW - vibration and noise

UR - http://www.raes.org.uk/conference/PDFs/566.pdf

UR - http://strathprints.strath.ac.uk/27535/

M3 - Paper

ER -

Kim HW, Kenyon AR, Duraisamy K, Brown RE. Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight. 2008. Paper presented at 9th International Powered Lift Conference, IPLC2008, London, UK, .