A Wind-Tunnel Investigation of the Effects of Flap Span and Deflection Angle, Wing Planform and a Body on the High-Lift Performance of a 28 deg Swept Wing.
Abstract
Lift, drag and pitching moment have been measured over an extensive range of configurations of the high-lift system on a wing of basic aspect ratio 8.35 and with a trailing-edge planform extension and a body added. The results were analysed and compared with two linear-theory prediction methods. The measured increments in lift generated by the various elements of the high-lift system were lower than the predicted levels. An exploratory analysis of the drag results showed that the lift-dependent drag factor was considerably underestimated by linear theory, particularly when the slat was deployed. The limitations of the planar vortex sheet used in the theory and the neglect of viscous effects are suggested as the principal reasons for the differences between experiment and theory. Deflection of the flap produced a load, which acted at a distance forward of the mean quarter chord of the flap, that was practically independent of incidence and flap span. The wing/body interference effect was insensitive to flap span and there was some evidence of a download being generated on the rear body when the high-lift system was deployed. The performance of the high-lift system was downgraded when the wing planform was extended in the root region and this was attributed to the greater non-uniformity of the spanwise loading. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1976
- Accession Number
- ADA041720
Entities
People
- D. A. Lovell