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The Application of a Lifting-Surface Method to Large, Steady or Oscillating Models in Subsonic, Closed, Open or Slotted Wind Tunnels

Published online by Cambridge University Press:  07 June 2016

R A Streather
R A Streather*
Affiliation:
Aeronautics Research Unit, CSIR, Pretoria, formerly University of Natal, Durban
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Summary

A subsonic, lifting-surface method is extended to apply to low-frequency oscillations of wind-tunnel models, taking into account both longitudinal and lateral variations of tunnel lift interference. Rectangular sectioned tunnels with closed, slotted or open roof and floor and closed sidewalls are considered. A comparison is made between the aerodynamic derivatives obtained by this method and those calculated with the assumption that the model span is small compared to the tunnel width. Three models of aspect ratio 2.67 and different sweepback are considered in rigid pitching oscillations in tunnels of width/height ratio 2.5. The greatest differences between the results from the two methods occur for the tunnel with closed roof and floor and for the unswept planform. The least differences occur for the slotted tunnel and for the planform of greatest sweepback. The results indicate that, for models of conventional size [up to span/(tunnel width) ratio of 0.4], the “small-span” assumption is satisfactory in tunnels with slotted roof and floor and closed side walls, but not in fully closed tunnels.

Type
Research Article
Information
Aeronautical Quarterly , Volume 26 , Issue 1 , February 1975 , pp. 41 - 55
Copyright
Copyright © Royal Aeronautical Society. 1975

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References

1 Garner, H C Moore, A W Wight, M K C The theory of interference effects on dynamic measurements in slotted-wall tunnels at subsonic speeds and comparisons with experiment. ARC R & 3500, 1968. (Formerly NPL Aero Report 1211, 1966.)Google Scholar
2 Garner, H C Theoretical use of variable porosity in slotted tunnels for minimising wall interference on dynamic measurements. RAE Technical Report 71017, 1971.Google Scholar
3 Streather, R A A new method for the evaluation of slotted wind tunnel interference parameters applicable to subsonic oscillatory tests. Journal of the Royal Aeronautical Society, Vol 76, pp 443–447, July 1972.Google Scholar
4 Woodcock, D C A comparison of methods used in lifting-surface theory. (Supplement to the Manual on Aeroelasticity.) AGARD Report 583, 1971.Google Scholar
5 Watkins, C E Woolston, D S Cunningham, H J A systematic kernel function procedure for determining aerodynamic forces on oscillating or steady finite wings at subsonic speeds. NASA TR R-48, 1959.Google Scholar
6 Watkins, C E Runyan, H.L. Woolston, D S On the kernel function of the integral equation relating the lift and downwash distributions of oscillating finite wings in subsonic flow. NACA Report 1234, 1955.Google Scholar
7 Rushton, K R Tomlinson, Lucy M Numerical solutions of oscillatory lift interference. Parti. Oscillatory lift inter-ference in low-speed rectangular tunnels with porous-slotted roof and floor. ARC R& M 3700, 1971.Google Scholar
8 Miles, C J W Bridgman, K B Measurements of the direct pitching oscillation derivatives for three cropped delta and three arrowhead planforms at subsonic and transonic speeds. ARCR & M 3397, 1962.Google Scholar
9 Streather, R A Ventilated wall interference on large wind-tunnel models in oscillatory motion. Thesis submitted for the degree of Doctor of Philosophy, University of Southampton, 1969.Google Scholar