RU2584353C1 - Structural elements to increase safety of aircraft with soft wing - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: group of inventions relates to aircrafts heavier than air with a soft wing. First version. Hollow soft wing with an air intake at a tip, the cavity of which is divided into a front and rear segments by a pocket in the form of a webbing, three sides of which are sewn in the middle part of the profile chord to one of the surfaces of the wing and two adjacent ribs in such a way, that with the blown rear segment the free end of the webbing lies down on the wing inner surface with its fourth side forming a return valve. Second version. Hollow soft wing with an air intake at the tip comprising valves in the area of air intakes, the petals of which have four edges, one of which is curved and narrowed at the center, is sewn to the edge of the air intake, and two adjacent to it edges are straight and sewn to the adjacent ribs. Third version. Hollow soft wing with an air intake at the tip, including corrugation system ropes connecting the air intakes and made in the form of loops fixed on the axle-pin of a further when opened section and inserted through eyelets in the rib and on the edge of the previous, when opened, air intake section and fixed by axle-pins attached to the edge of the air intake section. Suspension of a hollow soft wing has loops for attachment of the suspension system at the bottom and free ends with loops for attachment of strings at the top. Ends at the place of the beginning of branching have connections with flexible links secured on the suspension system. Motor suspension of the hollow soft wing is made with the loops for attachment of a suspension system at the bottom and a power plant - at the back, as well as free ends with loops for attachment (hooking) of strings at the top. Hooking loops of the suspension system and the power plant are fixed on a rigid frame of top front, lower front and lower back safety arcs.

EFFECT: group of inventions is aimed at an increase in safety.

6 cl, 10 dwg

Description

FIELD OF THE INVENTION

Transportation; Ballooning, aviation, astronautics; Aircraft are heavier than air.

State of the art

A known type of aircraft with a soft wing, in which the formation of the wing is ensured by the interaction of forces from the incoming flow and from the trimming system. The most effective in this capacity is the soft two-shell wing, consisting of the upper and lower shells connected by ribs with air intakes in the nose. Such a wing acquires a flight configuration due to the action of a complex of multidirectional forces - aerodynamic and internal pressure on the one hand and tension from the trimming system on the other.

When such a wing is opened in flight (the gliding parachute is put into operation), even a small asymmetry of quickly expanding consoles leads to twisting of the dome relative to the suspension, which leads to failure. The most radical solution to this problem would be to force a symmetrical sectional opening of the wing consoles by a corrugation system, however, the systems used with cutters (see, for example, US patents 5893536 A, US 4846423 A and US 5893536 A) or sequential section stripping with additional lines proved to be too complicated operation and expensive. The use of a slider proved to be simpler and more practical. It is grommets mounted on a tape frame with varying degrees of fabric filling, sliding when opening the canopy along slings from the canopy to the harness (see, for example, US Pat. No. 4,678,145 A). The lines of slings are threaded into the eyelets in groups, which leads to the tightening of the segments of the dome with the slider raised. Filling the frame of the slider with fabric increases the pressure on it of the incoming flow and thereby inhibits the sliding of the slider along the lines.

However, the dome compressed by the slider periodically captures the air by randomly opening air intakes, which leads to the partial filling of some of its sections in an erratic combination, and, as a result, throws and moves it along the course, roll and pitch (P.I. Ivanov, A. Yu. Kuyanov, Analysis of the process of filling a planning parachute with a slider // Aerospace Engineering and Technology. - 2012. - No. 6. - P. 33-36). This, as well as possible slopes of the slider when moving along slings, leads to asymmetry in the filling of the dome and the likelihood of it twisting around the suspension. In addition, a large-sized dome equipped with a slider when opening the consoles gives great kinetic energy to the mass of air scattering in its cavity, which, when fixing its shape, leads to a dynamic increase in pressure on the consoles and stretching of the center section, and, as a result, to rupture of the dome fabric. The latter effect forced us to resort to sequentially breaking the dome segments in several stages in the NASA X-38 research program (http://www.parachutehistory.com/images/space/iss/x_38 foildeploy.mpg, http://ntrs.nasa.gov /archive/nasa/casi.ntrs.nasa.gov/20070026249.pdf).

When such a wing reaches negative angles of attack, for example, due to entry into a downward flow, its air intakes lose their ability to maintain excess pressure, the upper leading edge extends, the aerodynamic profile deforms so that its midline in the nose acquires reduced or inverse curvature, and as a result, aerodynamic the force acting on the wing of the wing abruptly changes direction, turning the front segment of the carrier plane. An additional effect during deformation of the profile introduces a backward shift of the center of pressure, which pushes the wing forward and further reduces its angle of attack (to some extent this movement is compensated by an increase in the resistance of the deformed profile).

To counteract this effect, elastic plastic rods are sewn into the wing ribs along the nose contour, reduce the allowance for bloating of the sheath fabric on the forehead of the profile (this also increases the aerodynamic quality, but worsens the resistance of the wing to the yaw moments of the consoles relative to the center section), shift the coordinate of the maximum curvature of the profile as close as possible to toe (also increases Su max, reduces the profile resistance Cx min and increases the allowable trim range, while for pros typical in soft wings s with large relative thickness and fillet radius sock shear flowing characteristics) are stored. In addition, they try to eliminate the rupture of the sheath between the ribs by pressurizing through additional upper air intakes with valves closing these air intakes at large and medium angles of attack (for example, HIT valves (High-Speed Intake Valves) from Arso Aviation, Extended Aeration System (EAS) from U-Turn, air valves at the leading edge of Aeros), or valves separating the wing cavities with the upper and lower air intakes (DE 102006007905 patent). In the latter case, the air entering through the upper air intakes is not vented immediately through the lower air intakes, which have lost their high-pressure head, which makes the positive effect more tangible.

Sometimes they try to maintain boost pressure to the minimum angle of attack through the main air intake, using the fact that when organizing the air intake at any point in the profile so that the inlet to the wing cavity has a non-zero projection on the flow direction at this point, the resulting pressure will be equal to the pressure head ( without taking into account pressure losses due to leaks through the projection of the air intake, parallel to the direction of flow in front of its opening, as well as through pores and cracks in the shell). And at this point on the profile, a region of increased pressure is localized (additional to the region at the point of separation of the flow on the profile), which can fundamentally change the picture of the flow around a hollow profile in comparison with a solid prototype. To date, air intakes have been tested, which are diverted to the profile further from the toe and are either recessed (for example, the Flash wing from UP (1990), patent FR2972422 from Ozone) or slightly protruding from it (for example, the Navigator HS paraglider from ASA-ParAAvis ( 1997), wings Manta, Delta 2 from Ozone, Peak 3 from Niviuk, Pawn from Triple Seven Paragliders, etc.). It should be noted that the option of an air intake with a small projection parallel to the direction of flow in front of its hole causes problems with the filling of the wing in stall and start modes, when the wing experiences a transverse flow.

The above measures push the boundary of the gateway, but only, and when it nevertheless comes, the wing loses air and, until it is refilled, makes unpredictable evolutions, sometimes ending with a sharp change in course, diving the console under the wing with tangling in the slings (“tie”) and autorotation, departure of the wing in front of the pilot with a hit in the dome (the so-called "sweetie") or an unacceptable loss of height until the load-bearing capacity is restored.

Attempts have been made to eliminate the very possibility of a soft-wing nose flap by equipping its air intakes with non-return valves (this solution took root on kite parafoils (for example, in valve parafoils from ParAAvis) as a means of maintaining buoyancy during splashdown), forced boost of the front wing segment (patent RU 2410288 , an experimental wing with an inflatable leading edge of Paradelta (1997)) or placement of rigid spar inserts in the nose of the wing (for example, an experimental paraglider Miser Michael P etrovsky, Hang Gliding Club MAI).

However, these constructive tricks did not solve the problem, but altered it. Namely, albeit with a greater impact, but folding the console for such devices still occurs. In this case, the existing part of the wing does not lose air and does not expand in the flow, reducing resistance, and then does not restore shape gradually, filling up segmentwise from the center section to the tip. With all of its turned-up part, it lies across the stream, and to return it to its original state, counteracting the pressure of air, internal pressure and elastic forces, is not enough. In addition, the turned-up console, falling between the slings of the working part of the wing, is jammed there, and the wing can no longer pull it back. If, however, such a wing enters the region of the downward flow entirely, then it is completely tucked in, laying with its entire plane across the stream. The air pressure throws him far behind the pilot, where it turns around on the stream and abruptly begins to carry, as a result of which, having gained speed on the leveling, it bites the pilot under his feet.

Disclosure of invention

Based on the available experience, the optimal behavior of the soft wing when flying in turbulent air is such that under the influence of a downward flow the carrier plane is not thrown entirely down and back, for which the part of the wing that could provoke such a movement is turned off. The rest of the wing throughout the entire time of unsteady movement remains inflated, regardless of the position of the air intakes, preventing the folding and diving of the consoles. A carrier plane thus deformed continues a straight flight, and as soon as the external action ceases, the wing shape is independently restored, again without violating the straightness of the flight.

Such a deformation of the wing can be ensured by dividing its cavities into the front and rear segments, and the rear segment is equipped with air intakes with non-return valves to ensure boosting and air locking. Structurally, the separation of the cavities is carried out in the form of a pocket made of a cloth sewn in the region of the middle part of the profile chord with its three sides to one of the wing surfaces and two adjacent ribs. The fabric width allowance is selected so that when the rear segment is inflated, the free end of the panel rests on the inner surface of the wing with its fourth side. Such a panel may be, for example, a pocket (item 1) in the slotted wing cavity (patent RU 2389644) shown in FIG. 1 and FIG. 2.

Existing valve designs, described in particular in patents RU 1785184, EP 1295790, DE 3729934, US 3972495, tie the valve panel to the edge of the external air intake, which does not allow the wing to segment by pressure retention and bleed air from the turned part of the console.

Installing the valves on the edges of the external air intakes does not pose a safety problem if the valve flaps do not close completely and gradually release air from the turned up console. If the valves block part of the lumen near the lower or upper edge of the air intake, then it may be useful:

1) to prevent air bleeding through the air intake when the wing toe reaches a small or large angle of attack, at which the flow separation point goes to the edge of the air intake opening;

2) to prevent static or dynamic air bleeding through the air intakes close to the wingtips, due to:

a) changes in local angles of attack due to the influence of an inductive vortex, geometric twist of the wing or local deformation of the profile when controlling the wing;

b) reverse air flow during rapid deformation of the wing due to sharp work by the brakes or air flow from the opposite console when it is folded.

However, the installation of valves in the air intake should not lead to a decrease in its clearance and additional resistance to air absorption during the filling of the wing, otherwise the filling will be slow, which is especially dangerous after tucking and deflating the console. The slower the wing fills in flight, the more unpredictable evolutions it will have time to complete before filling. Therefore, common valve designs in the form of a sleeve or petals adjacent to the grid are unsuitable. Structural elements of the air intake should be short (for quick response) and not block the flow. An attempt to solve this problem was made by the technical solution described in DE 3729934. According to this patent, the valves have vertical wings in the wing of the wing, and the air intake has an unstable section, zero at one of the ribs in which the valve top is fixed from a triangular piece of fabric. The upper and lower edges of the valve blade extending from the top extend into the wing and are sewn to the upper and lower shells of the wing, respectively. The resulting segment of the conical surface can be turned both inside the wing and out. In the first case, the base of the conical surface looks close to the direction along the wing profile, and the air intake is open. In the second case, the base of the cone unfolds across the profile and is adjacent to the nearest rib, blocking the opening of the air intake. The disadvantage of this solution is that the forming edges of the conical surface of the edge are sewn to the curved surfaces of the upper and lower shells, distorting its shape in the open or closed state. In addition, ensuring sufficient clearance is ensured by greatly deepening the base of the tapered surface of the valve into the wing cavity, leading to tissue overruns, increased suction resistance and delayed valve response.

You can use the usual shape of the air intake, do not block the lumen of the air intake and do not reduce its cross section if you use valve petals with four edges, one of which, curved with a narrowing of the petal to the middle, is sewn to the edge of the air intake, and two adjacent to it, straight, are sewn to adjacent ribs. In this case, the valve parts are obtained in a minimum size and provide high performance. Thanks to the curved leading edge, the valve petal has two stable positions. In the open state, the valve has an inlet rectangular section at the edge of the (rectangular) air intake and an outlet in the wing cavity in the form of interlocking circular arcs, while the areas of the inlet and outlet sections of the air intake can be equal to what we need. When the petals are closed, their trailing edge extends forward and is held transverse to the flow due to the tension from the side edges held by the ribs. In this case, the trailing edges of the valve either close together (which is permissible on the center section), or remain at a certain distance from each other, forming a gap for emergency air bleeding (which is desirable on the consoles).

In addition to the wing, safety is affected by the trimming system, since it cannot absorb a compressive load, and at the same time has a relatively high tensile stiffness to avoid noticeable deformations of the wing profile in the flight position. As a result of this, the wing console that has fallen into the downward flow loses its support and goes down, and after restoring its shape and beginning to move upward, it stops abruptly with slings, which causes overloads in their attachment points. The use of elastic links in the free ends or directly below them can reduce overloads during opening. It is also able to increase flight comfort, because it smooths out the blows transmitted from the wing to the suspension in turbulent air, similar to how a car’s suspension behaves on a bumpy road. This installation location of the elastic links allows you to tighten and lower the wing console without breaking its shape. Using these same structural elements, you can increase the wing resistance to folding. This effect occurs insofar as the cantilever falling into the downward flow loses its lifting force, and the energy accumulated in the elastic link supporting the cantilever draws the weakened cantilever to the suspension, thereby translating it to a larger angle of attack relative to air. Conversely, when entering the upward flow, the lifting force of the cantilever increases sharply and the elastic link stretches. The wing rises, reducing the angle of attack relative to air, which prevents the flow from stalling.

When the parachute-wing is opened in the air, sequential segmented opening of the consoles from the center section to the wing ends can be achieved without the use of knives and additional slings by sequentially striking sections of the air intakes pressed into each other by means of notching loops (pos. 7 of Fig. 9-10. ), threaded through the eyelets in the ribs and the lower edge of the air intake (pos. 6 and 5, respectively, Fig. 9-10) and fixed with checks (pos. 4 of Fig. 9-10), sewn to the lower edge of the air intake so that vobozhdenie loop for locking occurs only after filling previous section of the wing and the lower edge tensioning inflated air intake section. To eliminate the possibility of spontaneous descent of checks at the section closest to the center section, the position of the check is not fixed by the notch loop, but by a tape or cord fixed on a rib in a breaking lock, for example, such as a Velcro. The clipped section closest to the wing end has no checks and eyelets on the lower edge of the air intake as unnecessary.

In addition to the above elements, the suspension itself affects safety. The motor suspensions currently in use (see, for example, WO 2009/151351) have minimal passive safety features, including a screw guard and (sometimes) a shock-absorbing cushion under the pilot's seat. Meanwhile, most of the flight is maneuvering at low altitudes. This is especially true for sports flights. When the cantilever is tilted at low altitude due to falling into the surface airborne inhomogeneity, loss of height leads, as a rule, to a collision with the ground. In such a situation, both time and altitude are not enough to launch a parachute. A typical direction of impact is to the front side. The second danger of flying at low altitude is the risk of getting into the power line, which against the background of the earth has low visibility, especially in conditions of limited visibility. Suspensions currently in use do not protect against this danger either. Meanwhile, typical flight speeds (about 100 km / h for suspension on a bend), coupled with the accumulated experience of using passive protection for the crew of a car and a motorcycle, make it possible to use a safety cage to increase the safety of the pilot. The proposed roll cage consists of rigidly connected upper, lower front and lower rear safety arches. Between the upper and lower front arches are stretched cables to protect against getting into the power line, as well as to give additional structural strength. The propeller frame is rigidly attached to the rear safety arches to prevent the movement of massive elements forward upon impact. The free ends are attached to the upper safety bar. The latter also increases safety, since a wide suspension makes it easier to take the wing into flight position, and with sharp wing evolutions or under the influence of the Coriolis moment from the propeller when taking off at full throttle, it reduces the risk of a twist (twisting of the suspension relative to the slings). The system can be supplemented by means of automatic grouping of limbs by pulling the pilot’s arms and legs to the hull when struck by a device, for example, similar to the operating principle of the PPK-U device, only with an overload trip. In the latter case, the safety ropes in the flight position are in the grooves of the overalls, just as the ends of the rescue parachute are laid in the suspension.

Brief Description of the Drawings

In FIG. 1 and FIG. 2 shows a wing section divided into front and rear segments by a pocket-valve 1 in open and closed states, respectively.

In FIG. 3 and FIG. 4 shows the valve on the air intake in the nose of the wing in open and closed states, respectively. In FIG. 5 shows sweeps of valve petals. These figures indicate: 1 - the upper valve flap, 2 - the lower valve flap, 3 - the edge of the valve flap sewn to the edge of the air intake, 4 - the free edge of the valve flap, 5 - the edge of the valve flange sewn to the rib.

In FIG. 6 shows a cross section of a suspension with elastic links, where 1 is a rigid seat insert, 2 is a shock-absorbing seat gasket, 3 is a side suspension strap, 4 is a carabiner of connection with free ends, 5 is an elastic cord in a braid, 6 is the position of the upper elastic node cord in unstretched condition.

In FIG. 7 and FIG. 8 depicts a motor suspension with safety arcs, where: 1 - propeller-mount frame with rigid fastening to the upper arc 2 and lower rear arch 3 of the suspension frame, 4 - lower front suspension arc, 5 - protective cable, 6 - transparent visor, stretched over cables 5 (option).

In FIG. 9 and FIG. 10 depicts sections of the air intakes of the wing in the chocked and chipped states, respectively, where are indicated:

1 - the lower edge of the air intake, 2 - the upper edge of the air intake,

3 - rib, 4 - check, 5 and 6 - eyelets at the leading edges of the lower edge of the air intake and ribs, respectively, 7 - notch loop, 8 - lower wing surface.

Claims (6)

1. A hollow soft wing with an air intake in the toe, including the lower surface, upper surface and ribs, characterized in that its cavity is divided into front and rear segments by a pocket in the form of a cloth sewn in the middle part of the chord of the profile with three sides to one of the surfaces the wing and two adjacent ribs in such a way that when the rear segment is inflated, the free end of the panel lies on the inner surface of the wing with its fourth side, forming a check valve. 2. A hollow soft wing with an air intake in the toe, including the lower surface, upper surface, ribs, as well as valves in the area of air intakes, characterized in that the valve petals have four edges, one of which, curved with a narrowing of the petal to the middle, is sewn to the edge air intake, and two adjacent to it, rectilinear, sewn to adjacent ribs. 3. A hollow soft wing with an air inlet in the toe, including the lower surface, upper surface, ribs and air-tightening cords of the corrugation system, characterized in that the cords are made in the form of loops fixed to the check later when opening the section, threaded through the eyelets in the rib and on the edge of the air intake of the previous section when opened and fixed by checks fixed to the edge of the air intake of this section at such a distance from the eyelet that the check is similar when the edge of the air intake is pulled . 4. Suspension of a hollow soft wing with hinge hooks of the suspension system at the bottom, as well as free ends with sling attachment loops at the top, characterized in that the ends under the branching start point are connected to elastic links fixed to the suspension system. 5. The motor suspension of the hollow soft wing with the hinges of the suspension system hitch at the bottom and the propeller installation at the rear, as well as the free ends with the hinges of the slings at the top, characterized in that the hinges of the suspension of the suspension system and the screw installation are mounted on a rigid frame from the upper front, lower front and lower back safety arch. 6. The motor suspension according to claim 5, characterized in that protective cables are stretched between the upper front and lower front safety arches on the sides of the pilot's legs.

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