Hostname: page-component-848d4c4894-nr4z6 Total loading time: 0 Render date: 2024-05-16T04:10:35.223Z Has data issue: false hasContentIssue false
  • English
  • Français

The Origin and Nature of the Lift Force on the Leeward of Two Bluff Bodies

Published online by Cambridge University Press:  07 June 2016

S J Price
S J Price*
Affiliation:
Central Electricity Research Laboratories, formerly, Bristol University
Get access

Summary

This paper deals with the force coefficients on the leeward of two bluff bodies, in particular with the origin and nature of the lift force. Initially a general description of the characteristics of the force coefficients, plus the effect of parameters such as free-stream turbulence and surface roughness in the form of stranding, is given.

A resume of all the known suggestions for the origin of the lift force is listed and a series of experiments, attempting to test these suggestions using simple methods, is described. These methods consist mainly of force measurement, involving force measurement on the leeward conductor using different shapes for the leeward and windward bodies. However, static pressure tapping and flow visualisation are also employed to a small degree.

It is shown that none of the suggestions gives a satisfactory explanation for the origin of the lift force. However, several interesting points were noted; for instance the dependence of the lift profiles for the leeward body on its own characteristics in the wake and not particularly on the wake characteristics. Hence it is shown that the use of wake parameters, measured without the presence of the leeward body when attempting to assess the forces thereon, is an over-simplification of the situation as far as lift is concerned while appearing to work quite well for drag.

Type
Research Article
Information
Aeronautical Quarterly , Volume 27 , Issue 2 , May 1976 , pp. 154 - 168
Copyright
Copyright © Royal Aeronautical Society. 1976

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 Cooper, K R Wardlaw, R L Aeroelastic instabilities in wakes. Third International Conference on Wind Effects on Buildings and Structures, Tokyo, Japan, September 1971.Google Scholar
2 Savkar, S D Wake-induced oscillations in transmission line bundles. IEEE Summer Power Meeting and EHV Conference, Los Angeles, California, July 1970.Google Scholar
3 Taylor, G I Motion of solids in fluids when the flow is irrotational. Proc. Roy. Soc., A, Vol 93, pp 99–113, 1947.Google Scholar
4 Counihan, J Lift and drag measurements on stranded cables. Imperial College Report 117, 1963.Google Scholar
5 Price, S J Wake-induced flutter of power transmission conductors. Journal of Sound and Vibration, Vol 38(1), pp 125–147, 1975.Google Scholar
6 Simpson, A Price, S J On the use of “damped” and “undamped” quasi-static aerodynamic models in the study of wake-induced flutter. IEEE Power Engineering Society Summer Meeting, Anaheim, California, 1974.Google Scholar
7 Maekawa, T Study on wind pressure against ACSR double conductor. Electrical Engineering in Japan, Vol 84, 1964.Google Scholar
8 Best, M S Cook, N J The forces on a circular cylinder in a shear flow. University of Bristol, Aeronautical Engineering Department, Report 103, 1967.Google Scholar
9 Wardlaw, R L Watts, J A Wind-tunnel and analytical investigations into the aeroelastic behaviour of bundled conductors. IEEE Power Engineering Society Summer Meeting, Anaheim, California, 1974.Google Scholar
10 Calvert, J R Private communication.Google Scholar
11 Mair, W A Maull, D J Aerodynamic behaviour of bodies in the wakes of other bodies. Philosophical Transactions of the Royal Society, A, Vol 269, 1971.Google Scholar
12 Rawlins, C B Discussion on Reference 6.Google Scholar
13 Richardson, M The pressure distribution on a body in a shear flow. Quarterly of Applied Mathematics, Vol 3, 1945.Google Scholar
14 Simpson, A Wake-induced flutter of circular cylinders: Mechanical aspects. Aeronautical Quarterly, Vol XXII, p 101, May 1971.Google Scholar
15 Cooper, K R Wind-tunnel and theoretical investigations into the aerodynamic stability of smooth and stranded twin-bundled power conductors. National Research Council of Canada, Technical Report LTR-LA-115, 1973.Google Scholar
16 Simpson, A Design of a facility for the study of wake-induced flutter. Paper 326, International Symposium for Vibrational Problems in Industry, Keswick, 1973.Google Scholar
17 Fage, A Falkner, V M Further experiments on the flow around a circular cylinder. ARC R & M 1369, 1931.Google Scholar
18 Zdravkovich, A Effect of shroud geometry on the pressure distribution around a circular cylinder. Journal of Sound and Vibration, Vol 20(4), 1972.CrossRefGoogle Scholar
19 Salus, W L Sarkineh, C F Johnson, M D Parks, G A Ikegami, R Theoretical and experimental studies of wind-induced bundled conductor motions. IEEE Power Engineering Society Summer Meeting, Anaheim, California, 1974.Google Scholar
20 Kinns, R Oscillations of an aerofoil in a vortex wake, an application of digital spectral analysis. PhD thesis, Cambridge University, 1971.Google Scholar