Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-06-16T13:57:47.956Z Has data issue: false hasContentIssue false
  • English
  • Français

Autorotation of rectangular plates

Published online by Cambridge University Press:  26 April 2006

B. W. Skews
B. W. Skews
Affiliation:
School of Mechanical Engineering, University of the Witwatersrand, P.O. WITS, 2050 South Africa
Get access Rights & Permissions [Opens in a new window]

Abstract

A series of tests have been conducted on the autorotation of plates of rectangular section and thickness to chord ratios of from 0.1 to 1.0. The major difference from previous work was that the plates spanned the full width of the wind tunnel, i.e. the flow was essentially two-dimensional. The results show major differences from predictions of infinite aspect ratio plates inferred from finite aspect ratio tests as given by Iversen (1979). Moreover, they give excellent correlation with the two-dimensional numerical solution of Lugt (1980) for a 10% thick plate. In contrast to previous results which indicate no autorotation for square cylinders (t/c = 1.0), it is found that autorotation is easily achieved. A new result is that tipspeed ratios are found to be independent of thickness ratio, at approximately the Lugt value over the full range of thickness ratios. Drag coefficients are found to be independent of thickness ratio. There appears to be a critical thickness ratio above and below which the lift coefficients are constant, but are of different magnitude.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 217 , August 1990 , pp. 33 - 40
Copyright
© 1990 Cambridge University Press

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

Bustamante, A. G. & Stone, G. W. 1969 The autorotation characteristics of various shapes for subsonic and hypersonic flows. AIAA paper 69–132.Google Scholar
Glaser, J. C. & Northup, L. L. 1971 Aerodynamic study of autorotating flat plates. Engng Res. Inst., Iowa State Univ. Ames, Rep. ISU-ERI-Ames 71037.
Iversen, J. D. 1969 The Magnus rotor as an aerodynamic decelerator. Proc. Aerodyn. Deceleration Syst. Conf. vol. 2, pp. 385–395. Air Force Flight Test Centre, Edwards AFB, California.
Iversen, J. D. 1979 Autorotating flat-plate wings: the effect of the moment of inertia, geometry and Reynolds number. J. Fluid Mech. 92, 327–348.Google Scholar
Lugt, H. J. 1980 Autorotation of an elliptic cylinder about an axis perpendicular to the flow. J. Fluid Mech. 99, 817–840.Google Scholar
Lugt, H. J. 1983 Autorotation. Ann. Rev. Fluid Mech. 15, 123–147.Google Scholar
Maxwell, J. C. 1890 On a particular case of the descent of a heavy body in a resisting medium. Scientific Papers, p. 115. Cambridge University Press.
Riabouchinsky, D. P. 1935 Thirty years of theoretical and experimental research in fluid mechanics. J. R. Aeronaut. Soc. 39, 282–348, 377–444.Google Scholar
Smith, E. H. 1971 Autorotating wings: an experimental investigation. J. Fluid Mech. 50, 513–534.Google Scholar