Aircraft pressure center regulating device and regulating method and design method thereof

Abstract

The present application relates to an aircraft pressure center adjustment device and its adjustment method and design method, which include obtaining the length and minimum cross-sectional size of the internal space of the tail compartment of the aircraft; determining the initial length and initial cross-sectional size of the initial telescopic section based on the length and minimum cross-sectional size; setting a avoidance space corresponding to the internal mechanism on the initial telescopic section according to the internal mechanism of the internal space of the tail compartment of the aircraft, obtaining the cross-sectional shape of the initial telescopic section, and forming initial parameters in combination with the initial length and initial cross-sectional size; based on the initial parameters, verifying and analyzing the aerodynamic performance of the initial telescopic section to obtain a telescopic section that meets the requirements. In order to improve stability, the telescopic section extends outward from the tail of the aircraft, and the pressure center and aerodynamic focus of the aircraft move backward; in order to improve maneuverability, the telescopic section shrinks inward from the tail of the aircraft, and the pressure center and aerodynamic focus of the aircraft move forward, so as to solve the problems caused by the way of changing the center of mass to deal with the pressure center change.

Description

Technical Field

[0001] The present application relates to the field of aerodynamic layout design, and in particular to an aircraft pressure center adjustment device and an adjustment method and a design method thereof. Background Art

[0002] At present, aircraft are affected by aerodynamic forces during flight, among which both normal force and axial force will cause pitch moment on the aircraft; for conventional shape aircraft, the axial force is generally one order of magnitude or more smaller than the normal force, and the force arm of the axial force to the center of mass is much smaller than the force arm of the normal force to the center of mass, so the contribution of the axial force to the pitch moment is secondary, so for conventional layout aircraft, the position of the aircraft's pressure center can be approximated using conventional calculation formulas. And when the angle of attack is not large, the point where the total lift acts on the longitudinal axis is often approximated as the aircraft's pressure center.

[0003] In some existing technologies, most aircraft adopt a fixed aerodynamic shape. When the flight speed range and attitude span of the aircraft are large, the range of change of its center of pressure is also large. Generally, the requirements of aircraft stability are met, and its controllability will be reduced.

[0004] In the past, a solution of variable center of mass has been proposed to solve this problem. Since the center of mass coefficient of traditional aircraft is a fixed value, when designing the axial center of mass balancing, a center of mass adjustment block installation interface is usually designed as far forward as possible in the axial direction. The center of mass coefficient of the verifier can be adjusted by changing the mass of the center of mass adjustment block. However, in the actual implementation process, the variable center of mass will occupy a large amount of internal space of the aircraft, and the effective loading space will be significantly reduced. Summary of the invention

[0005] The embodiments of the present application provide an aircraft center of pressure adjustment device and an adjustment method and design method thereof, so as to solve the problem that the method of solving the center of pressure change by changing the center of mass in the related art will occupy a large amount of internal space of the aircraft and significantly reduce the effective filling space during actual implementation.

[0006] In a first aspect, a method for designing an aircraft center of pressure regulating device is provided, which comprises the following steps:

[0007] Obtain the length and minimum cross-sectional dimensions of the interior space of the tail compartment of the aircraft;

[0008] Determining an initial length and an initial cross-sectional dimension of the initial telescopic section based on the length and the minimum cross-sectional dimension;

[0009] According to the internal structure of the internal space of the tail compartment of the aircraft, an avoidance space corresponding to the internal structure is set on the initial telescopic section to obtain the cross-sectional shape of the initial telescopic section; and initial parameters are formed by combining the cross-sectional shape, the initial length and the initial cross-sectional size;

[0010] Based on the initial parameters, verify and analyze the aerodynamic performance of the initial telescopic section to obtain target parameters that meet design requirements;

[0011] The telescopic section is manufactured according to the target parameters.

[0012] In some embodiments, after obtaining the initial parameters that meet the design requirements, the following steps are also included:

[0013] Based on the internal space of the tail compartment of the aircraft, initial parameters that meet the design requirements, and the internal mechanism, obtaining the installation space of the drive mechanism;

[0014] Based on the installation space, the structural dimensions of the driving mechanism are determined and manufactured.

[0015] In some embodiments, the aerodynamic performance of the initial telescopic section is verified and analyzed, comprising the following steps:

[0016] Based on the initial parameters, CFD simulation calculation is performed to obtain calculation results;

[0017] comparing the calculated results with a set standard;

[0018] If the calculated result is greater than the set value, the initial parameter is used as the target parameter;

[0019] Otherwise, the initial parameters are adjusted, and the step of performing CFD simulation calculation based on the initial parameters to obtain calculation results is repeated.

[0020] In some embodiments, the aerodynamic performance verification analysis includes aerodynamic performance verification analysis of the initial telescopic section contraction state;

[0021] The set value corresponding to the aerodynamic performance verification analysis of the initial telescopic section contraction state is static stability.

[0022] In some embodiments, the aerodynamic performance verification analysis includes an aerodynamic performance verification analysis of an initial telescopic section extended state;

[0023] The set value corresponding to the aerodynamic performance verification analysis of the initial telescopic section extended state is the static stability of the aircraft.

[0024] In some embodiments, the aircraft is an iso-rectirotating body aircraft or an aircraft with a cone angle body.

[0025] In a second aspect, an aircraft center of pressure regulating device is provided, comprising:

[0026] The telescopic section is manufactured according to the design method of the aircraft pressure center regulating device.

[0027] In some embodiments, a driving mechanism for driving the telescopic section is also included.

[0028] In a third aspect, a method for adjusting an aircraft center of pressure adjustment device is provided, comprising the following steps:

[0029] Installing the aircraft center of pressure regulating device in the interior space of the tail compartment of the aircraft;

[0030] Obtain the aircraft's requirements for stability and maneuverability, and make corresponding adjustments based on the requirements.

[0031] In some embodiments, the aircraft pressure center adjustment device further includes a driving mechanism for driving the telescopic section; when the requirement is to improve stability, the driving mechanism is used to drive the telescopic section to extend outward from the tail of the aircraft, so that the pressure center and aerodynamic focus of the aircraft move backward;

[0032] When the demand is to improve maneuverability, the drive mechanism is used to drive the telescopic section to retract inward from the tail of the aircraft, so that the pressure center and the aerodynamic focus of the aircraft move forward.

[0033] The beneficial effects of the technical solution provided by this application include:

[0034] The embodiment of the present application provides an aircraft pressure center adjustment device and its adjustment method and design method. According to the length and minimum cross-sectional size of the internal space of the tail compartment of the aircraft, the initial length and initial cross-sectional size of the initial telescopic section are determined; then, an avoidance space corresponding to the internal mechanism is set on the initial telescopic section to obtain the cross-sectional shape of the initial telescopic section, thereby obtaining the initial parameters; the aerodynamic performance is verified and analyzed according to the initial parameters, thereby obtaining the target parameters that meet the design requirements, thereby obtaining the size of the final telescopic section. When the telescopic section extends outward from the tail of the aircraft, the pressure center and aerodynamic focus of the aircraft move backward to meet the stability requirements; when the telescopic section retracts inward from the tail of the aircraft, the pressure center and aerodynamic focus of the aircraft move forward to meet the maneuverability requirements; when the above requirements are met, the internal space of the tail compartment of the aircraft is effectively utilized to solve the problems caused by the method of solving the pressure center change by changing the center of mass. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of an iso-recti-rotating adult aircraft provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of a telescopic section provided in an embodiment of the present application being extended from an iso-recti-rotating adult aircraft;

[0038] Figure 3 A schematic diagram of an aircraft with a cone-shaped body provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of a telescopic section provided in an embodiment of the present application extending from a main body aircraft with a tapered angle;

[0040] Figure 5 A schematic diagram of a canard-type aerodynamically configured isotropic aircraft provided in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of a telescopic section provided in an embodiment of the present application being extended from a canard-type aerodynamically configured isotropic aircraft;

[0042] Figure 7 A schematic flow chart of a design method for an aircraft center of pressure regulating device provided in an embodiment of the present application.

[0043] In the figure: 1. Aircraft; 2. Initial telescopic section. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0045] The embodiments of the present application provide an aircraft center of pressure adjustment device and an adjustment method and design method thereof, so as to solve the problem that the method of solving the center of pressure change by changing the center of mass in the related art will occupy a large amount of internal space of the aircraft and significantly reduce the effective filling space during actual implementation.

[0046] See also Figure 1-Figure 7 , a design method for an aircraft pressure center regulating device, comprising the following steps:

[0047] S01. Obtain the length and minimum cross-sectional dimensions of the interior space of the tail compartment of the aircraft 1;

[0048] S02. Determine the initial length and initial cross-sectional size of the initial telescopic section 2 based on the length and the minimum cross-sectional size;

[0049] S03, obtaining the internal structure of the internal space of the tail compartment of the aircraft 1, setting an avoidance space corresponding to the internal structure on the initial telescopic section 2, so as to obtain the cross-sectional shape of the initial telescopic section 2; combining the cross-sectional shape, the initial length and the initial cross-sectional size to form initial parameters;

[0050] S04-S05, based on the initial parameters, verify and analyze the aerodynamic performance of the initial telescopic section 2 to obtain target parameters that meet the design requirements;

[0051] S06. Manufacturing the telescopic section according to the target parameters.

[0052] The telescopic section manufactured through the above steps can make the pressure center and aerodynamic focus of the aircraft 1 move backward when the telescopic section is extended outward from the tail of the aircraft 1, thereby meeting the stability requirement and improving the stability; and can make the pressure center and aerodynamic focus of the aircraft 1 move forward when the telescopic section is retracted inward from the tail of the aircraft 1, thereby meeting the maneuverability requirement and improving the maneuverability; when the above requirements are met, the internal space of the tail cabin section of the aircraft 1 is effectively utilized to solve the problems caused by the method of changing the center of mass to deal with the change of the center of pressure.

[0053] This can meet the requirements of different flight Mach numbers or angles of attack for the maneuverability or stability of the aircraft 1; the final telescopic section is suitable for supersonic and hypersonic aircraft 1 under various layouts.

[0054] In some preferred embodiments, after obtaining the initial parameters that meet the design requirements, the following steps are also included:

[0055] Based on the internal space of the tail compartment of the aircraft 1, the initial parameters that meet the design requirements and the internal structure, the installation space of the driving mechanism is obtained; based on the installation space, the structural dimensions of the driving mechanism are determined and manufactured.

[0056] The telescopic section is constrained by a guide rail, and the drive mechanism uses gear transmission or telescopic motor transmission to drive the inner cavity to reciprocate, and the structure is relatively easy to implement. After determining the telescopic section, the detailed structural design of the drive mechanism can be carried out. In addition to the structure of the telescopic section itself and the drive mechanism, it will not occupy too much space inside the aircraft.

[0057] In some preferred embodiments, steps S04-S05 are specifically to verify and analyze the aerodynamic performance of the initial telescopic section 2, including the following steps:

[0058] Based on the initial parameters, CFD simulation calculation is performed to obtain calculation results;

[0059] comparing the calculated results with a set standard;

[0060] If the calculated result is greater than the set value, the initial parameter is used as the target parameter;

[0061] Otherwise, the initial parameters are adjusted, and the step of performing CFD simulation calculation based on the initial parameters to obtain calculation results is repeated.

[0062] The aerodynamic performance verification and analysis includes the aerodynamic performance verification and analysis of the initial telescopic section 2 in the retracted state; the set value corresponding to the aerodynamic performance verification and analysis of the initial telescopic section 2 in the retracted state is the static stability. The aerodynamic performance verification and analysis includes the aerodynamic performance verification and analysis of the initial telescopic section 2 in the extended state; the set value corresponding to the aerodynamic performance verification and analysis of the initial telescopic section 2 in the extended state is the static stability of the aircraft.

[0063] In some preferred embodiments, the aircraft 1 is an iso-rectangular-rotating aircraft or an aircraft with a cone-angle body. Specific implementation methods are given below:

[0064] Example 1, reference Figure 1 and Figure 2 .

[0065] Take the conventional straight-rotating aircraft with tail rudder control as an example. Figure 1 First, a cavity is used on the initial telescopic section 2 to avoid the area of ​​the four servos; the initial length of the initial telescopic section 2 is initially determined to be 1 / 4 of the total length; since the aircraft body is an equal straight section structure, the initial cross-sectional size and cross-sectional shape of the initial telescopic section 2, after avoiding the servos and considering the thickness of the aircraft surface structure, are as follows Figure 2 As shown; then the aerodynamic performance of the initial telescopic section 2 in the contracted state and the fully extended state is calculated through CFD simulation, and the comparison between the two is shown in Table 1; from the calculation comparison, it can be seen that when the inner cavity is fully extended, the static stability of the aircraft can be improved by 4.5% to 8.3%, and the adjustment effect is very obvious.

[0066] If the original aerodynamic shape is used, in order to ensure the static stability at a small angle of attack of Mach 7, the center of mass of the aircraft needs to be designed to be 0.45 or even further forward. In this way, when the aircraft flies below Mach 5, since its center of pressure at a large angle of attack is far back, the static stability reaches 8%, and it is difficult to pull up to fly at a larger angle of attack, and the control characteristics and maneuverability are significantly poor. If the telescopic section design method provided by the present invention is adopted, the tail 8 traveler can be retracted when flying at Mach 7, and the telescopic inner cavity can be retracted when flying below Mach 5, so that the aircraft can be pulled up to a larger angle of attack, and the static stability is only 0-3%, and its control performance and maneuverability are significantly improved.

[0067]

[0068] Table 1 Comparison of the pressure center position in the retracted and extended states of the telescopic section in Example 1

[0069] Example 2, reference Figure 3 and Figure 4 .

[0070] If the aircraft 1 does not use a straight section body, but Figure 3 The tapered main body aircraft shown in the figure can also use this method to design the telescopic section. The steps are the same as those in Example 1, except that the cross-sectional size of the telescopic inner cavity will be reduced according to the taper. The minimum cross-sectional size of the internal space is used as the initial cross-sectional size, and the obtained Figure 4 The telescopic section shape is shown in the figure. The aerodynamic performance comparison of the telescopic section in the contracted state and the fully extended state calculated by CFD simulation is shown in Table 2. It can be seen that for the aircraft with a cone angle, the adjustment effect of the telescopic section on the pressure center is 1.2% to 5.3%, which is not as obvious as the straight section aircraft, but it can still improve the stability of the aircraft to a certain extent.

[0071]

[0072] Table 2 Comparison of the pressure center position in the retracted and extended states of the telescopic section in Example 2

[0073] Application example: For a canard-type aerodynamic layout of an isotropic aircraft, the tail only has a stabilizer but no control mechanism. Therefore, the cross section of the telescopic section can be directly used as the cross section of the aircraft itself minus the structural thickness. Figure 5 and Figure 6 As shown, after adopting the telescopic section design, the internal space loss is small.

[0074] The present application also proposes an aircraft pressure center regulating device, which comprises:

[0075] The telescopic section manufactured according to the design method of the aircraft center of pressure regulating device also includes a driving mechanism for driving the telescopic section.

[0076] The present application also proposes a method for adjusting an aircraft center of pressure adjustment device, which comprises the following steps:

[0077] The aircraft center of pressure regulating device described above is installed in the interior space of the tail compartment of the aircraft 1; the requirements of the aircraft 1 for stability and maneuverability are obtained, and corresponding adjustments are made according to the requirements.

[0078] When the requirement is to improve stability, the driving mechanism is used to drive the telescopic section to extend outward from the tail of the aircraft 1 so that the pressure center and the aerodynamic focus of the aircraft 1 move backward;

[0079] When the demand is to improve the maneuverability, the driving mechanism is used to drive the telescopic section to retract inward from the tail of the aircraft 1, so that the pressure center and the aerodynamic focus of the aircraft 1 move forward.

[0080] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0081] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0082] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A design method for an aircraft pressure center regulating device, It is characterized in that It includes the following steps: Obtaining the length and minimum cross-sectional dimensions of the interior space of the tail compartment of the aircraft (1); Based on the length and the minimum cross-sectional dimension, determining the initial length and the initial cross-sectional dimension of the initial telescopic section (2); According to the internal structure of the internal space of the tail compartment of the aircraft (1), an avoidance space corresponding to the internal structure is provided on the initial telescopic section (2) to obtain the cross-sectional shape of the initial telescopic section (2); and initial parameters are formed by combining the cross-sectional shape, initial length and initial cross-sectional size; Based on the initial parameters, verifying and analyzing the aerodynamic performance of the initial telescopic section (2) to obtain target parameters that meet design requirements; The telescopic section is manufactured according to the target parameters.

2. The design method of the aircraft center of pressure regulating device according to claim 1, It is characterized in that After obtaining the initial parameters that meet the design requirements, the following steps are also included: Based on the internal space of the tail compartment of the aircraft (1), initial parameters that meet design requirements, and internal mechanisms, obtaining installation space for the drive mechanism; Based on the installation space, the structural dimensions of the driving mechanism are determined and manufactured.

3. The design method of the aircraft center of pressure regulating device according to claim 1, It is characterized in that The aerodynamic performance of the initial telescopic section (2) is verified and analyzed, comprising the following steps: Based on the initial parameters, CFD simulation calculation is performed to obtain calculation results; comparing the calculated results with a set standard; If the calculated result is greater than the set value, the initial parameter is used as the target parameter; Otherwise, the initial parameters are adjusted, and the step of performing CFD simulation calculation based on the initial parameters to obtain calculation results is repeated.

4. The design method of the aircraft center of pressure regulating device as claimed in claim 3, Features: The aerodynamic performance verification and analysis includes the aerodynamic performance verification and analysis of the initial telescopic section (2) in a contracted state; The set value corresponding to the aerodynamic performance verification analysis of the initial telescopic section (2) in the contracted state is the static stability.

5. The design method of the aircraft center of pressure regulating device as claimed in claim 3, Features: The aerodynamic performance verification and analysis includes the aerodynamic performance verification and analysis of the initial telescopic section (2) in an extended state; The set value corresponding to the aerodynamic performance verification analysis of the initial telescopic section (2) in the extended state is the static stability of the aircraft.

6. The design method of the aircraft center of pressure regulating device according to claim 1, Features: The aircraft (1) is an iso-rectirotating body aircraft or an aircraft with a cone-angle body.

7. An aircraft pressure center regulating device, It is characterized in that It includes: A telescopic section manufactured according to the design method of an aircraft center of pressure regulating device as claimed in claim 1.

8. The aircraft center of pressure regulating device according to claim 7, Features: Also included is a driving mechanism for driving the telescopic section.

9. A method for adjusting a pressure center adjusting device of an aircraft, It is characterized in that It includes the following steps: Installing the aircraft center of pressure regulating device as claimed in claim 7 in the interior space of the tail compartment of the aircraft (1); Obtain the requirements of the aircraft (1) for stability and maneuverability, and make corresponding adjustments based on the requirements.

10. The method for adjusting the aircraft center of pressure adjustment device according to claim 9, Features: The aircraft center of pressure regulating device also includes a driving mechanism for driving the telescopic section; When the need is to improve stability, the drive mechanism is used to drive the telescopic section to extend outward from the tail of the aircraft (1), so that the pressure center and the aerodynamic focus of the aircraft (1) move backward; When the need is to improve maneuverability, the drive mechanism is used to drive the telescopic section to retract inward from the tail of the aircraft (1), so that the pressure center and the aerodynamic focus of the aircraft (1) move forward.

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