Control plane upper rotating shaft design method considering lift augmentation target and drag reduction capacity

Abstract

The invention belongs to the field of aerodynamic layout design of aircraft control surfaces, and relates to a control surface upper rotating shaft design method giving consideration to a lift augmentation target and drag reduction ability, which comprises the following steps of: performing integrated fusion design on an actuator cylinder bump and a wing lower surface, obtaining a current position of a control surface rotating shaft and a distance L1 from the control surface rotating shaft to the wing lower surface, and determining an adjustable range of the control surface rotating shaft; and performing iterative simulation calculation, and setting proper criteria to obtain a group of simulation data with optimal comprehensive evaluation as the final position of the control surface rotating shaft and the final contour of the actuator cylinder bump. Through the optimal design of the upper and lower positions of the rotating shaft, the supersonic resistance is reduced by 50% compared with the traditional lower rotating shaft design, the aerodynamic layout design contradiction under multiple design constraints is relieved to a certain extent, the control surface rotating shaft design method can be popularized to other aircraft control surface rotating shaft design, and the aircraft performance is improved.

Description

Technical Field

[0001] The present application belongs to the field of aerodynamic layout design of aircraft control surfaces, and in particular relates to a design method for a rotating shaft on a control surface that takes into account both lift increase goals and drag reduction capabilities. Background Art

[0002] In the aerodynamic layout design of aircraft control surfaces, one of the main goals of aircraft design is to increase lift as much as possible and reduce drag to the greatest extent through the optimization of design parameters. As an important lift-increasing component, the wing control surface adopts simple flaps or retreating flaps to increase the effective area of ​​the control surface deflection. The rotation axis of the control surface usually adopts a lower rotation axis design close to the lower surface, which can further increase the effective deflection and effective deflection area of ​​the control surface to achieve the purpose of increasing lift. However, the lower rotation axis usually requires additional cost. On the third-generation aircraft with thicker wing profiles, the lower rotation axis realizes the deflection of the control surface through several sets of exposed hinges, or adopts a larger actuator bulge to envelop the actuator. The above designs will pay a greater resistance cost and will reduce a certain stealth performance.

[0003] The design of the rudder shaft of an advanced stealth, high-performance fourth-generation aircraft provides sufficient installation structure space for the actuator by designing the actuator bulge under the condition of a certain airfoil space at the shaft. The aspect ratio of the actuator bulge is reduced by optimizing the height of the shaft, in the hope of reducing resistance and improving stealth. However, this will result in a certain loss of trim lift. Therefore, under multiple design constraints, the key to solving design contradictions is to carry out an optimized compromise design of the shaft of the lift-enhancing rudder. Summary of the invention

[0004] The purpose of the present application is to provide a method for designing a rotating shaft on a rudder surface that takes into account both the lift-increasing target and the drag-reducing capability, so as to solve the problem in the prior art that the rudder surface rotating shaft design will lose the trim lift.

[0005] The technical solution of the present application is: a method for designing a rotating shaft on a rudder surface that takes into account both the lift increase target and the drag reduction capability, comprising:

[0006] The actuator drum is integrated with the lower surface of the wing to obtain the current position of the rudder shaft and the distance L1 from the rudder shaft to the lower surface of the wing, and the adjustable range of the rudder shaft is determined. The lowest position in the adjustable range is the current position of the rudder shaft, and the highest position is the position on the upper surface of the wing.

[0007] The position of the rudder shaft is moved upward according to the adjustment step length, and then the contour of the actuator bulge is re-determined according to the adjusted rudder shaft position and the bottom parameters of the current actuator, and then a simulation calculation is performed to determine the aerodynamic characteristics under the current state;

[0008] Obtain assessment requirements, including angle of attack trim lift requirements, transonic drag requirements, and stealth feature requirements, obtain simulation data, and determine whether the aerodynamic characteristics in the current state meet the assessment requirements. If so, save the simulation data; if not, discard the simulation data;

[0009] Adjust the step size to perform simulation calculation again, collect simulation data and judge again whether it meets the assessment requirements; and at the same time judge whether the current position of the rudder shaft reaches the upper limit of the adjustable range. If not, perform simulation calculation again; if yes, complete all simulation calculations and obtain all saved simulation data;

[0010] Comprehensively analyze the impact of all saved simulation data on trim lift, transonic drag and stealth characteristics, and obtain a set of simulation data with the best comprehensive evaluation as the final position of the rudder shaft and the final contour of the actuator bulge.

[0011] Preferably, the method for comprehensive analysis is as follows: by obtaining the trim lift and the trim lift assessment requirements; the transonic drag reduction and the transonic drag assessment requirements; the stealth characteristic gain and the stealth characteristic assessment requirements; performing mathematical expectation calculation or mean square error calculation, and taking the set of simulation data with the highest score as the final position of the rudder shaft and the final contour of the actuator bulge.

[0012] Preferably, the adjustment step is set to 25 mm.

[0013] Preferably, the height of the actuator cylinder bulge is greater than or equal to 80 mm.

[0014] Preferably, the width of the actuator cylinder bulge is greater than or equal to 680 mm.

[0015] Preferably, the aerodynamic characteristics include wing trim lift, transonic drag and stealth characteristic data.

[0016] The present application discloses a method for designing a rotating shaft on a rudder surface that takes into account both the lift-increasing target and the drag-reducing capability. By optimizing the design of the upper and lower positions of the rotating shaft, the supersonic drag is reduced by 50% relative to the traditional lower rotating shaft design. This alleviates the aerodynamic layout design contradictions under multiple design constraints to a certain extent. The method for designing a rotating shaft on a rudder surface can be extended to the design of rotating shafts on rudder surfaces of other aircraft to improve aircraft performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0018] Figure 1 This is a schematic diagram of the overall process of this application;

[0019] Figure 2This is a schematic diagram of the design of the rudder shaft at the trailing edge of the aircraft in this application.

[0020] 1. Lower surface of wing; 2. Bulge of actuator cylinder. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] A design method for the rotation axis of the rudder surface that takes into account both the goal of increasing lift and the ability to reduce drag is proposed. Analysis shows that the traditional design method loses about 0.3% of the trim lift, increases the transonic drag by 2%, and reduces the stealth by 1.5%, which has a significant adverse effect on the performance and stealth of the platform. It is necessary to perform parametric design of the rotation axis position of the rudder surface of the trailing edge flap in order to improve the aircraft platform capability.

[0023] like Figure 1 As shown, the specific design is as follows:

[0024] Step S100, the actuator drum 2 is integrated with the wing lower surface 1 to obtain the current position of the rudder shaft and the distance L1 from the rudder shaft to the wing lower surface 1, such as Figure 2 , determine the adjustable range of the rudder shaft, the lowest position in the adjustable range is the current rudder shaft position, and the highest position is the upper surface position of the wing; set the adjustment step length, such as 5mm, 10mm, etc.; preferably, the adjustment step length is set to 25mm. The height of the actuator drum 2 is greater than or equal to 80mm, and the width is greater than or equal to 680mm. The current position of the actuator drum 2 is as follows Figure 2 As shown in ①.

[0025] Step S200, the position of the rudder shaft is moved upward according to the adjustment step length, and the position of the actuator is also adjusted upward accordingly, and then the contour of the actuator bulge 2 is re-determined according to the adjusted rudder shaft position and the bottom parameters of the current actuator, and then a simulation calculation is performed to determine the aerodynamic characteristics in the current state, including wing trim lift, transonic drag and stealth characteristic data;

[0026] Step S300, obtaining assessment requirements, including angle of attack trim lift requirements, transonic drag requirements, and stealth feature requirements, obtaining simulation data and determining whether the aerodynamic characteristics in the current state meet the assessment requirements, if so, saving the simulation data; if not, discarding the simulation data;

[0027] Step S400, adjust the step size to perform simulation calculation again, collect simulation data and determine again whether it meets the assessment requirements; and at the same time determine whether the current position of the rudder shaft reaches the upper limit of the adjustable range. If not, complete all simulation calculations; if so, stop the simulation calculation and obtain all saved simulation data.

[0028] Step S500, comprehensively analyze the influence of all the saved simulation data on the trim lift, transonic drag and stealth characteristics, and obtain a set of simulation data with the best comprehensive evaluation as the final position of the rudder shaft and the final contour of the actuator drum 2. The final contour of the actuator drum 2 is as follows: Figure 2 As shown in ②. Preferably, the comprehensive analysis method can adopt the mathematical expectation calculation method or the mean square error calculation method, by obtaining the trim lift and the trim lift assessment requirements; the transonic drag reduction and the transonic drag assessment requirements; the stealth characteristic gain and the stealth characteristic assessment requirements; performing mathematical expectation calculation or mean square error calculation, and taking the set of simulation data with the highest score as the final position of the rudder shaft and the final contour of the actuator drum 2.

[0029] In a specific embodiment, two optimization schemes of moving the rudder shaft up by 25mm and 50mm are used to comprehensively analyze the impact on the balanced lift, transonic drag and stealth characteristics; at this time, the rudder shaft is moved up to meet the requirements of the angle of attack balanced lift assessment; the transonic drag is reduced by 50%, and the maneuverability is greatly improved; the forward stealth characteristic is increased by 0.9%, meeting the design requirements.

[0030] This design method reduces supersonic drag by 50% compared with the traditional lower shaft design through optimized design of the upper and lower shaft positions, which to a certain extent alleviates the aerodynamic layout design contradictions under multiple design constraints. The design method of the upper shaft of the rudder surface can be extended to the shaft design of the rudder surfaces of other aircraft to improve aircraft performance.

[0031] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0032] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A design method for the rotating shaft on the rudder surface that takes into account both the lift increase target and the drag reduction capability. It is characterized in that include: The actuator drum (2) is integrated with the lower surface (1) of the wing to obtain the current position of the rudder shaft and the distance L1 from the rudder shaft to the lower surface (1) of the wing, and the adjustable range of the rudder shaft is determined, wherein the lowest position in the adjustable range is the current position of the rudder shaft and the highest position is the position of the upper surface of the wing; The position of the rudder surface shaft is moved upward according to the adjustment step length, and then the contour of the actuator cylinder bulge (2) is re-determined according to the adjusted rudder surface shaft position and the bottom parameters of the current actuator cylinder, and then a simulation calculation is performed to determine the aerodynamic characteristics under the current state; Obtain assessment requirements, including angle of attack trim lift requirements, transonic drag requirements, and stealth feature requirements, obtain simulation data, and determine whether the aerodynamic characteristics in the current state meet the assessment requirements. If so, save the simulation data; if not, discard the simulation data; Adjust the step size to perform simulation calculation again, collect simulation data and judge again whether it meets the assessment requirements; and at the same time judge whether the current position of the rudder shaft reaches the upper limit of the adjustable range. If not, perform simulation calculation again; if yes, complete all simulation calculations and obtain all saved simulation data; The influence of all the saved simulation data on the trim lift, transonic drag and stealth characteristics is comprehensively analyzed, and a set of simulation data with the best comprehensive evaluation is obtained as the final position of the rudder shaft and the final contour of the actuator drum (2).

2. The method for designing a rotating shaft on a rudder surface that takes into account both the lift increase target and the drag reduction capability as claimed in claim 1, It is characterized in that The specific method of comprehensive analysis is: by obtaining the trim lift and trim lift assessment requirements; transonic drag reduction and transonic drag assessment requirements; stealth characteristic benefits and stealth characteristic assessment requirements; Mathematical expectation calculation or mean square error calculation is performed, and the set of simulation data with the highest score is used as the final position of the rudder shaft and the final contour of the actuator drum (2).

3. The method for designing a rotating shaft on a rudder surface that takes into account both the lift increase target and the drag reduction capability as claimed in claim 1, Features: The adjustment step length is set to 25 mm.

4. The method for designing a rotating shaft on a rudder surface that takes into account both the lift increase target and the drag reduction capability as claimed in claim 1, Features: The height of the actuating cylinder bulge (2) is greater than or equal to 80 mm.

5. The method for designing a rotating shaft on a rudder surface that takes into account both the lift increase target and the drag reduction capability as claimed in claim 1, Features: The width of the actuating cylinder bulge (2) is greater than or equal to 680 mm.

6. The method for designing a rotating shaft on a rudder surface that takes into account both the lift increase target and the drag reduction capability as claimed in claim 1, Features: The aerodynamic characteristics include wing trim lift, transonic drag and stealth characteristics data.

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