AWing or the like The object of the invention is an aircraft wing, an aircraft propeller, a helicopter rotor blade, a sail of a sailing ship or other similar device, by means of which energy is either released to, or taken from a passing flow of gas or liquid, such as air.

Various kinds of aircraft wings and propellers, helicopter rotor blades, and a ship's sail that is like the wing of an aircraft are generally known. They operate by exploiting a force, caused by a passing flow of gas (air), which acts in a different direction to that of the relative flow of the gas (air).

The breaking of the so-called sound barrier is a limiting factor common to all of these.

The situation at present is that jet-engine powered aircraft have been built whose speed exceeds the speed of sound. They must pass through the sound barrier, at which point the increase in the resistance of the wing grows more than would be assumed by a mere increase in speed, calculated by formulae valid at subsonic speeds. The wing drags the air along with it (pulls it with it).

The drag phenomenon arises from the wing friction forcing the molecules of air to move in the direction of the movement of the wing.

The molecules adhere to pits in the surface of the wing. Once the wing is moving at supersonic speeds, the forces between the molecules prevent their natural movement vis-à-vis each other. They are forced to collide violently, and consequently they set up a kind of dynamic wall in front of and behind the wing, which strongly retards movement.

The following text describes the object of the invention in terms of an aircraft wing, though the same principle is repeated in other devices.

The invention is described with the aid of the accompanying figures, in which;

Figure 1 shows one example of a wing profile; Figure 2 shows a situation, in which the wing or similar has a saw-tooth surface; Figure 3 shows a diagram of a situation, complying with the characteristic features of the invention and Figure 4 shows the situation at the molecular level at the edges of the wing or similar.

In a construction according to the invention, the flow takes place in such a way that the drag phenomenon does not occur, even above the speed of sound. This is achieved by making the surface of the wing extremely smooth and suitably shaped.

In a wing 1 according to the invention, the leading edge 2 is sharp enough to separate the air (gas) molecules suitably from one another, without essentially causing them to collide with one another. The trailing edge is marked in Figure 1 with the reference number 3 and has a shape that is sharp enough not to cause turbulence.

Figures 2 and 3 show, in a powerfully magnified and diagrammatic form, how the surface of the wing is so smooth that gas molecules cannot cause turbulence by entering pits, characteristic of an uneven wing or similar. Thus, Figure 2 shows a 'saw- tooth' forward-cut surface 4, with dimensions such that air molecule 5 cannot sink into it to any great depth. It can be assumed that, even if the surface saw-tooth cuts were aligned so that the teeth point backwards in relation to the flow, the individual molecules will still act in the manner of a lubricant.

Figure 3 shows a situation according to the previous figure, with round molecules.

Thus, the surface molecules of the wing or similar are marked with the reference number 6 and the air molecules with the number 5. The smoothness of the surface is such that, under the pressure and other conditions on the wing surface, the air molecule can only sink between the surface molecules of the wing to a distance of less that half of its diameter. Under these circumstances, molecules that have adhered individually act as a 'lubricant', as described previously for Figure 2. The rougher the

surface, the deeper the molecules sink into the irregularities, and the sooner the wing begins to drag again, as stated above.

Figure 4 shows diagrammatically a situation, in which the leading edge of the wing or similar is formed of molecules 6 and the trailing edge correspondingly of molecules 6'. Air molecules striking the leading edge are marked with the number 5. Individual molecules striking the leading edge of the wing or similar only act as a 'lubricant'.

Under the conditions described above, the mutual forces of the air molecules exceed the force component acting in the direction of the movement of the wing, allowing the wing to pass through the air with increasing speed, even after exceeding the speed of sound, until the force component in the direction of the movement of the wing exceeds the value of the mutual cohesive force of the molecules caused by the wing friction, when the air molecules begin to move along the wing and the wing enters a state similar to a traditional wing exceeding the sound barrier and begins to drag air with it.

The leading edge of the wing, its smoothness, and overall profile and angle of attack 7 (Figure 1) determine when the situation described above typical of passing the sound barrier is reached again as speed increases. The angle of attack affects, among other things, the force with which gas molecules strike the wing surface.

When the device is adapted as a propeller, its proportions and speeds are suitably dimensioned so that the exit section of the gap between the propeller, the nose and the fuselage conforms to the above construction. In a propeller used without a nose section, care should be taken to ensure that the propeller meets the above requirements over that part of its length where the speed may reach that of sound.

Naturally, the device will function in a liquid, such as water, in addition to functioning in the gas described above.

Naturally, the same concept can also be applied to increasingly small particles, as the technology develops.