AU737582B1 - A new construction of aircraft's wing - Google Patents

Description

AUSTRALIA

Patent Act 2000 COMPLETE SPECIFICATION STANDART PATENT A NEW CONSTRUCTION OF AIRCRAFT'S WING The following statement is a full description of this invention, including the best method of performing it known to me IP Australia Documents received on: 12 JUN 2001 Batgh No: FIELD OF THE INVENTION The present invention relates to modified construction of aircraft's wing to increase the ratio lift/drag.

BACKGROUND OF THE INVENTION Many investigators tried and try to construct such models of an aircraft's wing with the help of which we can decrease the drag.

Some investigators suggest reducing the drag skin friction with the help of construction of the small longitudinal ribs on the wing's surface in the direction of fluid flow to reduce momentum transport or drag. The riblets can limit random spanwise movements of the streaks and in result to reduce the drag resulting from boundary layer separation, e.g. US Pat.Nos. 5,386,955 to Anthony M.Savill.

So in US Pat. Nos. 4,786,016 to Presz,Jr the troughts like grooves on the wing's surface were considered with convergent passages which have an accelerating effect on the flow withing the troughs. Also converging troughs decrease the suction surface pressures, and thereby tend to increase lift.The main goal of this invention is to constrain spanwise distribution of streaks in the boundary layer and display turbulent motion away from the wall.

In US Pat. Nos. 5,386,955 to Anthony M.Savill the longitudinal projection like ribs of a boundary in the direction of fluid flow relative to the surfave to modify the interaction of a boundary layer with surface is considered. The riblet surfaces are able to reduce skin friction. Such surfaces are less susceptible to damage and they can be formed straightforwardly.

SUMMORY OF THE INVENTION The invention relates to a construction of an aircraft's wing to increase the lift of the aircraft.

The curved wings for flight are an ingenius idea of the 20-th century. Without the curved wings we were not able to fly. Increase df the lift and decrease of the drag is a very important problem of aerodynamics.

To increase the lift additional wings are sometimes used, but it significantly increases the drag at high velocity (at supersonic velocity).

Increasing the lift we can increase the lifted weight; make the aircraft more stable during flight; decrease the running distance for taking off and landing; decrease the velocity for taking off and landing; decrease the drag for high velocities decreasing the wing's curvature that makes the biggest share of the drag.

All this can be done by the present patent which provides a new construction of an aircraft's wing.

We know the following facts the velocity v of an air stream going through the narrowing tunnel will increase; the lift is proportional to v' v' where VA and vu are velocities of the air stream above and under the wing; the graphics of the lift has the form described in figure 1. We see that the lift rapidly goes to zero in the back side of the wing.

We will consider the longitudinal protrusions with the convergent paths towards the trailing edge on the upper and lower surfaces in the back part of the curved aircraft's wing we save the curvatures). It is known that this construction has accelerating effect on the flow withing the passages. Also, converging paths decrease the surface pressure. All these facts will increase lift in result.

We consider the different longitudinal constructions with convergent narrowing passages among the widening projections in the downstream direction which will increase the drag (compare with the above mentioned patents) defined by interraction of the air stream with the projection's surfaces and increase the lift as well. The drag will depend on the aircraft's velocity. The higher velocity the bigger drag. It can make the big problems for high velocities for supersonic velocities).

When the air stream goes along the convergent passages the interaction with the surfaces of the protrusions will increase. The interaction(friction) of the air stream with the surfaces of the protrusions will be the bigger than the bigger the aircraft's velocity.

This problem will be critical for high velocities for supersonic velocoties).

The suggested patent solves this problem by using the longitudinal protrusions automatically altered during flight on the upper and lower surfaces of the curved wing. It is very important that we save the curvatures in the front part of the wings. The heights of the protrusions and widths of the paths between the protrusions are automatically altered during flight for the ratio lift/drag to increase. The best benefit of the altered protrusions is that we can reduce the wing's curvature which makes the biggest part of the drag during flight without losing the lift.

Altered heights of the protrusions and widths of the paths between the protrusions solve this problem because we can automatically use the protrusions or not regulating the ratio of the lift and drag. For instance, we will not use them for high velocity(at supersonic velocity) in this case where the ratio of the lift and the drag is small.

So the height KL (fig.2) of the triangle ABC and the width BA 1 (fig.2) of the path between neighbouring triangles ABC and AIB 1

C

1 can be automatically altered during flight: for example, the higher velocity the smaller the height KL and the bigger AB. For supersonic velocity KL is equal to zero. We can make such constructions that both KL and BA 1 will decrease or the width BA 1 will only increase while the heights will be the same all time when the velocity increases.

A similar construction can be used not only on the upper surface of the wing but also on the lower surface.

The suggested construction of the aircraft's wing will increase velocity of the air stream and the lift in the back side of the wing. For the wide wings the increase of the lift can reach up to 30 percents.

As asoon as the stream's velocity in the back of the wing is higher than the stream's velocity for the usual construction of the wing, the lift for the suggested construction of the aircraft's wing is bigger (fig. 1, the shaded part).

The suggested construction is different from the constructions in the US Pat. Nos.

4,786,016 to Presz,Jr and in the US Pat. Nos. 5,386,955 to Antony M. Savill. In the first one there were considered the ligitudinal grooves on the wing's surface and in the second one there was nothing said about increase of the lift. According to the last one the suggested construction will reduce skin friction and displace the turbulent motion away.

In the drawings: Figure 1 describes the lift of the wing where Y is the longitudinal coordinate.

Figure 2 describes the form of the wing from above. ADC is the left side of the construction. DBC is the right side of the construction. There is the narrowing path between the neighbouring triangles ABC and AIB 1

C

1 in the downstream direction.

Claims (3)

1. A wing for an aircraft, said wing having protrusion on the upper and(or) lower surfaces thereof, said protrusions being shaped as chordwise extending ribs having tri- angular, semicircular or other cross-sectional shapes, the heights of said protrusions on the upper and(or) lower surfaces of the wing increasing in the downstream direction and said protrusions providing airflow paths between which are convergent so as to promote acceleration of the airflow in the downstream direction and wherein the heights of the protrusions are automatically altered during flight according to the velocity of the aircraft so as to increase the lift/drag ratio of the wing.

2. A wing for an aircraft according to claim 1 wherein the widths of the paths be- tween said protrusion on the upper and(or) lower surfaces of said wing decrease in the downstream direction and said widths are automatically altered during flight in response to the velocity of the aircraft so as to increase the lift/drag ratio of the wing.

3. The construction of the aircraft's wing substantially as herein described with refer- ence to the accompanying Figures 1-2. AN APPLICANT DATE MONTH YEAR 7 3 e 2 oo l