Method of aerodynamically stabilizing an airship in an air flow

Abstract

The invention relates to the field of aviation, and more particularly to a method of controlling an airship. A method of stabilizing an airship without a tail assembly in an air flow includes: determining an air flow-induced force effect and the dynamics of said effect on the hull of the airship using pressure sensors arranged along four meridian lines at 90 degrees to the axis of the airship, with five sensors on each line; transmitting data about the distribution of pressure on the envelope of the airship to a computer; and generating, with the aid of software, the necessary algorithms for control pulses which are brought about with the aid of at least four thrust vector generating units. The result is that of stabilizing an airship without a tail assembly in an air flow to increase flight safety and reduce energy expenditure during movement in a given direction.

Description

[0001] Method of aerodynamic stabilization of an airship in an air flow

[0002] The invention relates to the field of aviation, in particular to a method for controlling an airship.

[0003] Current state of the art.

[0004] There are airships of the classic cigar shape with a cross-section in the form of a circle or oval. Airships have different designs, such as: a non-rigid airship consisting of a shell, the shape of which is maintained by the lifting gas contained in it; a semi-rigid airship consisting of a power keel beam and a shell attached to it, the shape of which is maintained by the lifting gas contained in it; a rigid airship consisting of a frame covered with a shell, supporting the external shape and carrying all the heavy elements and the payload, such as a gondola and a propeller-motor unit, the lifting gas is contained in one or more gas bags.

[0005] Modern flying airships built before 2013 have a classic shape, small volume (up to 10 thousand m3) and are capable of carrying a small payload (up to 2 tons). They are mainly intended for inspection, tourism, advertising. Any serious transport tasks are beyond their capabilities.

[0006] Classic airships are moored to a mooring mast, have a tail unit as an integral control element, which serves to control the position of the airship in the flow during its movement or to orient itself along the flow when the airship is at the mooring mast. When there is a side gust of wind, the air flow acts on the tail unit. It experiences a lifting force directed perpendicular to the flow, and a resistance force, which additionally loads the mast.

[0007] The result of such wind action is the rotation of the airship and the displacement of its cabin from its original position. If loading was in progress, the loaders must move to another location. For this reason, the mooring area must be at least twice as large as the airship itself.

[0008] The problem of airship maneuverability is aggravated by the growth of the carrying capacity, and therefore the size of the airship. The moment of inertia relative to the center of gravity of the airship grows in cubic dependence on its linear dimensions, and if for linear movement, along its main axis, the airship requires a propeller-motor installation with a thrust 4-5 times less than for an aircraft of the same carrying capacity, then for active maneuvers to turn the airship along the course and pitch of the thrust of these installations 1

[0009] SUBSTITUTE SHEET (RULE 26) is not enough. This problem is aggravated by the classical installation near the longitudinal axis of the airship. And this has been the cause of airship accidents more than once. Therefore, a classical airship cannot quickly maneuver to avoid a collision with an obstacle, and, on the other hand, it cannot quickly turn its nose to a side gust of wind, which can also lead to a strong drift and an accident.

[0010] Much more complex and significant is the force impact of the air flow, created as a result of the airship flight in adverse weather conditions and high atmospheric turbulence. In addition to horizontal wind shears, there are also ascending and descending flows, which can affect the bow and stern of the airship in different ways. Therefore, to develop control actions, it is necessary to know not only the general wind direction, but also the direct force impact of the air flow on the envelope, which is implemented by this invention.

[0011] Invention US7264202 is known, which proposes to equip an airship with cyclic thrusters located along the three main axes of the airship. Cyclic thrusters produce high static thrust on one side, and on the other side the thrust vector can be quickly directed in any direction.

[0012] However, the invention does not specify the criteria by which the orientation of the airship should be carried out when parked or in flight. In addition, it has three cyclic thrusters located perpendicular to the main axis of the airship, and one on the bow and stern with an axis parallel to the axis of the airship, such an arrangement is quite effective for movement at speeds of up to 10 m / s and at low maneuvering speeds. But with an increase in the speed of movement, the energy efficiency of cyclic thrusters located across the flow is greatly reduced, compared to propellers, which worsens the economic indicators of the airship. The bow and stern cyclic thrusters located far from the center of gravity also worsen their efficiency due to the high translational speed when turning the airship around the vertical axis.

[0013] There is a patent FR3036475, which solved the problem of developing criteria for controlling an airship by placing a sensor on it that determines the wind direction, connecting it to a system that generates control actions on the stabilizer rudders and propeller-motor units. However, the invention does not take into account that due to the large size of the airship, it may end up in flow conditions, where at different altitudes the wind has different strength and even different directions, so developing an adequate control action with such a diagnostic system is difficult.

[0014] In addition, in conditions of large-scale ground turbulence, the very presence of a tail unit can cause additional problems. Tail 2

[0015] SUBSTITUTE SHEET (RULE 26) the tail is essentially a wing, has a narrow range of attack, and works effectively as a stabilizer at a deviation of 20 degrees in any direction.

[0016] In a situation where a sudden side gust of wind occurs, the tail will be at a large angle of attack, and the flow will stall, which will greatly increase the overall resistance of the airship and reduce the efficiency of the tail as a control element. In a situation where the tail operates within its pre-stall angles of attack, under control action it can create a drag force comparable to the resistance of the main body of the airship during its longitudinal flow. This also reduces the energy efficiency of the airship as a transport system.

[0017] The technical result, which the invention is aimed at achieving, consists in ensuring the stabilization of an airship without a tail assembly in order to increase flight safety and reduce energy costs when moving in a given direction, in which the airship is positioned with its longitudinal axis strictly against the average flow speed.

[0018] The stated technical problem is solved in that in the method of stabilizing an airship without a tail assembly in an air flow, consisting in determining the force action and the dynamics of change of this action on the airship shell from the air flow using at least 22 pressure sensors, located at least 5 pieces along at least four meridional lines at 90 degrees relative to the airship axis, a computer that receives data on the pressure distribution on the airship skin, software that generates the necessary algorithms of control pulses, which are implemented using at least four thrust vector creation posts consisting of cyclopropeller movers with an axis of rotation parallel to the airship axis, located parallel and symmetrically to its vertical plane outside the skin, in the range from 30 to 70% along the airship chord.

[0019] The stated task is also achieved by the fact that, in order to increase the efficiency of the proposed method, the variable-pitch propeller and the cyclic thruster of the thrust generation post can rotate both together and separately, and the variable-pitch propellers for generating thrust in the horizontal plane can be located only on the two rear or on the two front posts.

[0020] An example of a specific implementation of thrust generation posts and a method for stabilizing an airship in an air flow is presented in the drawings, which show in Fig. 1 a general view of an airship with a cigar-shaped shell, with 3

[0021] SUBSTITUTE SHEET (RULE 26) sensors and thrust generation posts. Fig. 2 - the composition of the thrust generation post of the airship, Fig. 3 - the airship (side view) in balanced horizontal flight, Fig. 4 - the airship (side view) with deviation from horizontal flight in pitch, Fig. 5 - the airship (top view) in balanced horizontal flight, Fig. 6 - the airship (top view) with deviation from horizontal flight in course.

[0022] Implementation of the method

[0023] The implementation of the control method is as follows. The lighter-than-air aeronautical apparatus consists of a cigar-shaped rigid or semi-rigid shell (1), of circular or oval cross-section, like a classic airship, with a payload compartment (2), a control computer (3) inside the airship shell (1), meridional lines (4) located along the airship axis (5), pressure sensors (6) showing the magnitude of static pressure on the skin, located on the nose, tail and evenly distributed over the airship skin at 90 degrees, thrust generation posts (7).Thrust generation post Fig. 2 is the mounting post for the thrust generation post to the airship (8), a cyclic mover (9) used to generate thrust in the transverse direction by 360°, a variable-pitch screw propeller (10) generating thrust in the longitudinal direction, maintaining high efficiency at cruising airship flight speeds from 30 to 40 m / s, front fairing (I), rear fairing (12).The axis of rotation of the thrust generating post movers (7) is parallel to the airship axis (5) and is located parallel to its horizontal plane. The thrust generating posts are attached either directly to the airship skin, if it is rigid, or by means of beams or trusses connected to the payload compartment (2) of the airship, at a distance of 30-70% along the airship chord.

[0024] The invention is illustrated by figures 1-6, which indicate the following positions:

[0025] 1 - Airship shell;

[0026] 2 - Payload compartment;

[0027] 3 - Control computer;

[0028] 4 - Meridional lines

[0029] 5 - Axis of the airship;

[0030] 6 - Pressure sensor;

[0031] 7 - Thrust generating posts;

[0032] 8 - Mounting stand for the thrust generation post to the airship;

[0033] 9 - Cyclic mover;

[0034] 4

[0035] SUBSTITUTE SHEET (RULE 26) 10 - Variable pitch propeller;

[0036] 11 - Front fairing;

[0037] 12 - Rear fairing;

[0038] 13 - Diagram of pressure force distribution;

[0039] 14 - Generalized aerodynamic force F a ;

[0040] 15 - Center of gravity of the airship;

[0041] 16 - Horizontal traction T х ;

[0042] 17 - Vector of the velocity of the oncoming flow;

[0043] 18 - Transverse vertical thrust T у ;

[0044] 19 - Transverse horizontal traction T z .

[0045] Maneuverability, mastless takeoff and landing, and compensation for crosswind gusts remain the most important goals, so the task of the invention is to solve these problems.

[0046] A method is proposed for stabilizing an airship in an air flow of a rigid or semi-rigid structure, without a tail unit, in which the position of the airship in the flow is monitored using objective criteria, measuring the force impact on the airship from the air flow, with the aim of achieving maximum energy efficiency and safety.

[0047] In this example, the lighter-than-air aircraft used is an airship that is 72 m long and has a helium volume of 8100 m3. 3 , with a rigid shell (1) of a cigar-shaped circular cross-section, without a tail unit. In other embodiments, the shells can be soft and semi-rigid. But then the thrust generation posts are connected to the payload compartment using additional power trusses.

[0048] In this example, the payload compartment (2) is located inside the airship. On the shell (1) there are 22 pressure sensors (6), showing the value of static pressure on the skin. Studies of the pressure distribution on the airship surface show that it depends little on the position and operation of the propellers, however, to adequately construct the pressure distribution curve along the meridional line, it is necessary to know the static pressure value at least at 5 points along the meridional line. And also at the nose and tail of the airship, and to determine the force effect on the shell at angles of attack, it is necessary to take measurements at least along 4 meridional lines located at an angle of 90 degrees relative to the axis of the airship, thus, the number of pressure sensors cannot be less than 22. One sensor is located in the nose of the airship, the second in the tail. The remaining sensors

[0049] 5

[0050] SUBSTITUTE SHEET (RULE 26) are distributed evenly over the entire skin of the airship, 5 pieces in 4 meridional lines (4), along the axis of the airship, lying on the skin at 90 degrees.

[0051] We will consider the control of the airship by the pitch angle using the following examples in Fig. 3 and Fig. 4. The data from the pressure sensors (6) in Fig. 3 are sent to the on-board computer (3), which, using this data, reconstructs the pressure force distribution diagram (13) over the airship shell and determines the general external effect of the flow on the airship, expressed by the generalized aerodynamic force F a (14), determining its point of application, direction and modulus relative to the center of gravity (15). In the case of steady horizontal flight, the pressure distribution diagram (13) has a symmetrical form (Fig. 3) and this case corresponds to the minimum resistance of the airship in the flow, the generalized aerodynamic force F a(14) is minimal and is located along the axis of the airship. The control computer issues commands to create horizontal thrust T х (16), which is created by a variable pitch propeller (10). If the wind effect on the airship changes and an angle of attack a occurs between the velocity vector of the incoming flow (17) and the axis of the airship (5) (Fig. 4), the pressure distribution diagram (13) changes, which leads to a change in the direction and vector of the generalized aerodynamic force F a . It increases and begins to create a destabilizing moment Ma, Ma = F a *h a . In this case, the computer issues a control action to the thrust generation posts (7) and turns on the cyclic thrusters (9), which create transverse vertical thrust T у (18), thereby creating a compensating moment M с . M с = T y *h t. This moment rotates the airship around the transverse horizontal axis until the pressure distribution diagram again becomes symmetrical and the generalized aerodynamic force F a will become minimal.

[0052] We will consider the control of the airship by the yaw angle using the following examples. Fig. 5 - the airship (top view) in balanced horizontal flight. Fig. 6 - the airship (top view) with a deviation from horizontal flight along the course. Data from the pressure sensors (6) Fig. 5 are fed to the on-board computer (3), which, based on this data, reconstructs the pressure force distribution diagram (13) along the airship shell and determines the general external effect of the flow on the airship, expressed by the generalized aerodynamic force F a(14), determining its point of application, direction and modulus relative to the center of gravity (15). In the case of steady horizontal flight, the pressure distribution diagram (13) has a symmetrical form (Fig. 5) and this case corresponds to the minimum resistance of the airship in the flow, the generalized aerodynamic force F a (14) is minimal and is located along the axis of the airship. The control computer issues commands to create horizontal thrust T х (16), 6

[0053] SUBSTITUTE SHEET (RULE 26) which is created by the screw propeller (10). If the wind effect on the airship changes and a slip angle P occurs between the velocity vector of the incoming flow (17) and the axis of the airship (5) (Fig. 6), the pressure distribution diagram (13) changes, which leads to a change in the direction and vector of the generalized aerodynamic force F a . It increases and begins to create a destabilizing moment Ma, Mc = F a *h a. In this case, the computer issues a control action to the thrust generation posts (7) and turns on the cyclic thrusters (9), which create transverse horizontal thrust T z (19) A compensating moment M is created. с . M с = T z *h t . This moment rotates the airship around the transverse vertical axis until the pressure distribution diagram again becomes symmetrical and the generalized aerodynamic force F a will become minimal.

[0054] The minimum number of control posts is four. This is necessary for safety, in case of failure of one installation, since the minimum number of posts required for this method of control is three. Based on the general laws of mechanics, it is known that in order to stabilize any body or move it in any direction, 3 thrust generation points located in one plane are necessary and sufficient. Therefore, to control and stabilize an airship without a tail, 3 thrust generation posts are necessary and sufficient, where the vector and magnitude of thrust can change in an arbitrary direction. However, if one post fails, the airship partially loses control. If 4 posts are installed in one plane, then the failure of any of the 4 posts does not lead to loss of control. The number of control posts may be greater than 4, but this entails additional weight and energy costs, and the reliability of the system is already excessive.

[0055] 7

[0056] SUBSTITUTE SHEET (RULE 26)

Claims

Formula 1. A method for stabilizing an airship without a tail assembly to increase flight safety and reduce energy costs when moving in a given direction, in which the airship is positioned with its longitudinal axis strictly against the average flow velocity, consists in determining the force action and the dynamics of change in this action on the airship shell from the air flow using at least 22 pressure sensors located in at least five pieces along at least four meridional lines at 90 degrees relative to the airship axis, a computer that receives data on the pressure distribution on the airship skin, software that generates the necessary algorithms for control pulses, and correction of the longitudinal axis of the airship in the flow using the generated pulses through four thrust generation posts consisting of cyclopropeller movers with an axis of rotation parallel to the airship axis,located parallel and symmetrically to its vertical plane outside the skin, in the range from 30 to 70% along the chord of the airship.

2. An airship according to paragraph 1, characterized in that there may be more than 22 pressure sensors.

3. An airship according to paragraph 1, characterized in that there may be more than 4 meridional lines along which the sensors are located.

4. An airship according to paragraph 1, characterized in that the variable-pitch propeller and the cyclic thruster of the thrust generation post can rotate both together and separately from each other.

5. An airship according to paragraph 1, characterized in that the tail assembly may be present.

6. An airship according to paragraph 1, characterized in that there may be more than 4 thrust generation posts.

7. An airship according to paragraph 1, distinguished by the fact that only cyclic or only propeller propulsion units may be installed at the thrust generation posts. 8 SUBSTITUTE SHEET (RULE 26)

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