A method for correcting static aeroelastic effects of a full-body model of a high-aspect-ratio aircraft

Abstract

The present invention belongs to the technical field of aircraft design, and specifically relates to a method for correcting the static aeroelastic influence of a full-machine model of a large aspect ratio aircraft. The method for correcting the static aeroelastic influence of a full-machine model of a large aspect ratio aircraft of the present invention comprises making a rigid model and an elastic model; conducting a wind tunnel test; obtaining the static aeroelastic influence amount; and correcting the aerodynamic coefficient. The method for correcting the static aeroelastic influence of a full-machine model of a large aspect ratio aircraft of the present invention takes into account the influence of the elastic deformation of the aircraft structure, and corrects the static aeroelastic influence of the wind tunnel test data. The correction accuracy is higher than that of the static aeroelastic influence correction method based on engineering calculations or numerical simulations. It is not only applicable to the frame configuration, but also to the cruise configuration. The corrected test data is used for the design of the flight control law of the aircraft, which meets the demand for correction of the correlation between the aircraft's ground and earth data, saves the test cycle and funds, and has engineering practical value.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft design, and in particular relates to a method for correcting static aeroelastic effects of a full-machine model of a large-aspect-ratio aircraft. Background Art

[0002] The static aeroelastic effect of an aircraft can significantly alter the load distribution on its wing or control surfaces, and is therefore of great significance to aircraft design. Underestimating this effect can, at best, reduce aerodynamic performance, impacting flight economy and comfort, and, at worst, lead to wing divergence or control counter-effects, potentially causing flight safety accidents. Conventional wind tunnel test models do not simulate the elastic characteristics of real aircraft and do not account for static aeroelastic effects. This makes it impossible to obtain aerodynamic characteristic data after elastic deformation under real flight conditions. Obtaining structural elastic deformation and its effects is one of the most significant differences between wind tunnel testing and real flight.

[0003] To improve aerodynamic and structural efficiency, the aerodynamic and structural layouts adopted by new aircraft generally have the following typical characteristics: ① To improve aerodynamic efficiency and achieve a higher lift-to-drag ratio, the wing aspect ratio is usually large. The aspect ratio of traditional large aircraft wings is generally around 7, while the aspect ratio of modern advanced large aircraft has increased to around 8-10. The aspect ratio of the wings of high-altitude, long-endurance unmanned aerial vehicles (UAVs) can even reach 35. UAVs have a cruising altitude of 18,000 to 20,000 meters and a maximum flight time of 10 hours. ② To reduce shock wave drag and increase the cruise Mach number, supercritical swept wings are often used. The quarter-chord sweep angle of modern advanced large aircraft wings is typically 25° to 35°. ③ To reduce the structural weight of the wings themselves and improve their effective load-bearing capacity, modern advanced large aircraft utilize a large number of new composite materials with higher specific stiffness and strength. The wing's internal beams, ribs, and external skins are also becoming increasingly thinner and lighter, resulting in ever-increasing structural efficiency. The wings of high-altitude, long-endurance drones, for example, have a spanwise weight of less than 1 kg / m, exhibiting high flexibility and generating static aeroelastic deformations of up to 25% of the wing's half-span. Furthermore, most new aircraft possess transonic or even near-sonic cruise capabilities, and high-aspect-ratio cruise missiles require high-speed, ground-skimming flight, placing even more stringent aerodynamic loads on the wings. Consequently, the common challenges faced by new aircraft are: high aspect ratios, low structural mass, high flight speeds, and high load-bearing requirements, leading to significant static aeroelasticity issues.

[0004] Static aeroelastic effects have a significant impact on the overall structure, aerodynamics, structure, and control systems of an aircraft, playing a key role in improving aircraft design. New aircraft design emphasizes the concept of "no-penalty design." For subsonic aircraft, every 1% reduction in structural weight increases payload by 1-2%, while for supersonic aircraft, the increase is 4%. Therefore, static aeroelastic effects must be considered as an influencing factor in the initial design phase of new aircraft and studied as a major issue affecting the overall design of new aircraft.

[0005] Currently, there is an urgent need to develop a method for correcting the static aeroelastic effects of the full-aircraft model of a large aspect ratio aircraft. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for correcting the static aeroelastic effect of a full-machine model of a large aspect ratio aircraft, so as to overcome the defects of the prior art.

[0007] The static aeroelastic influence correction method for the full-aircraft model of a large aspect ratio aircraft of the present invention is based on the principle of linear superposition. The static aeroelastic influence quantity is regarded as a part of the aerodynamic coefficient and converted into a dimensionless parameter. The same regularization method is adopted as the aircraft's baseline aerodynamic coefficient, dynamic influence quantity, and Reynolds number effect influence quantity. It can be well matched and applied to the correction of the aerodynamic characteristic correlation of wind tunnel test data. Regardless of whether the rigid model is based on a frame configuration or a cruise configuration, the correction can be achieved, which solves the problem that the traditional static aeroelastic influence correction requires that the rigid model must be based on a frame configuration.

[0008] The method for correcting the static aeroelastic effect of a full-machine model of a high-aspect-ratio aircraft of the present invention comprises the following steps:

[0009] S10. Create a rigid model and an elastic model;

[0010] S20. Conduct wind tunnel tests;

[0011] Conduct wind tunnel tests on rigid models to obtain the aerodynamic coefficients of the rigid models;

[0012] Conduct wind tunnel tests on elastic models to obtain aerodynamic coefficients of the elastic models;

[0013] S30. Obtaining static aeroelastic influence;

[0014] Under each flight state, the static aeroelastic influence ΔA under each flight state is obtained according to the static aeroelastic influence = elastic model aerodynamic coefficient - rigid model aerodynamic coefficient:

[0015] ;

[0016] in, is the aerodynamic coefficient of the elastic model, is the aerodynamic coefficient of the rigid model;

[0017] S40. Perform aerodynamic coefficient correction.

[0018] Furthermore, the aerodynamic coefficient correction in S40 includes the following steps:

[0019] S41. If the rigid model is a rigid model based on a frame configuration, the static aeroelastic effect correction formula for the aerodynamic coefficients of the rigid model based on the frame configuration is as follows:

[0020] ;

[0021] in, is the aerodynamic coefficient of the rigid model based on the frame configuration after correction of the static aeroelastic effect, and A is the aerodynamic coefficient of the rigid model;

[0022] S42. If the rigid model is a cruise-configuration rigid model, the static aeroelastic effect correction formula for the aerodynamic coefficients of the cruise-configuration rigid model is as follows:

[0023] ;

[0024] in, is the aerodynamic coefficient of the rigid model based on the cruise configuration after correction of the static aeroelastic effect, is the difference in aerodynamic coefficients between the rigid model based on the frame configuration and the rigid model based on the cruise configuration under the same test conditions.

[0025] The static aeroelastic influence correction method for the full-machine model of a large aspect ratio aircraft of the present invention adopts the "incremental method" as the correction calculation method for different situations, whether the rigid model is a rigid model based on a frame configuration or a rigid model based on a cruise configuration; for the situation where the rigid model is a rigid model based on a frame configuration, the "static aeroelastic influence amount" is superimposed as a correction value on the rigid reference aerodynamic test data of the frame configuration for correction; for the situation where the rigid model is a rigid model based on a cruise configuration, the "static aeroelastic influence amount" and the "difference between different configurations" are both superimposed as correction values ​​on the rigid reference aerodynamic test data of the frame configuration for correction.

[0026] The static aeroelastic influence correction method for the full-aircraft model of a large aspect ratio aircraft of the present invention takes into account the influence of the elastic deformation of the aircraft structure, and performs static aeroelastic influence correction on the wind tunnel test data. The correction accuracy is higher than that of the static aeroelastic influence correction method based on engineering calculations or numerical simulations. The method is applicable not only to the prototype configuration, but also to the cruise configuration. The corrected test data is used for the flight control law design of the aircraft, meeting the demand for correction of the correlation between the aircraft's ground and earth data, saving test cycle and funds, and having practical engineering value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a flow chart of a method for correcting static aeroelastic effects of a full-machine model of a high-aspect-ratio aircraft. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0029] Example: Figure 1 As shown, the method for correcting the static aeroelastic effect of the full-aircraft model of a high-aspect-ratio aircraft of this embodiment includes the following steps:

[0030] S10. Create a rigid model and an elastic model;

[0031] S20. Conduct wind tunnel tests;

[0032] Conduct wind tunnel tests on rigid models to obtain the aerodynamic coefficients of the rigid models;

[0033] Conduct wind tunnel tests on elastic models to obtain aerodynamic coefficients of the elastic models;

[0034] S30. Obtaining static aeroelastic influence;

[0035] Under each flight state, the static aeroelastic influence ΔA under each flight state is obtained according to the static aeroelastic influence = elastic model aerodynamic coefficient - rigid model aerodynamic coefficient:

[0036] ;

[0037] in, is the aerodynamic coefficient of the elastic model, is the aerodynamic coefficient of the rigid model;

[0038] S40. Perform aerodynamic coefficient correction.

[0039] Furthermore, the aerodynamic coefficient correction in S40 includes the following steps:

[0040] S41. If the rigid model is a rigid model based on a frame configuration, the static aeroelastic effect correction formula for the aerodynamic coefficients of the rigid model based on the frame configuration is as follows:

[0041] ;

[0042] in, is the aerodynamic coefficient of the rigid model based on the frame configuration after correction of the static aeroelastic effect, and A is the aerodynamic coefficient of the rigid model;

[0043] S42. If the rigid model is a cruise-configuration rigid model, the static aeroelastic effect correction formula for the aerodynamic coefficients of the cruise-configuration rigid model is as follows:

[0044] ;

[0045] in, is the aerodynamic coefficient of the rigid model based on the cruise configuration after correction of the static aeroelastic effect, is the difference in aerodynamic coefficients between the rigid model based on the frame configuration and the rigid model based on the cruise configuration under the same test conditions.

[0046] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the description and implementation methods. For those familiar with the art, all features disclosed in the present invention, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for correcting the static aeroelastic effect of a full-body model of a high-aspect-ratio aircraft, characterized in that: The following steps are involved: S10. Create a rigid model and an elastic model; S20. Conduct wind tunnel tests; Conduct wind tunnel tests on rigid models to obtain the aerodynamic coefficients of the rigid models; Conduct wind tunnel tests on elastic models to obtain aerodynamic coefficients of the elastic models; S30. Obtaining static aeroelastic influence; Under each flight state, the static aeroelastic influence ΔA under each flight state is obtained according to the static aeroelastic influence = elastic model aerodynamic coefficient - rigid model aerodynamic coefficient: ； in, is the aerodynamic coefficient of the elastic model, is the aerodynamic coefficient of the rigid model; S40. Perform aerodynamic coefficient correction; The following steps are involved: S41. If the rigid model is a rigid model based on a frame configuration, the static aeroelastic effect correction formula for the aerodynamic coefficients of the rigid model based on the frame configuration is as follows: ； in, is the aerodynamic coefficient of the rigid model based on the frame configuration after correction of the static aeroelastic effect, and A is the aerodynamic coefficient of the rigid model; S42. If the rigid model is a cruise-configuration rigid model, the static aeroelastic effect correction formula for the aerodynamic coefficients of the cruise-configuration rigid model is as follows: ； in, is the aerodynamic coefficient of the rigid model based on the cruise configuration after correction of the static aeroelastic effect, is the difference in aerodynamic coefficients between the rigid model based on the frame configuration and the rigid model based on the cruise configuration under the same test conditions.

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