Measurements of aerodynamic derivatives on a wing with a series of tip bodies

Abstract

Oscillatory aerodynamic lift and pitching-moment derivatives have been measured in a wind tunnel at low subsonic speeds on the following wing and wing-body combinations: (i) tapered wing of aspect ratio 1.3, mid-chord line unswept, with a sharp leading edge, (ii) above wing fitted with a nacelle in three chordwise positions at the tip, (iii) wing at (i) fitted with a tip body representing a tank or store, and tested with and without a fin at the rear of the body. The measured derivatives for the wing alone are in good agreement with values calculated using lifting-surface theory, and are in reasonable agreement with values calculated using a semi-empirical method. Derivatives for the wing with nacelle in the central position have been calculated using a semi-empirical method which makes an allowance for aerodynamic interference effects, and comparison shows that the values are reasonably accurate.