DE29817545U1 - Combined split and arch flap - Google Patents

Description

Description

Combined slotted and cambered flap.
5

Flap profiles have become popular in glider construction because they are characterized by extremely low drag in both fast and slow flight. This is achieved by changing the curvature of the respective laminar profile by moving the flap up or down without disturbing the largely laminar (very low drag) flow.

When implementing the flaps, care must be taken to ensure that no slots are created through which pressure equalization between the lower and upper sides of the wing profile can take place.

Slotted flaps are very effective lift aids, as the upper side of the flap is additionally flowed around by a gap from the underside of the wing - on which there is excess pressure - and thus flow separation is prevented even with larger flap deflections.

The invention is based on the problem of being able to use the flap as an effective lift aid, e.g. for landing approaches or circling in weak thermals.

This problem is solved by the characterizing features of claim 1. 20

The advantages achieved with the invention are in particular that a high lift coefficient is now available for landing approaches or circling in weak thermals, even with a fully functional flap.

In particular, the use of flaps on ultralight aircraft with a prescribed minimum speed is facilitated.

An embodiment of the invention is shown in the following drawings and is described in more detail below. They show

Fig. 1 Flap deflection 35°

The flap (1) is fully extended and generates maximum lift. The deflection of the elastic vane (2) - here: 2 mm upwards - must be taken into account when designing the gap. The approximate flow path is shown with arrows. The transition between the elastic vane (2) and the end box wing (4) is designed to be aerodynamically efficient with a molded part (3) made of rigid foam.

Fig. 2 Flap deflection 10°

In this position, the flap (1) presses against the vane (2) and thus seals the upper side of the wing against the lower side.

All flap positions have a common pivot point, so that the flap (1) can be hinged with a single joint.

Fig. 3 Flap deflection -10°

This configuration is used for high-speed flight. The flap (1) deforms the elastic vane (2) and the molded part (3).

The flap therefore functions as a cambered flap from -10° to 10° flap deflection (no pressure equalization between the bottom and top of the flap).

Claims (3)

Protection claims 1. Combined slotted and cambered flap, characterized in that a slotted flap (or Fowler flap) presss against an elastic vane in a certain area of the flap deflection and thus seals and prevents harmful pressure equalization between the upper and lower sides of the wing, which gives the function as a cambered flap. 2. Combined slotted and cambered flap according to claim 1, characterized in that the vane has a high elasticity parallel to the trailing edge of the wing in order to avoid the formation of waves when the wing bends. This is achieved by means of a laminate with a high proportion of the fiber direction transverse to the trailing edge of the wing. 3. Combined slotted and curved flap according to claim 1, characterized in that the elastic flag is covered on the underside with a sealing material (felt, velvet) in order to improve the sealing and to prevent scratches on the flap.