RU2544279C2 - Integrated wing tank of aircraft - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aviation, to wing tanks of aircraft. Wing tank(s) is (are) of the form of leakproof cylinders or cones located in wing intracavity and serves(serve) as longitudinal load bearing element of wing structure. Inside the tank, vertical permeable baffle plate of flat, T-shaped cross-section or in the form of girder, channel bar or I-girder is located. The tank can also be made from one outer wing end to the second outer wing end.

EFFECT: improved safety of wing structure.

10 cl, 4 dwg

Description

The invention relates to wing fuel tanks of aircraft.

Known fuel tanks of aircraft located in the wings, see.with. USSR No. 146651. Their disadvantage is that they have significant weight. Caisson tanks are also known, but they also have their drawback - their tightness is often violated due to wing deformations during flight loads. And their repair is very difficult. Profiles of circular cross section (pipe) used as power elements are also known, see Russian Patent No. 2033940.

Currently, environmental and economic considerations make it advisable to use gaseous fuels - liquefied propane or compressed methane. In technology, containers for them are called cylinders, but in the future we will call them the aviation term "tanks". A feature of such tanks is also that they cannot have an arbitrary shape. Due to a sufficiently large internal pressure, they must have a round shape in the cross section - a sphere, cylinder, rotation ellipsoid.

The use of such tanks is very problematic - due to a sufficiently large internal pressure, their walls must be thick enough and, therefore, their mass will be unacceptable for an aircraft.

The objective of the invention is to make economically and technically feasible the construction and operation of gas-fired aircraft.

The technical result of the invention lies in the use of a robust construction of the tank (tanks) as a longitudinal bearing element of the wing structure - as a spar (spars). And also if there are several tanks, a second technical result is possible - the use of a bunch of tanks connected to each other and with the skin as an element of the transverse strength of the wing - as a substitute for ribs.

To do this, this tank / tanks are in the form of sealed cylinders located in the inner cavity of the wing (in the wing of the constant chord), or in straight or animated cones (in the trapezoid and elliptical wings), see Fig. 1. Tanks can be made of light alloys or of composite material.

Such a tank, which is, for example, a conical pipe (i.e. a truncated round cone), can withstand a bending load. Several such tanks of different sizes can be located in the wing profile, which will further increase the bearing capacity of such a structure.

The bending strength of a straight or conical pipe increases the presence of internal pressure in it (increasing the strength stability).

To increase the longitudinal bending strength of the tank inside the tank, a vertical transverse non-tight partition of a flat, T-shaped cross-section, or in the form of a truss, channel, I-beam (in all cases of combining this alternative feature with any of the main features, the same technical result can be achieved) ), (all directions hereinafter are given relative to the direct horizontal position of the aircraft). If there are several tanks, then all tanks can have a partition, but the partition in the largest tank located along the thickness of the chord will work most rationally (this option is shown in Fig. 1). And also - to reduce the likelihood of flutter - in the front tank.

To increase the strength stability, a flat partition may have vertical corrugation in the middle part.

If the partition has a T-shaped appearance, or the appearance of a channel or an I-beam, then its horizontal shelves should have a rounding in radius corresponding to the radius of this tank in this section.

It should be borne in mind that the rigidity of the partition is greater than the pipe (cylindrical or conical), and the destruction will begin with it. Therefore, the materials used for the partition must have a lower modulus of elasticity or a much greater tensile strength in compression and tension. The evaluation criterion is failure at the same strain.

An increase in pipe bending strength can also be achieved with ring-shaped internal reinforcements located at a certain pitch. And also in the most loaded places, for example, in the place of attachment of struts.

And for better aggregate strength work of the tubular tank, vertical baffle and wing sheathing, the tank can be connected to the sheathing through lodges of the corresponding profile (position 4 in figure 2). Lodges can be made of composite or foamed material.

In the same way, to increase the overall strength and rigidity, the side walls of several tanks can also be connected to each other (lodgements 5 in FIG. 3).

The partition to the tank, the tank to the lodgements, the tanks between themselves and the lodgements to the wing sheathing can be fixed, for example, with glue, soldering or in another way, depending on the materials used.

The ends of the tanks should have conical, semicircular or semi-elliptical tips. Moreover, in order to avoid weighting and weakening of the structure in the places where the tanks are attached to the center section, it makes sense to make the tank continuous from the end of one console to the other. In this case, the tank will take the form of a combination of two truncated cones or a combination of two truncated cones and a cylinder between them (hereinafter referred to as the “all-wing” tank).

The tank of the wing of a constant chord in this case will have the form of a cylindrical pipe of constant diameter. But such a pipe will experience uneven loads - the closer to the center section, the more. Therefore, such a tank should have an unequal wall thickness - in the area of the center section, the wall thickness should gradually increase. An increased wall thickness should have a pipe (and not just a cylindrical one) in the area of the strut mount.

In order to avoid uncontrolled flow of liquefied gas during the evolution of the aircraft, the whole-wing tank must have one or more transverse membranes inside with check valves directed to the center section (preferably in the lower part of the membrane), where the fuel will be taken.

Refueling nozzles, given the V-shaped wing of the aircraft, it is advisable to make near the ends of the wing consoles. Moreover, in order to ensure complete filling and so as not to tear the membranes with a pressure drop, the membranes must have bypass valves that open at a given pressure drop (preferably in the upper part of the membrane).

Figure 1 shows in cross section a wing 1 with integrated tubular tanks 2, which are spars, and in the largest tank there is a vertical I-beam 3.

In Fig.2, the joint of the partition 3, the tank 2, the lodgment 4 and the skin of the wing 1 is enlarged. All connections are glued or soldered.

Figure 3 shows an enlarged joint of the side surfaces of two tanks 2, which are glued or welded together and with lodgements 5.

Figure 4 shows the dotted arrangement of the tanks 2 in the wing 1 of the trapezoidal profile, where 6 is the fuselage.

The tank (s) operates as follows: through the filling nozzles, the tank is charged with liquefied or compressed gas. Moreover, for a single-wing tank, simultaneous filling from both ends of the wing consoles is desirable (so as not to overload the bypass valves). At the first refueling, it is advisable to put the plane in a small roll position and fill the tank from the lower console, bleeding air from the upper console.

The selection of fuel for engines should be carried out from the bottom of the tank, that is, in the center section.

Claims (10)

1. An integrated wing fuel tank of an aircraft, comprising a gas tank (s), characterized in that the tank (s) are in the form of sealed cylinders or cones located in the inner cavity of the wing and fulfill the function of a longitudinal bearing member of the wing structure. 2. Tank according to claim 1, characterized in that several such tanks of different sizes are located in the wing profile. 3. The tank according to claim 1, characterized in that inside the tank there is a transverse untight partition of a flat, T-shaped cross-section, or in the form of a truss, channel, I-beam. 4. The tank according to claim 1, characterized in that the vertical partition may have a vertical corrugation in the middle part. 5. The tank according to claim 1, characterized in that if the partition has a T-shape, or the appearance of a channel or an I-beam, then its horizontal shelves are rounded in radius corresponding to the radius of the tank in this section. 6. The tank according to claim 1, characterized in that it has ring-shaped internal reinforcements located with a certain step and in the most loaded places. 7. Tank according to claim 1, characterized in that the tank / tanks are connected to the casing and to each other through lodges of the corresponding profile, fastened by soldering or gluing. 8. The tank according to claim 1, characterized in that the tank is located from the end of one console to the end of the other. 9. The tank according to claim 1, characterized in that it has an unequal wall thickness - in the area of the center section, the wall thickness gradually increases. 10. The tank according to claim 1, characterized in that it has inside one or more transverse membranes with check valves directed to the center section, and with bypass valves.

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