Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-06-19T16:10:14.143Z Has data issue: false hasContentIssue false
  • English
  • Français

A dimensionality reduction approach in helicopter level flight performance testing

Part of: The AJ Special Rotorcraft Collection

Published online by Cambridge University Press:  13 July 2023

I. Arush Open the ORCID record for I. Arush [Opens in a new window] ,
M.D. Pavel Open the ORCID record for M.D. Pavel [Opens in a new window]  and
M. Mulder Open the ORCID record for M. Mulder [Opens in a new window]
I. Arush*
Affiliation:
National Test Pilot School, Mojave, CA, 93502, USA
M.D. Pavel
Affiliation:
Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands
M. Mulder
Affiliation:
Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands
*
Corresponding author: I. Arush; Email: iarush@ntps.edu
Get access Rights & Permissions [Opens in a new window]

Abstract

Evaluation of the power required in level flight is essential to any new or modified helicopter performance flight-testing effort. The conventional flight-test method is based on an overly simplification of the induced and profile power components required for a helicopter in level flight. This simplistic approach incorporates several drawbacks that not only make execution of flight sorties inefficient and time consuming, but also compromise the level of accuracy achieved. This paper proposes an alternative flight-test method for evaluating the level-flight performance of a conventional helicopter while addressing and rectifying all identified deficiencies of the conventional method. The proposed method, referred to as the corrected-variables screening using dimensionality reduction (CVSDR), uses an original list of 36 corrected variables derived from basic dimensional analysis principles. This list of 36 corrected variables is reduced using tools of dimensionality reduction to keep only the most effective level-flight predictors. The CVSDR method is demonstrated and tested in this paper using flight-test data from a MBB BO-105 helicopter. It is shown that the CVSDR method predicts the power required for level flight about 21% more accurately than the conventional method while reducing the required flight time by an estimate of at least 60%. Unlike the conventional method, the CVSDR is not bounded by the high-speed approximation associated with the induced power estimation, therefore it is also relevant to the low airspeed regime. This low-airspeed relevancy allows the CVSDR method to bridge between the level-flight regime and the hover. Although demonstrated in this paper for a specific type of helicopter, the CVSDR method is applicable for level-flight performance flight testing of any type of conventional helicopter.

Keywords

Helicopter PerformanceLevel-FlightSVDCVSDRDimensional Analysis
Type
Research Article
Information
The Aeronautical Journal , Volume 128 , Issue 1320 , February 2024 , pp. 398 - 427
Check for updates
Copyright
© The Author(s), 2023. Published by Cambridge University Press on behalf of Royal Aeronautical Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Porterfield, J.D., and Alexander, W.T. Measurements and evaluation of helicopter flight loads spectra data, J. Amer. Helicop. Soc., July 1970, 15, (3), pp 22–34(13).CrossRefGoogle Scholar
U.S. Department of Transportation, Federal Aviation Administration, Certification of Normal Category Rotorcraft, AC 27-1B, Change 3, Subpart C, Strength Requirements, AC 27.571, September 2008.Google Scholar
Leishman, J.G. Principles of Helicopter Aerodynamics, 2nd ed., Cambridge University Press, 2006, Chap. 5.Google Scholar
Prouty, R.W. Helicopter Performance Stability and Control, Krieger Publishing Company Malabar Florida, 1989, Chap. 4.Google Scholar
U.S. Naval Test Pilot School, Flight Test Manual, USNTPS-FTM-No. 106, Rotary Wing Performance, Naval Air Warfare Center, Patuxent River, Maryland, 31 December 1996, Chapter 7.Google Scholar
Cooke, A.K. and Fitzpatrick, E.W.H. Helicopter Test and Evaluation, 1st ed., AIAA Education Series, 2002, Chap. 3.Google Scholar
Stepniewski, W.Z. and Keys, C.N. Rotary Wing Aerodynamics, Two Volumes Bounded as One, Dover Publication, Inc., New York, 1984, Chap. 3.Google Scholar
Nagata, J.I., Piotrowski, J.L., Young, C.J., et al. Baseline Performance Verification of the 12th Year Production UH-60A Black Hawk Helicopter. Final Report, US Army Aviation Engineering Flight Activity, Edwards AFB, California, USA, January 1989.Google Scholar
Buckanin, R.M., Kelly, W.A., Webre, J.L., et al. Level Flight Performance Evaluation of the UH-60A Helicopter with the Production External Stores Support System and Ferry Tanks Installed. Final Report, US Army Aviation Engineering Flight Activity, Edwards AFB, California, USA, September 1986.Google Scholar
Belte, D. and Stratton, M.V. Fuel conservation evaluation of U.S. Army helicopters, Part 4, OH-58C flight testing, Final Report, US Army Aviation Engineering Flight Activity, Edwards AFB, California, USA, August 1982.CrossRefGoogle Scholar
Boirun, B.H. Generalizing Helicopter Flight Test Performance Data (GENFLT), The 34th Annual National Forum of the American Helicopter Society, May 1978.10.4050/JAHS.24.51CrossRefGoogle Scholar
Arush, I. and Pavel, M.D. Helicopter gas turbine engine performance analysis: A multivariable approach, Proc. Inst. Mech. Eng. G: J. Aerosp. Eng., 2017; 223, pp 837–850. https://doi.org/10.1177/0954410017741329 Google Scholar
Arush, I., Pavel, M.D. and Mulder, M. A singular values approach in helicopter gas turbine engine flight testing analysis, Proc. Inst. Mech. Eng. G: J. Aerosp. Eng., April 2020. https://doi.org/10.1177/0954410020920060 CrossRefGoogle Scholar
Arush, I., Pavel, M.D. and Mulder, M. A dimensionality reduction approach in helicopter hover performance flight testing, J. Amer. Helicop. Soc., 2022, 67, (032010). https://doi.org/10.4050/JAHS.67.032010 Google Scholar
Leishman, J.G. Principles of Helicopter Aerodynamics, 2nd ed., Cambridge University Press, 2006, Chap. 6.Google Scholar
Prouty, R.W. Helicopter Performance Stability and Control, Krieger Publishing Company Malabar Florida, 1989, Chap. 3.Google Scholar
Noonan, K.W. and Bingman, G.J. Two-Dimensional Aerodynamic Characteristics of Several Rotorcraft Airfoils at Mach Numbers from 0.35 to 0.9, NASA TM X-73990, Langley Research Center, Virginia, January 1977.Google Scholar
Guttman, I., Wilks, S., and Hunter, J. Introductory Engineering Statistics, 2nd ed., John Wiley & Sons, Inc., New York, 1971, Chap. 10.Google Scholar
Kreyszig, E. Advanced Engineering Mathematics, 3rd ed., John Wiley & Sons, Inc., New York, 1972, Chap. 19.Google Scholar
Buckingham, E. On physically similar systems; illustrations of the use of dimensional equations, Phys. Rev., 1914, IV, (4), pp 345–376, https://doi.org/10.1103/PhysRev.4.345 CrossRefGoogle Scholar
Knowles, P. The Application of Non-dimensional Methods to the Planning of Helicopter Performance Flight Trials and Analysis Results, Aeronautical Research Council ARC CP 927, 1967.Google Scholar
Strang, G. Introduction to Linear Algebra, 4th ed., Thomson Brooks/Cole, Belmont, CA, 2006, Chap. 6Google Scholar
Horn, R.A. and Johnson, C.R. Matrix Analysis, 2nd ed., Cambridge University Press, New York, NY, 2012, Chap. 5Google Scholar