CZ2012240A3 - Power transport aircraft - Google Patents

Abstract

A motorized airliner has engines suspended under a wing at an angle (.eta.) At an angle so that when the level flight is steady, their propulsion force (T) causes an upward motion so that the airplane will fly with the least possible customs resistance. This motorized airliner also has a hull shape with high aerodynamic drag and low aerodynamic drag.

Description

airliner

Technical field

The invention relates to multi-engine transport aircraft. in which the engines are seated under the wing at an angle directed at an oblique upward thrust. This angle is derived from the airplane glide. Therefore, the aircraft can fly with a zero angle of attack wings and fuselage in steady flight mode. that is, with the lowest possible frontal resistance and thus the least fuel consumption. The fuselage of such a flying aircraft can therefore be given a shape with higher resistance to sinking even at very low frontal resistance and further reduce its fuel consumption.

BACKGROUND OF THE INVENTION

Since the very beginning of flying, the essence of "falling" heavier air aircraft referred to as buoyancy, a kind of lifting force. This approach follows the Archimedes Law, when the author lifted the body in water by buoyancy. Similarly, airmen approached in the interpretation of the possibility of flying in balloons and airships, whose filling is warm air or other gas lighter air. In both cases, the buoyancy was hydro- or anaerostatic, exerting a lifting force on the bodies even at rest.

More than a hundred years ago, the Wright brothers had done it. that a motor plane can fly quite well, even if it is heavier air, it was necessary to physically and technically explain the nature of flying. Gradually, several theories have been introduced that allow flying to be explained by the lift of aerodynamic L, since in this case it only affects the aircraft in motion. In all reflections on the essence of flying heavier airplanes, the idea of streamlines, ie lines expressing the direction of air flow along a wing with a certain convex profile, is based.

Most contemporary physics textbooks explain buoyancy at different velocities around the upper and lower surfaces of the wing. Air flows faster along the more convex upper surface. to reach his former neighbor just beyond the trailing edge. Then, according to Bernoulli's law, there must be greater pressure from below on the wing than on the upper. This pressure is the buoyancy of the wing.

Other interpretations also use flow asymmetry around the two surfaces of the wing, but consider Newton's air reaction to the need for more bending of the nozzles as they flow around the upper surface. This buoyancy theory is also professed by one of the largest aviation authorities, NASA. On their pages there are very illustrative simulations of how the buoyancy so derived increases unlimitedly with the square of the airplane speed. According to this buoyancy theory, the aircraft takes on such a high speed at take-off that the buoyancy reaches and exceeds the weight of the G plane, which can rise.

In the search for an optimal wing profile, Wright's wind tunnel was already used to test wing sections suspended on a hinge to measure D drag (upstream force) and buoyancy (force perpendicular to the direction of flow) as a function of air velocity . They did so. that the angle of attack is an important parameter of flight mode. It is the angle below which the airplane has an inclined lower flat wing surface. According to the results, wind tunnels show that the buoyancy increases with the angle of attack. Therefore, aircraft take into account this angle in their flight modes. And on a steady level flight, passengers may notice that the airplane is always slightly tilted forward. This tilt is related to the angle of attack and the required buoyancy. Giant. 1 in the annex demonstrates the vector distribution of steady horizontal flight forces according to buoyancy theory.

The buoyancy has gradually become an important attribute not only for explaining the causes of flying, but also for the design of aircraft, the construction of various parts of aircraft, especially wings. One of the first patents to mention is the Wright Brothers USP 821.393, using a buoyancy change by shortening the wing tips and thereby turning and thus controlling the airplane. Since then, thousands of patents have been filed in the US alone, containing a combination of the words "lift plane" and some sort of buoyancy for airplanes. Gradually, a number of buoyancy enhancements have emerged, as higher buoyancy would result in lower power requirements and thus fuel savings.

Several patents related to buoyancy have also been granted in the Czech Republic. While H. Junkers was still concerned with reducing frontal resistance and thus allegedly increasing buoyancy (CPP 14 986), O. Haller had already attempted to increase buoyancy by propeller blowing auxiliary wings (CPP 15 686). Much younger patents include J. Malík. who proposed exhausting air from the wing surface boundary layer (CPC 120 667) and the final idea of J. Sattler, who designed a profile with two or more convex vertices on the upper surface (CPC 295 938) to increase buoyancy.

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However, as the buoyancy increases with greater angles of inclination, the frontal resistance increases and fuel consumption increases. Therefore, usually during take-off and landing choose to use so-called flaps, which increase the floor area of the wings and also activate the wing profile. Tests in the tunnel have confirmed that although such a curved wing profile has a higher frontal resistance, positive buoyancy gain prevails. For a steady part of the flight, the flaps are then retracted and a substantial part of the flight is performed with as little frontal resistance as possible. For airplanes, the characteristic mode is a steady horizontal flight. The airplane is located after 90% of the flight time, the rest are takeoff and landing. In terms of fuel consumption, horizontal flight is therefore the decisive mode.

A major drawback of airplanes constructed in the spirit of buoyancy theory is therefore the need to fly at a positive angle of attack in order to make a steady-state cruise possible at all. Positive angle, however, exposes the entire bottom surface of the wing and fuselage of the air and thus increases the frontal resistance of the aircraft. Increased frontal resistance means increased steady-state fuel consumption.

SUMMARY OF THE INVENTION

These drawbacks and disadvantages are eliminated by a multi-engine aircraft constructed on the basis of a different idea of the essence of flying in still air. Such air has no nozzles around the wing and the entire aircraft. If we imagine a flight of airliner wing in steady horizontal flight mode, the wing enters the still air again and again. It recedes in front of its own elastic compression and therefore with some pressure on the surface of the airplane. After passing the wing and fuselage, the air returns to its original position. It is nowhere to flow and therefore has no streamers.

Therefore, the aircraft does not fly because it has buoyancy provided by the flowing air. It flies because it has a much greater aerodynamic drag resistance than Dg than the forward drag in the direction of flight

D. That is why, in a non-powered flight, it does not fall vertically downwards, but slips to the ground at an angle. In optimal flight mode with maximum glide, the aircraft flies at an angle η. Such a flight mode is characterized by the fact that the aerodynamic frontal resistance at the moment is the least possible.

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If we want to continue the flight horizontally, we have to turn the engines on the wing at an angle η upwards. Then the airplane stops sliding down and flies steady horizontally. And with zero angle of attack and therefore minimal frontal resistance. The vector force distribution is shown in Figure 2. Such a horizontal steady flight will result in fuel savings over airplanes flying at a positive angle of attack.

An important aspect of this nature of the flight is the fact that not only the wing but also the fuselage and the tail are involved in the resistance to the fall of the entire aircraft. The fuselage area of conventional airliners is about a third of the total ground area, so its contribution to overall resistance to decline is relatively significant.

Airliner flight with its engines moving obliquely upwards at an angle η brings yet another advantage. If we give the hull a flat surface or even a concave concave at the bottom, its resistance to sinking can increase significantly. And because the aircraft flies at zero angle of attack, such an aircraft can have a very low frontal resistance. Such an aircraft therefore has less fuel consumption, since its resistance Dg is significantly higher compared to a conventional fuselage of circular or oval shape.

DETAILED DESCRIPTION OF THE INVENTION

In the following examples, η means the angle corresponding to the slip angle in maximum glide mode.

Example

Two or multi-engine transport aircraft of traditional fuselage shapes have engines suspended (fixed or adjustable) under the wing at an angle η so. so that the propulsive forces of the engines point somewhat obliquely upward with a steady level flight. In this flight mode, the aircraft has the lowest possible frontal resistance while flying steady horizontally. Since in this mode, the airplane is flying at zero angle of attack, its frontal resistance is about 4% lower than in the current flight mode with the current usual angle of attack of about 3 °. Fuel savings will also be around 4%.

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Example 2

The multi-engine airliner of Example 1, but having the shape of the fuselage in section according to FIG. 3 The fuselage area of conventional airliners is one-third of the total floor area, excluding the wing-fuselage area. Then, the airplane with the fuselage cross-section of Figure 3 will have a fall resistance coefficient of 29% higher than the airplane of Example 1. The airplane will fly at a zero attack angle, so the flat underside will practically not affect the face resistance at all. Fuel savings will be around 20%.

Example 3

A multi-engine airliner according to Example 1, but having the shape of the fuselage in section according to FIG. A plane with a fuselage of this cross section will have coefficients of resistance to fall by 33% higher fuel savings will be up to 25%.

Example 4

The multi-engine airliner of Example 1, having adjustable flap flaps on the fuselage of FIG. 5. Depending on the flaps size, the airplane will have a drop resistance factor of up to 40% when opened. Fuel savings will therefore be up to 30%.

Example 5

The multi-engine airliner of Example 1, having fixed fuselage longitudinal wings along nearly the entire fuselage of FIG. 6. According to their span, the increase in resistance to falling of the entire airplane will be 15 to 30% higher. Fuel savings will therefore be 10 to 20%.

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Fig. 1 Vector distribution of transport aircraft forces according to the theory of buoyancy during steady horizontal flight

Giant. 2 Vector force distribution of a transport aircraft arranged in accordance with the present invention: in steady horizontal flight according to Example 1

Giant. 3 Hull shape in section according to Example 2

Giant. 4 Hull shape in section according to Example 3

Giant. 5 Hull shape in section according to Example 4

Giant. 6 Hull shape in section according to Example 5

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Claims (2)

PATENT CLAIMS (1) An engine transport airplane having engines suspended obliquely under the wing so that their steady propulsive force is applied obliquely upwards in a steady horizontal flight so that the airplane flies with the least possible frontal resistance. 2. A motor airliner according to claim 1, characterized in that it has a fuselage shape with high aerodynamic drag resistance and low aerodynamic drag.