ESDU 94031: Increments in aerofoil lift coefficient at zero angle of attack and in maximum lift coefficient due to deployment of a double-slotted or triple-slotted trailing-edge flap, with or without a leading-edge high-lift device, at low speeds.

Abstract:

ESDU 94031 presents an estimation method based on the theory for a thin hinged plate modified using empirical correlation factors to account for the geometry of practical aerofoils and high-lift devices. Some allowance for the effects of chord extension was made by using flap chord ratio and lift coefficients based on aerofoil extended chord but further adjustments were required to adapt to the considerable departure for slotted flaps from the model, possibly involving large chord extensions. The data for aerofoils with trailing-edge flaps deployed from which the methods were developed were extracted from wind-tunnel tests reported in the literature covering a wide range of practical geometries. Fewer data were available for aerofoils with both leading- and trailing-edge devices deployed. The methods apply to Reynolds numbers greater than a million and freestream Mach numbers less than 0.2. The predicted and test data for the lift coefficient increments correlated to within 15 per cent. The use of the methods is illustrated by worked examples. To obtain results for an aerofoil with both leading-edge devices and slotted flaps deployed, ESDU 84026 is used in conjunction with this document and ESDU 94027.

A computer program of the method is included as part of ESDU LiCrA Toolbox apps and ESDUpacs A9931 and B9931 from (ESDU 99031). See the 'Software' tab, above.

Indexed under:

Details:

Data Item ESDU 94031
Format:	PDF with software
Status:	Original, issued 01 Apr 1995 Published in Release 2000-03 (init)
Previous Releases:	None available
ISBN:	978 0 85679 918 1

The Data Item document you have requested is available only to subscribers.

Subscribers login here.
If you are not an ESDU subscriber find out how to subscribe.

This Data Item is complemented by the following software:

Toolbox Apps

Name

Details

Toolbox LiCrA-2D Run

Title

ESDU LiCrA: 2D Lift Curve Aerodynamics for Aerofoils

Version

1.0

Details

LiCrA 2D calculates the maximum lift coefficient, the lift coefficient at zero angle of attack and the lift curve of aerofoil sections with or without high-lift devices deployed at low speeds.

Calculations can be made for the aerofoil when there are no high-lift devices deployed but the prediction of the shape of the non-linear part of the lift curve should be treated with caution because it employs a technique developed for use when high-lift devices are deployed. The method is intended for use only for free-stream Mach numbers up to about 0.25.

Toolbox LiCrA-3D Run

Title

ESDU LiCrA: 3D Lift Curve Aerodynamics for Wings and Wing/Body Combinations

Version

1.0

Details

LiCrA 3D calculates the maximum lift coefficient, the lift coefficient at zero angle of attack and the lift curve of straight-tapered wings with or without high-lift devices deployed at low speeds. The basic wing (no devices deployed) may have camber and twist. The program includes methods that allow for the presence of a fuselage.

For completeness, calculations can be made for the wing when there are no high-lift devices deployed but the prediction of the shape of the non-linear part of the lift curve should be treated with caution because it employs a technique developed for use when high-lift devices are deployed. The method is intended for use only for free-stream Mach numbers up to about 0.25. No allowance is made for ground effect.

If required, it will also calculate the spanwise position of the section of the basic wing that has the peak loading due to angle of attack.