A control method for reducing the disturbance torque of large flow trajectory control jet

Abstract

The present invention relates to a control method for weakening the interference torque of a large-flow orbit control jet. By arranging a protrusion at a suitable position on the windward surface of a tail skirt of an aircraft model, the local high pressure induced by the protrusion on the tail skirt provides a pitch torque, which can reduce the influence of orbit control interference and improve the stability of interception missiles. Further, the present invention determines the arrangement position of the protrusion at the surface flow reattachment line position on the windward surface of the tail skirt of the aircraft model through optimization design, and determines the angle of the protrusion around the tail skirt part of the aircraft model in the circumferential direction and the height and width of the protrusion through optimization design, so that the control method of the interference torque is optimized. Compared with the attitude control engine control method, the present invention does not require additional energy input, has a simple structure, is easier to implement, and can also be used as a supplement to the attitude control engine control method.

Description

Technical Field

[0001] The invention discloses a control method for weakening the interference torque of a large flow rate track control jet, belonging to the technical field of flow control. Background Art

[0002] Jet control technology is an active flow control technology that directly changes the flight trajectory or attitude of an aircraft through the reaction force of the jet. It has the advantages of fast response speed, no restrictions on airspace and speed domain, and high control accuracy. The flight range of future hypersonic aircraft will range from low altitude to high altitude, covering dense atmosphere to thin atmosphere. The aerodynamic force varies greatly under different environments, and it is necessary to use the direct force provided by the large flow trajectory control engine to maneuver and change the trajectory to achieve high precision and fast response capabilities.

[0003] Large flow rate orbit control jet interference will produce a large interference torque, and attitude control engines are often used for control at home and abroad. However, under certain conditions (such as low altitude and high Mach number flight conditions), orbit control jet interference will produce a large interference torque, and the attitude control engine control capability is difficult to perform stable control of the aircraft, so additional control methods are needed to further control the interference torque. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a control method for reducing the interference torque of large-flow orbit control jets. By arranging protrusions at appropriate positions on the windward surface of the tail skirt of an aircraft model, the local high pressure induced by the protrusions on the tail skirt provides a pitch torque, which can reduce the impact of orbit control interference and improve the stability of intercepting missiles.

[0005] The above-mentioned purpose of the present invention is mainly achieved through the following technical solutions:

[0006] A control method for reducing the disturbance torque of a large flow trajectory control jet, comprising:

[0007] Build an aircraft model.

[0008] Arrange a protrusion on the windward side of the tail skirt of the aircraft model, or,

[0009] Firstly, the attitude control engine is used to control the attitude control jet interference, and then protrusions are arranged on the windward surface of the tail skirt of the aircraft model.

[0010] In the above-mentioned control method for reducing the interference torque of a large-flow orbit control jet, the protrusion is arranged at the surface flow reattachment line position of the windward surface of the tail skirt of the aircraft model.

[0011] In the above control method for reducing the interference torque of a large flow rate track control jet, the determination of the arrangement position of the protrusion includes:

[0012] The spatial velocity of the jet interference flow field of the aircraft model is obtained by a numerical simulation method, the streamlines of the jet interference flow field are obtained according to the spatial velocity, and the limiting streamlines of the aircraft model surface are extracted from the streamlines;

[0013] The surface flow reattachment line position of the windward surface of the tail skirt of the aircraft model is obtained by using the limiting streamline of the aircraft model surface, that is, the arrangement position of the protrusion.

[0014] In the above control method for reducing the large flow rate orbit control jet interference torque, the spatial velocity of the jet interference flow field of the aircraft model is obtained by a numerical simulation method, including:

[0015] The aircraft model is a cone-cylinder skirt trajectory control jet model, and the spatial velocity of the jet interference flow field of the aircraft model is obtained by solving the three-dimensional compressible Navier-Stokes equations.

[0016] In the above control method for reducing the large flow rate orbit control jet interference torque, the method for obtaining the spatial velocity of the jet interference flow field of the aircraft model by solving the three-dimensional compressible Navier-Stokes equations includes:

[0017] (1) The three-dimensional compressible Navier-Stokes equations are:

[0018]

[0019] in, is a conserved variable, are the inviscid flux vectors in the three directions of the coordinate system x, y, and z, respectively, are the viscous flux vectors in the three directions of x, y, and z in the coordinate system respectively; t is time, x is the flow direction of the coordinate system, y is the normal direction of the coordinate system, and z is the circumferential direction of the coordinate system;

[0020] The coordinate system is defined as follows: a three-dimensional Cartesian rectangular coordinate system is used, with the x-axis along the model flow direction, the y-axis along the normal direction, the z-axis along the circumferential direction, and the coordinate origin O selected as the midpoint of the leading edge of the aircraft model;

[0021] (2) Solve the three-dimensional compressible Navier-Stokes equations to obtain the conserved variables The spatial velocities u, v, and w of the jet interference flow field are obtained; u is the stream velocity, v is the normal velocity, and w is the circumferential velocity.

[0022] In the above-mentioned control method for reducing the interference torque of a large-flow orbit control jet, the protrusion circumferentially surrounds a partial area on the surface of the tail skirt of the aircraft model, and the arc center angle of the surrounding area is 30° to 60°.

[0023] In the above control method for reducing the interference torque of a large flow rate track control jet, the height h of the protrusion satisfies:

[0024] h / D=0.01~0.1,

[0025] Where: D represents the tail skirt diameter of the aircraft model.

[0026] In the above control method for reducing the interference torque of a large flow rate track control jet, the width w of the protrusion satisfies:

[0027] w / D=0.01~0.1,

[0028] Where: D represents the tail skirt diameter of the aircraft model.

[0029] In the above control method for reducing the interference torque of a large flow rate orbit control jet, when the control torque generated by the protrusion is greater than or equal to the interference torque of the orbit control engine, the protrusion is arranged on the windward surface of the tail skirt of the aircraft model to control the interference torque;

[0030] When the control torque generated by the protrusion is smaller than the interference torque of the orbit control engine, the attitude control engine is first used to perform attitude control jet interference control, and then the protrusion is arranged on the windward surface of the tail skirt of the aircraft model.

[0031] In the above control method for reducing the large flow rate track control jet interference torque, the pitch moment control efficiency η that characterizes the protrusion control effect is expressed as follows:

[0032]

[0033] Where: ΔMz 凸起物 represents the pitch disturbance moment caused by the orbital control jet of the bump model, ΔMz represents the pitch disturbance moment caused by the orbital control jet of the no-bump model,

[0034] η = 0 means that the protrusion has no control effect;

[0035] η>0 means that the protrusion produces adverse control;

[0036] -1<η<0 means that the protrusion produces favorable control, and the smaller η is, the higher the control efficiency produced by the protrusion is;

[0037] η=-1 means that the pitch disturbance torque generated by the protrusion completely offsets the adverse effect of the jet interference flow field.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The present invention provides a control method for reducing the interference torque of a large-flow orbit control jet. By arranging a protrusion at a suitable position on the windward surface of the tail skirt of an aircraft model, the local high pressure induced by the protrusion on the tail skirt provides a pitch torque, which can reduce the impact of orbit control interference and improve the stability of intercepting missiles.

[0040] (2) The present invention determines, through optimized design and a large number of test verifications, that the protrusions are arranged at the position of the surface flow reattachment line on the windward surface of the tail skirt of the aircraft model, so that the protrusions produce favorable control.

[0041] (3) The present invention optimizes the design to determine the angle of the protrusions around the tail skirt of the aircraft model in the circumferential direction as well as the height and width of the protrusions, thereby significantly improving the control efficiency of the protrusions.

[0042] (4) The present invention can directly arrange protrusions on the windward surface of the tail skirt of the aircraft model to control the interference torque as needed, or first use an attitude control engine to perform attitude control jet interference control, and then arrange protrusions on the windward surface of the tail skirt of the aircraft model. The selection can be made according to different situations to achieve effective control of the influence of orbit control interference torque.

[0043] (5) Compared with the attitude control engine control method, the present invention does not require additional energy input, has a simple structure, is easier to implement, and can also be used as a supplement to the attitude control engine control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A flow chart of a control method for reducing the interference torque of a large flow rate track control jet provided by the present invention;

[0045] Figure 2 A schematic diagram of the limiting streamlines on the surface of the jet interference flow field and the arrangement positions of the protrusions provided by the present invention;

[0046] Figure 3 A schematic diagram of the change in pitch moment control efficiency as the height of the protrusion increases provided by the present invention. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0048] like Figure 1 The flow chart of the control method for reducing the interference torque of the large flow track control jet provided by the present invention is as follows:

[0049] (1) Establishing an aircraft model, for example, the model can be established by using 3D solid modeling software such as CATIA. In an optional embodiment, the established aircraft model is a cone-column skirt track control jet model.

[0050] (2) A numerical simulation method is used to obtain the spatial velocity of the jet interference flow field of the aircraft model, the streamlines of the jet interference flow field are obtained according to the spatial velocity, and the limiting streamlines of the aircraft model surface are extracted from the streamlines.

[0051] In an optional embodiment, the jet interference flow field of the aircraft model is obtained by solving the three-dimensional compressible Navier-Stokes equations.

[0052] The three-dimensional compressible Navier-Stokes equations are

[0053]

[0054] in, is a conserved variable, are the inviscid flux vectors in the three directions of the coordinate system x, y, and z, respectively, are the viscous flux vectors in the three directions of x, y, and z in the coordinate system respectively; t is time, x is the flow direction of the coordinate system, y is the normal direction of the coordinate system, and z is the circumferential direction of the coordinate system;

[0055] The coordinate system is defined as follows: a three-dimensional Cartesian rectangular coordinate system is used, with the x-axis along the model flow direction, the y-axis along the normal direction, the z-axis along the circumferential direction, and the coordinate origin O selected as the midpoint of the leading edge of the aircraft model.

[0056] Solving the three-dimensional compressible Navier-Stokes equations, we obtain the conserved variables Then the spatial velocities u, v, and w of the jet interference flow field are obtained.

[0057]

[0058] Where: ρ represents density, u, v, w represent stream velocity, normal velocity and circumferential velocity respectively, and E represents the fluid energy per unit mass.

[0059] In an optional embodiment, the solution can be obtained by commercial fluid simulation software, the time discrete format can adopt LU-SGS, the space discrete format can adopt Roe format, and the turbulence model can adopt SA model.

[0060] (3) Figure 2 The figure shows a schematic diagram of the limiting streamlines on the surface of the jet interference flow field and the arrangement positions of the protrusions provided by the present invention; the surface limiting streamlines of the aircraft model obtained in step (2) are used to obtain the surface flow reattachment line position of the windward surface of the tail skirt of the aircraft model, that is, the arrangement positions of the protrusions.

[0061] (4) The structural form and size of the protrusion can be further optimized so that the control method of the interference torque is optimal. The optimization design of the structural form and size of the protrusion can also be verified or designed by numerical simulation methods.

[0062] In an optional embodiment, the protrusion circumferentially surrounds a portion of the surface of the tail skirt of the aircraft model, and the arc center angle of the surrounding area is 30° to 60°.

[0063] In an optional embodiment, the height h of the protrusion satisfies:

[0064] h / D=0.01~0.1,

[0065] Where: D represents the tail skirt diameter of the aircraft model.

[0066] In an optional embodiment, the width w of the protrusion satisfies:

[0067] w / D=0.01~0.1,

[0068] Where: D represents the tail skirt diameter of the aircraft model.

[0069] The above is a method for controlling the interference torque by arranging protrusions on the windward surface of the tail skirt of an aircraft model when the control torque generated by the protrusions is greater than or equal to the interference torque of the orbit control engine.

[0070] When the control torque generated by the protrusion is smaller than the interference torque of the track control engine, the present invention provides another control method for reducing the interference torque of the large-flow track control jet, which specifically includes:

[0071] (1) First, the attitude control engine is used to perform attitude control jet interference control.

[0072] (2) Arrange a protrusion on the windward surface of the tail skirt of the aircraft model. The specific method is the same as described above for the first case, including:

[0073] (2.1) Establishing an aircraft model, for example, the model can be established by using 3D solid modeling software such as CATIA. In an optional embodiment, the established aircraft model is a cone-column skirt track control jet model.

[0074] (2.2) The numerical simulation method is used to obtain the jet interference flow field of the aircraft model, and the limiting streamlines on the surface of the aircraft model are extracted from the jet interference flow field.

[0075] (2.3) The arrangement position of the protrusion is obtained by using the limiting streamline of the aircraft model surface obtained in step (2.2), that is, the arrangement position of the protrusion is the surface flow reattachment line position of the windward surface of the tail skirt of the aircraft model.

[0076] (2.4) The structural form and size of the protrusion can be further optimized to achieve the best control method for the interference torque.

[0077] Furthermore, the pitch moment control efficiency η, which characterizes the bump control effect, is expressed as follows:

[0078]

[0079] Where: ΔMz 凸起物 represents the pitch disturbance moment caused by the orbital control jet of the bump model, ΔMz represents the pitch disturbance moment caused by the orbital control jet of the no-bump model,

[0080] η = 0 means that the protrusion has no control effect;

[0081] η>0 means that the protrusion produces adverse control;

[0082] -1<η<0 means that the protrusion produces favorable control, and the smaller η is, the higher the control efficiency produced by the protrusion is;

[0083] η=-1 means that the pitch disturbance torque generated by the protrusion completely offsets the adverse effect of the jet interference flow field.

[0084] Example 1

[0085] In this embodiment, a typical cone skirt track control jet model is controlled, with a flight Mach number of 8.0, a flight altitude of 20km, an angle of attack of -4°, a track control jet thrust of 6600N, and a control target of reducing the pitch disturbance torque generated by the track control jet by 20%. After multiple rounds of optimization calculations, Figure 3 The figure shows a schematic diagram of the change in the pitch moment control efficiency as the height of the protrusion increases, provided by an embodiment of the present invention. The protrusion that ultimately meets the design requirements is: h / D=0.05, w / D=0.03, and the circumferential arc center angle is 30°. In this case, the interference torque caused by the track control jet is reduced by 23.16%.

[0086] Where h represents the height of the protrusion, w represents the width of the protrusion, and D represents the diameter of the skirt tail of the projectile.

[0087] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0088] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A control method for reducing the interference torque of a large flow track control jet, characterized in that include, Build an aircraft model. Arrange a protrusion on the windward side of the tail skirt of the aircraft model, or, Firstly, the attitude control engine is used to control the attitude control jet interference, and then a protrusion is arranged on the windward surface of the tail skirt of the aircraft model; The determination of the arrangement position of the protrusions includes: The spatial velocity of the jet interference flow field of the aircraft model is obtained by a numerical simulation method, the streamlines of the jet interference flow field are obtained according to the spatial velocity, and the limiting streamlines of the aircraft model surface are extracted from the streamlines; The surface flow reattachment line position of the windward surface of the tail skirt of the aircraft model is obtained by using the limiting streamline of the aircraft model surface, that is, the arrangement position of the protrusion.

2. The control method for reducing the interference torque of a large flow track control jet according to claim 1 is characterized in that: The spatial velocity of the jet interference flow field of the aircraft model obtained by numerical simulation method includes: The aircraft model is a cone-cylinder skirt trajectory control jet model, and the spatial velocity of the jet interference flow field of the aircraft model is obtained by solving the three-dimensional compressible Navier-Stokes equations.

3. The control method for reducing the interference torque of a large flow track control jet according to claim 2 is characterized in that: The method of obtaining the spatial velocity of the jet interference flow field of the aircraft model by solving the three-dimensional compressible Navier-Stokes equations includes: (1) The three-dimensional compressible Navier-Stokes equations are: in, is a conserved variable, are the inviscid flux vectors in the three directions of the coordinate system x, y, and z, respectively, are the viscous flux vectors in the three directions of x, y, and z in the coordinate system respectively; t is time, x is the flow direction of the coordinate system, y is the normal direction of the coordinate system, and z is the circumferential direction of the coordinate system; The coordinate system is defined as follows: a three-dimensional Cartesian rectangular coordinate system is used, with the x-axis along the model flow direction, the y-axis along the normal direction, the z-axis along the circumferential direction, and the coordinate origin O selected as the midpoint of the leading edge of the aircraft model; (2) Solve the three-dimensional compressible Navier-Stokes equations to obtain the conserved variables The spatial velocities u, v, and w of the jet interference flow field are obtained; u is the stream velocity, v is the normal velocity, and w is the circumferential velocity.

4. The control method for reducing the interference torque of a large flow rate track control jet according to claim 1 is characterized in that: The protrusions circumferentially surround a portion of the surface of the tail skirt of the aircraft model, and the arc center angle of the surrounding area is 30° to 60°.

5. The control method for reducing the interference torque of a large flow rate track control jet according to claim 1 is characterized in that: The height h of the protrusion satisfies: h / D=0.01~0.1, Where: D represents the tail skirt diameter of the aircraft model.

6. The control method for reducing the interference torque of a large flow rate track control jet according to claim 1 is characterized in that: The width w of the protrusion satisfies: w / D=0.01~0.1, Where: D represents the tail skirt diameter of the aircraft model.

7. The control method for reducing the interference torque of a large flow rate track control jet according to claim 1 is characterized in that: When the control torque generated by the protrusion is greater than or equal to the interference torque of the orbit control engine, the protrusion is arranged on the windward surface of the tail skirt of the aircraft model to control the interference torque; When the control torque generated by the protrusion is smaller than the interference torque of the orbit control engine, the attitude control engine is first used to perform attitude control jet interference control, and then the protrusion is arranged on the windward surface of the tail skirt of the aircraft model.

8. The control method for reducing the interference torque of a large flow rate track control jet according to claim 1 is characterized in that: The pitch moment control efficiency η, which characterizes the bump control effect, is expressed as follows: Where: ΔMz 凸起物 represents the pitch disturbance moment caused by the orbital control jet of the bump model, ΔMz represents the pitch disturbance moment caused by the orbital control jet of the bump-free model, η = 0 means that the protrusion has no control effect; η>0 means that the protrusion produces adverse control; -1<η<0 means that the protrusion produces favorable control, and the smaller η is, the higher the control efficiency produced by the protrusion is; η=-1 means that the pitch disturbance torque generated by the protrusion completely offsets the adverse effect of the jet interference flow field.

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