Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-22T11:42:54.296Z Has data issue: false hasContentIssue false

An investigation of a hovering rotor in ground effect

Published online by Cambridge University Press:  04 July 2016

A. Graber
Affiliation:
Faculty of Aerospace Engineering, Technion, Israel
A. Rosen
Affiliation:
Faculty of Aerospace Engineering, Technion, Israel
A. Seginer
Affiliation:
Faculty of Aerospace Engineering, Technion, Israel

Abstract

A new free-wake aerodynamic model of a rotor hovering in ground effect is briefly presented. The numerical characteristics of the model are investigated. The convergence between consecutive iterations and convergence with respect to different parameters that define the model, are presented and discussed. The model is then validated by comparing the numerical results with existing experimental data. Very good agreement of the thrust coefficient is obtained, whereas discrepancies in the torque coefficients are discussed. At the end of the paper the capabilities of the model are shown by considering various aspects of the ground effect.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1991 

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. Knight, M. and Hefner, R. A. Analysis of Ground Effect on the Lifting Airscrew, 1941, NASA TN-835.Google Scholar
2. Zbrozek, J. Ground Effect on Lifting Rotors, 1950, ARC R&M No. 2347.Google Scholar
3. Cheeseman, I. C. and Bennett, W. E. The Effect of the Ground on a Helicoptor Rotor in Forward Flight, 1957, ARC R&M No. 3021.Google Scholar
4. Koo, J. and Oka, T. Experimental Study on the Ground Effect of a Model Helicopter Rotor in Hovering, 1971, NASA TT-F-13938.Google Scholar
5. Fradenburgh, E. A. The helicopter and the ground effect machine, J Am Helicopter Soc, 1960, 5, (4), pp 2433.Google Scholar
6. Sharpe, D. L. An Experimental Investigation of the Flap-Lag-Torsion Aeroelastic Stability of a Small-Scale Hingeless Helicopter Rotor in Hover, 1986, NASA TP-2546, AVSCOM Tech. Report 85-A-9.Google Scholar
7. Betz, A. The Ground Effect on Lifting Propellers, 1937, NACA TM836.Google Scholar
8. Duwaldt, F. A. Wakes of Lifting Propellers (Rotors) in Ground Effect, 1966, Cornell Aeronautical Laboratory, Inc., Buffalo, NY CAL Report No. BB-1655-S-3.Google Scholar
9. Saberi, H. A. Analytical Model of Rotor Wake Aerodynamics in Ground Effect, 1983, NASA CR 166533.Google Scholar
10. Rosen, A., Graber, A. and Seginer, A. A Free-Wake Model of a Rotor Hovering in Ground Effect, Faculty of Aerospace Engineering, Technion, Israel.Google Scholar
11. Langrebe, A. J. An Analytical and Experimental Investigation of Helicopter Rotor Hover Performance and Wake Geometry Characteristics, June 1971, USAAMRDL Technical Report 71-24.Google Scholar
12. Scully, M. P. Computation of Helicopter Rotor Wake Geometry and Its Influence on Rotor Harmonic Airloads, 1975, Ph.D. Thesis, Dept. of Aeronautical Engineering, Massachusetts Institute of Technology, Boston, Massachusetts.Google Scholar
13. Miller, R. H. A simplified approach to the free wake analysis of a hovering rotor, Vertica, 1982, 6, (2), pp 8995.Google Scholar
14. Favierer, D., Nsi Mba, M., Barbi, C. and Maresca, C. A free wake analysis for hovering rotors and advancing propellers, Vertica, 1988, 11, (3), pp 493511.Google Scholar
15. Rosen, A. and Graber, A. Free wake model of hovering rotors having straight or curved blades, J Am Helicopter Soc, 1988, 33, (3), pp 1119.Google Scholar
16. Graber, A. and Rosen, A. A parametric investigation of a free-wake analysis of hovering rotors, Vertica, 1988, 12, (1/2), pp 179196.Google Scholar
17. Saberi, H. A. Private communication, 1985.Google Scholar
18. Graber, A. A Free-Wake Analysis of Rotor in Ground Effect, D.Sc. Thesis, Faculty of Aerospace Eng., Technion-Israel Institute of Technology, Haifa, Israel, March 1990.Google Scholar
19. Stepniewski, W. Z. and Keys, C. N. Rotary-Wing Aerodynamics, Dover Publications Inc., NY, 1984, Vol. 1, pp 316325.Google Scholar
20. Bramwell, A. R. S. Helicopter Dynamics, John Wiley & Sons, NY, 1976, pp 9096.Google Scholar