A design method for lateral and heading control surfaces with sideslip angle adaptation

Abstract

The present application discloses a method for designing a lateral and heading control rudder surface with adaptive sideslip angle. Firstly, the target parameters of the rolling moment coefficient and the yaw moment coefficient of the rudder surface are calculated by means of the wind resistance design index and the lateral and heading moment characteristic matrix. Subsequently, the root chord length parameters of the rudder surface are obtained by fitting the whole-machine digital models with different root chord lengths. Then, a root-tip ratio set is established, and a span set is obtained by simulating a number of whole-machine digital models with different spans. A number of whole-machine digital models are regenerated by means of the root-tip ratio set and the span set, and fitting calculations are performed thereon to obtain the length and tip chord length of the rudder surface. Finally, the rudder surface installation point is determined according to the root chord length, span and tip chord length. The present invention utilizes the principle of component coupling interference to ensure that the sideslip angle caused by the crosswind disturbance during the flight of the aircraft can be balanced only by the deflection of the aileron, thereby solving the problems of complex whole-machine components and system composition, heavy weight and high cost caused by the coordinated use of rudder and aileron dual rudders in conventional aircraft.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft design, and in particular to a method for designing a lateral heading control rudder surface with sideslip angle self-adaptation. Background Art

[0002] The sideslip angle is the angle between the incoming flow velocity and the wing symmetry plane. When the flight speed is on the right side of the aircraft's symmetry plane, it is defined as right side slip (positive sideslip), and when the flight speed is on the left side of the aircraft's symmetry plane, it is defined as left side slip (positive sideslip). The sideslip angle is caused by the lateral component of aerodynamic force; generally, an aircraft will encounter different degrees of crosswind during normal flight, resulting in a sideslip angle during flight;

[0003] In the prior art, in order to eliminate the sideslip angle, the rudder is generally deflected to balance the yaw moment and the aileron is deflected to balance the roll moment. That is, the rudder and the aileron need to be deflected at the same time to eliminate the sideslip angle. The above-mentioned method of eliminating the sideslip angle is to use a single-function rudder to balance the yaw moment and the roll moment caused by the sideslip angle respectively. Since the rudder has a single function, more rudders are used during the flight to eliminate the sideslip angle, which brings about a large aerodynamic drag and is not conducive to the cruise performance. At the same time, for this single-function rudder mode, different rudders need to be designed for different functions, and the design is relatively complex and requires more servos. Summary of the invention

[0004] The main purpose of the present application is to provide a method for designing a lateral and heading control rudder surface with adaptive sideslip angle, aiming to solve the defects of complex structure existing in the prior art.

[0005] This application achieves the above objectives through the following technical solutions:

[0006] A method for designing a lateral heading control rudder surface with sideslip angle self-adaptation comprises the following steps:

[0007] Calculate the target parameters of the rolling moment coefficient and the yaw moment coefficient of the rudder surface according to the wind resistance design index and the lateral moment characteristic matrix;

[0008] generating a plurality of full-aircraft digital models with different root chord lengths, and respectively importing a yaw moment coefficient target parameter and a deflection angle range into each of the full-aircraft digital models to calculate the root chord length of the rudder surface;

[0009] Establish root-shoot ratio set;

[0010] Generate a number of full-aircraft digital models with different spans according to the root-tip ratio set and the root chord length, import the rolling moment coefficient target parameter and the deflection angle range fitting calculation into each of the full-aircraft digital models, and obtain the span set;

[0011] Generate a number of full-aircraft digital models according to the span set and the root-to-tip ratio set, calculate the lift-to-drag ratio by fitting, and obtain a lift-to-drag ratio set;

[0012] Calculating the span and tip chord length of the control surface according to the lift-to-drag ratio set and the root chord length;

[0013] The rudder surface installation point is determined according to the root chord length, span length and tip chord length.

[0014] Optionally, obtaining a target parameter of a rudder surface rolling moment coefficient and a target parameter of a rudder surface yaw moment coefficient according to the wind resistance design index and the lateral moment characteristic matrix includes the following steps:

[0015] Construct the lateral and heading moment characteristic matrix under different sideslip angles;

[0016] Draw the lateral and yaw moment characteristic matrix and draw the rolling moment coefficient C l Curve of sideslip angle β and yaw moment coefficient C n Curve of variation with sideslip angle β;

[0017] Combined with the constraint conditions, the rolling moment coefficient C is fitted respectively l Curve of sideslip angle β and yaw moment coefficient C n Target slope of the curve with sideslip angle β;

[0018] Calculate the maximum sideslip angle to keep the control surface balanced according to the wind resistance design index of the aircraft;

[0019] Set redundancy, and calculate the rolling moment coefficient target parameter according to the redundancy, the maximum sideslip angle and the target slope and yaw moment coefficient target parameters

[0020] Optionally, the maximum sideslip angle meets Among them, V1 represents the crosswind wind speed, and V2 represents the aircraft flow speed.

[0021] Optionally, generating a plurality of full-aircraft digital models with different root chord lengths, and importing the target parameter of the yaw moment coefficient and the deflection angle range into each of the full-aircraft digital models to calculate the root chord length of the rudder surface, comprises the following steps:

[0022] Get the maximum deflection angle δ of the rudder surface max ;

[0023] Assign fixed values ​​to the root-tip length and the span of the rudder surface, and assign several values ​​to the root chord length;

[0024] Produce a number of full machine digital models according to the root tip length, the span length and the number of chord lengths;

[0025] Combined with the maximum deflection angle δmax Simulating each of the full-machine digital models to obtain a number of yaw moments;

[0026] Establishing a relationship curve between the yaw moment coefficient and the root chord length according to each of the yaw moment coefficient target parameters and each of the root chord lengths, and calculating a calculation slope of the relationship curve;

[0027] The root chord length is calculated according to the calculated slope and the yaw moment coefficient target parameter.

[0028] Optionally, the root chord length satisfies where k cnr represents the calculated slope, Represents the yaw moment coefficient target parameter.

[0029] Optionally, establishing a root-shoot ratio set includes the following steps:

[0030] Set the root-shoot ratio variation range;

[0031] Set the single value increment of the root-shoot ratio;

[0032] Combined with the single value increment of the root-shoot ratio, each root-shoot ratio is determined within the root-shoot ratio variation range according to the relationship of an arithmetic progression, and a root-shoot ratio set is established.

[0033] Optionally, a plurality of full-machine digital models with different spans are generated according to the root-tip ratio set and the root chord length, and a rolling moment coefficient target parameter and a deflection angle range fitting calculation are introduced into each of the full-machine digital models to obtain a span set;

[0034] Select a tip ratio as the current root-tip ratio, call up the root chord length, and assign a certain span length;

[0035] Generate a number of full-machine digital models according to the current root-tip ratio, root chord length and a number of spans;

[0036] Get the maximum deflection angle δ of the rudder surface max , respectively import the rolling moment coefficient target parameters and the maximum deflection angle δ into each of the full-machine digital models max Solve the flow field and obtain the rolling moment coefficient under different spans

[0037] Establishing a curve relationship between the rolling moment coefficient and the rudder surface length according to the rolling moment coefficient under different lengths, and calculating the slope of the curve relationship;

[0038] According to the formula Calculating a current extension corresponding to the current root-to-tip ratio;

[0039] Repeat the steps to select a tip ratio as the current root-tip ratio, call the root chord length, and assign several spans until the current spans of all current root-tip ratios are obtained and a span set is established.

[0040] Optionally, generating a plurality of full-aircraft digital models according to the span set and the root-to-tip ratio set, fitting and calculating the lift-to-drag ratio, and obtaining the lift-to-drag ratio set comprises the following steps:

[0041] A set of corresponding root-shoot ratios and extension lengths are retrieved to generate a digital model of the whole machine;

[0042] Importing a deflection angle parameter into the full-machine digital model to perform a process solution on the full-machine digital model to obtain a lift-to-drag ratio corresponding to the root-to-tip ratio;

[0043] Repeat the steps of calling a set of corresponding root-to-tip ratios and span lengths to generate a full-aircraft digital model until all lift-to-drag ratios are obtained;

[0044] All lift-to-drag ratios are grouped into the same set to obtain a lift-to-drag ratio set.

[0045] Optionally, calculating the span and tip chord length of the control surface according to the lift-to-drag ratio set and the root chord length comprises the following steps:

[0046] Retrieving the lift-to-drag ratio set to obtain a maximum lift-to-drag ratio;

[0047] According to the maximum lift-to-drag ratio, extract the corresponding root-to-tip ratio from the root-to-tip ratio set as the maximum root-to-tip ratio;

[0048] Calculating the span according to the maximum lift-to-drag ratio and the rolling moment coefficient target parameter;

[0049] The tip chord length is calculated according to the maximum root-to-tip ratio and the root chord length.

[0050] Optionally, an isolation gap is provided between the control surface and the fuselage, and the width of the isolation gap is not greater than 3 mm.

[0051] Compared with the prior art, this application has the following beneficial effects:

[0052] The present application first calculates the target parameters of the rolling moment coefficient and the yaw moment coefficient of the rudder through the wind-resistant design index and the lateral and directional moment characteristic matrix, and then obtains the root chord length parameters of the rudder by fitting the full-aircraft digital models with different root chord lengths; then establishes a root-tip ratio set, obtains the span set through the simulation of several full-aircraft digital models with different spans, regenerates several full-aircraft digital models through the root-tip ratio set and the span set, and performs fitting calculations here to obtain the length and tip chord length of the rudder, and finally determines the rudder installation point according to the root chord length, span and tip chord length.

[0053] Compared with the prior art, the multifunctional control surface described in the present invention fits closely with the fuselage. When the turning angle of the multifunctional control surface changes, the airflow passing through the multifunctional control surface will produce coupling interference with the fuselage, thereby balancing the sideslip angle caused by the side wind disturbance. That is, the present application balances the sideslip angle caused by the side wind disturbance during the flight of the aircraft only by aileron deflection, and solves the problem of complex composition, heavy weight and high cost of the entire aircraft components and system caused by the coordinated use of rudder and aileron dual rudders in conventional aircraft. This has important reference value for weight control and low-cost design of small aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A flow chart of a method for designing a sideslip angle adaptive lateral heading control surface provided in Embodiment 1 of the present application;

[0055] Figure 2 It is the lateral heading characteristic matrix of the example in implementation mode 1 of the present application;

[0056] Figure 3 It is a characteristic curve diagram of the example in implementation mode 1 of the present application;

[0057] Figure 4 This is the control principle diagram of the lateral heading control rudder;

[0058] The purpose, features and advantages of this application will be further described in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0059] 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.

[0060] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0061] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0063] Implementation Method 1

[0064] This embodiment, as an optional embodiment of the present application, discloses a method for designing a lateral heading control rudder surface with sideslip angle adaptation, comprising the following steps:

[0065] It should be noted that this application will also explain in detail each step of this implementation through specific examples;

[0066] S1. Calculate the rolling moment coefficient target parameters and yaw moment coefficient target parameters of the rudder surface according to the wind resistance design index and the lateral and directional moment characteristic matrix;

[0067] S11, constructing the lateral heading moment characteristic matrix under different sideslip angles;

[0068] The aircraft's sideslip angle β parameter is set, and the lateral and yaw moment characteristic matrix corresponding to different sideslip angles is constructed by numerical simulation technology;

[0069] Its expression is:

[0070] In the specific example, for the conventional UAV target, numerical simulation is used to calculate the yaw moment coefficient and roll moment coefficient of the whole aircraft at different sideslip angles when the Mach number is 0.2 and the angle of attack is 10° (landing and level flight state), and the resulting lateral heading characteristic matrix is ​​as follows: Figure 2 As shown;

[0071] S12, draw the lateral and heading moment characteristic matrix and draw the rolling moment coefficient C l Curve of sideslip angle β and yaw moment coefficient C n Curve of variation with sideslip angle β;

[0072] According to the lateral and yaw moment characteristic matrix in step S11, the lateral and yaw moment characteristic matrix is ​​respectively plotted to plot the rolling moment coefficient C l Curve of sideslip angle β and yaw moment coefficient C n Curve of variation with sideslip angle β;

[0073] In a specific example, the above two curves are as follows Figure 3 As shown;

[0074] S13, combining the constraint conditions, respectively fitting the rolling moment coefficient C l Curve of sideslip angle β and yaw moment coefficient C n Target slope of the curve with sideslip angle β;

[0075] Call the constraint formula of the target slope k1<0, k2>0, k1*k2<0;

[0076] Combined with the above constraint formula, the rolling moment coefficient C is fitted l As the sideslip angle β changes, the target slope k1 of the curve is obtained, and the yaw moment coefficient C is fitted. n With the change curve of the sideslip angle β, the target slope k2 of the change curve is obtained;

[0077] In the specific example, it can be calculated that k1 = -0.0017, k2 = 0.00086;

[0078] By introducing the target slopes k1 and k2, the rolling moment coefficient target parameters and the yaw moment coefficient target parameters are associated with the aircraft's body characteristics, and then the various parameters of the multifunctional control surface are associated with the aircraft's body characteristics through the rolling moment coefficient target parameters and the yaw moment coefficient target parameters, thereby ensuring that the multifunctional control surface can achieve adaptive adjustment according to the sideslip angle;

[0079] S14. Calculate the maximum sideslip angle for maintaining control surface balance based on the wind resistance design index of the aircraft;

[0080] Obtaining the wind resistance design index of the aircraft, wherein the wind resistance design index includes the crosswind speed V1 and the aircraft incoming flow speed V2;

[0081] According to the formula The maximum sideslip angle β of the control surface balance can be calculated max ;

[0082] In a specific example, the aircraft is required to have a crosswind resistance of 10m / s, and the aircraft flow speed is 60m / s. According to the formula, the maximum sideslip angle that the control surface design needs to balance is β max =9.5°;

[0083] S15, setting redundancy, and calculating a target parameter of a rolling moment coefficient according to the redundancy, the maximum sideslip angle and the target slope. and yaw moment coefficient target parameters

[0084] First, calculate according to the formula and Calculate the maximum sideslip angle β to maintain the balance of the control surface max The rolling moment coefficient to be generated and the yaw moment coefficient Wherein k1 and k2 are two target slopes in step S13 respectively;

[0085] Then, according to the security level requirements, technicians in the field can freely set the redundancy, and then use the formula and Calculate the rolling moment coefficient target parameters separately and yaw moment coefficient target parameters Where c represents redundancy;

[0086] In a specific example, the rolling moment coefficient and the yaw moment coefficient can be calculated by combining relevant parameters:

[0087] Considering a 10% design margin for the rudder, that is, a design safety factor of c = 0.9, the design target of the rudder capacity is calculated according to the formula:

[0088] S2, generating a plurality of full-aircraft digital models with different root chord lengths, and respectively importing a yaw moment coefficient target parameter and a deflection angle range into each of the full-aircraft digital models to calculate the root chord length of the control surface;

[0089] S21. Obtain the maximum deflection angle δ of the control surface max ;

[0090] First, the deflection angle range of the rudder surface is calculated according to the travel limit of the servo [-δ max ,δ max]; define the left rudder surface upward and the right rudder surface downward as positive, that is, the multi-function rudder surface deflection δ max When the angle is δ, the left rudder surface is deflected max Angle, right rudder downward deflection δ max angle;

[0091] In a specific implementation, the rudder surface deflection angle range [-25°, 25°] is calculated according to the travel of the servo, that is, δ max =25°;

[0092] S22, assigning fixed values ​​to the root tip length and the span length of the rudder surface, and assigning a number of values ​​to the root chord length;

[0093] Assign fixed values ​​to the root tip length and the span length of the rudder surface, such as 1000mm, and assign several values ​​to the root chord length, such as l1=300mm, l2=300mm, l3=300mm, etc., where the optimal number of preset root chord length values ​​is 3-4 to reduce the amount of calculation;

[0094] In a specific implementation, the tip chord length l of the rudder surface is set t , rudder surface length l s =800mm, the rudder surface has a fixed deflection angle of 25°, and three different root chord lengths are given: l1=100mm, l2=200mm, l3=300mm;

[0095] S23, producing a plurality of full machine digital models according to the root tip length, the spread length and the plurality of chord lengths;

[0096] In a specific implementation, the root chord length is divided into three groups, the tip chord length and the span length of each group are the same, and the root chord length cannot take the three different values ​​in S22;

[0097] Generate three full-machine digital models respectively using the above three sets of parameters;

[0098] S24, combined with the maximum deflection angle δ max Simulating each of the full-machine digital models to obtain a number of yaw moments;

[0099] The maximum deflection angle δ obtained in step S21 max Substitute them into the full-machine digital models in step S23 respectively, and calculate the multifunctional rudder deflection δ under different root chord lengths through numerical simulation max The yaw moment coefficient C generated by the whole aircraft at angle n r1 , C n r2 , C n r3 ,...C nri ;

[0100] In the specific implementation, since there are only three full-machine digital models, three yaw moment values ​​are generated;

[0101] S25, establishing a relationship curve between the yaw moment coefficient and the root chord length according to each of the yaw moment coefficient target parameters and each of the root chord lengths, and calculating a calculation slope of the relationship curve;

[0102] Combined with the yaw moment coefficient C obtained in step S24 n r1 , C n r2 , C n r3 ,...C nri , by numerical simulation, a relationship curve between the yaw moment coefficient and the root chord length is established under different rudder root chord lengths, a variation curve of the yaw moment coefficient with the rudder root chord length is drawn, and the slope of the variation curve is calculated at the same time, and the above slope is the calculated slope;

[0103] In a specific embodiment, the slope k is calculated Cn r =-1.94524×10 -5 ;

[0104] S26. Calculate the root chord length according to the calculated slope and the yaw moment coefficient target parameter.

[0105] Call the yaw moment coefficient target parameter calculated in step S15 Calculate the root chord length of the aircraft, where the root chord length satisfies where k cnr represents the calculated slope, represents the target parameter of the yaw moment coefficient;

[0106] In a specific implementation, the root chord length of the rudder surface is calculated according to the formula: r =420mm;

[0107] S3, establishing a root-shoot ratio set;

[0108] S31, setting the root-shoot ratio variation range;

[0109] Set the root-shoot ratio range [m,n] as needed;

[0110] S32, setting a single value increment of the root-shoot ratio;

[0111] Set the single value increment Δλ of the root-shoot ratio as needed;

[0112] S33, combining the single value increment of the root-shoot ratio, determining each root-shoot ratio within the root-shoot ratio variation range according to the relationship of an arithmetic progression, and establishing a root-shoot ratio set;

[0113] Since the values ​​are taken within the range of the root-shoot ratio according to the arithmetic progression, the number of root-shoot ratios satisfies According to the above relationship, all root-shoot ratios can be calculated and a root-shoot ratio set can be established; its expression is {λ1, λ2, ..., λ i}, where i represents the number of the root-shoot ratio;

[0114] In a specific implementation, the range of the rudder tip-root ratio is set to [0.4, 0.5], the tip-root single-step cycle variable is set to Δλ=0.001, and the calculation cycle number s=101;

[0115] S4, generating a plurality of full-machine digital models with different spans according to the root-tip ratio set and the root chord length, importing the rolling moment coefficient target parameter and the deflection angle range fitting calculation into each of the full-machine digital models, and obtaining a span set;

[0116] S41, selecting a tip ratio as the current root-tip ratio, calling the root chord length, and assigning a certain span length;

[0117] The root-to-shoot ratio set {λ1, λ2, ..., λ i}, select any root-to-shoot ratio, such as λ1; use λ1 as the current root-to-shoot ratio;

[0118] The root chord length calculated in step S26 is called, and several extension parameters are set at the same time. It is recommended to set about 3 extensions;

[0119] S42, generating a plurality of full-machine digital models according to the current root-tip ratio, root chord length and a plurality of span lengths;

[0120] The grouping is performed according to the method of step S23, and the corresponding full-machine digital models are generated. Since there are three extension lengths, three full-machine digital models will be generated in this step;

[0121] S43, obtaining the maximum deflection angle δ of the control surface max , respectively import the rolling moment coefficient target parameters and the maximum deflection angle δ into each of the full-machine digital models max Solve the flow field and obtain the rolling moment coefficient under different spans

[0122] Call the maximum deflection angle δ obtained in step S21 max , and at the same time, calling the rolling moment coefficient target parameter obtained in step S15, merging the above two parameters into a data group, and importing the above data groups into each of the full-machine digital models in step S42;

[0123] Perform CFD flow field solution to obtain the rolling moment coefficient of the whole aircraft under different rudder spans

[0124] S44, establishing a curve relationship between the rolling moment coefficient and the rudder surface length according to each rolling moment coefficient, and calculating the slope of the curve relationship;

[0125] Call the extension parameter set in step S41 and the rolling moment coefficient obtained in step S43 Fitting and establishing the rolling moment coefficients and the relationship between the rolling moment coefficients and the rudder surface extension curve;

[0126] Calculate the slope of the above curve relationship;

[0127] S45, according to the formula Calculate the current extension corresponding to the current root-tip ratio, where represents the slope calculated in step S44, represents the target parameter of the rolling moment coefficient;

[0128] S46, repeat the steps to select a tip ratio as the current root-tip ratio, call the root chord length, and assign a number of spans until the current spans of all current root-tip ratios are obtained, and a span set is established;

[0129] In steps S41-S45, the length corresponding to the root-tip ratio λ1 is calculated. Call the root-shoot ratio λ2 again and repeat steps S41-S45 to calculate the lengths of all root-shoot ratios. Group the above length values ​​into the same set to obtain the length set Where i represents the root-shoot ratio parameter, and the same number is used here to represent the corresponding relationship between the extension and the root-shoot ratio;

[0130] S5, generating a plurality of full-aircraft digital models according to the span set and the root-to-tip ratio set, and fitting and calculating the lift-to-drag ratio to obtain a lift-to-drag ratio set;

[0131] S51, calling a set of corresponding root-to-shoot ratios and extension lengths to generate a full-machine digital model;

[0132] According to the same principle as number i, corresponding parameters are respectively retrieved in the length set and the root-shoot ratio set, such as length l s 1 and the root-tip ratio λ1, combined with the root chord length obtained in step S26 to regenerate a full machine digital model;

[0133] S52, importing a deflection angle parameter into the full-machine digital model to perform a process solution on the full-machine digital model to obtain a lift-to-drag ratio corresponding to the root-to-tip ratio;

[0134] Retrieve the maximum deflection angle δ obtained in step S21 max , import it into the full-machine digital model generated in step S51, perform process solving, and calculate the corresponding lift-to-drag ratio a1;

[0135] S53, repeating the step of retrieving a set of mutually corresponding root-to-tip ratios and span lengths to generate a full-aircraft digital model, until all lift-to-drag ratios are obtained;

[0136] Call another set of span and root-to-tip ratios with the same number i, repeat steps S51 and S52, and calculate the corresponding lift-to-drag ratios until all lift-to-drag ratios are obtained;

[0137] S54, grouping all lift-to-drag ratios into the same set to obtain a lift-to-drag ratio set;

[0138] In a specific implementation, since there are 101 root-to-tip ratios, the obtained lift-to-drag ratio set will contain 101 parameters;

[0139] S6. Calculating the span and tip chord length of the control surface according to the lift-to-drag ratio set and the root chord length;

[0140] S61, retrieving the lift-to-drag ratio set to obtain a maximum lift-to-drag ratio;

[0141] Retrieving the lift-to-drag ratio set obtained in step S54, and retrieving the maximum lift-to-drag ratio in the lift-to-drag ratio set;

[0142] S62, extracting the corresponding root-to-tip ratio from the root-to-tip ratio set according to the maximum lift-to-drag ratio as the maximum root-to-tip ratio;

[0143] Based on the principle of same numbering, extracting the corresponding root-to-tip ratio from the root-to-tip ratio according to the maximum lift-to-drag ratio as the maximum root-to-tip ratio;

[0144] S63, calculating the span according to the maximum lift-to-drag ratio and the rolling moment coefficient target parameter;

[0145] Based on the maximum lift-to-drag ratio, combined with the rolling moment coefficient target parameters and formula Calculate the span of the aircraft;

[0146] S64, calculating the tip chord length according to the maximum root-tip ratio and the root chord length;

[0147] According to the definition of root-shoot ratio Combined with the root chord length, the tip chord length is calculated, that is, the tip chord length satisfies l t =λ ikmax *l r .

[0148] In the specific example, the maximum lift-to-drag ratio of the whole machine is k max =0.574, calculate the rudder tip-root ratio λ ikmax =0.446; therefore, the rudder surface length l s =840mm, calculate the rudder tip chord length l according to the definition of rudder tip-root ratio t =λ ikmax *l r =187.32mm;

[0149] S7, determining the rudder surface installation point according to the root chord length, span length and tip chord length;

[0150] The multifunctional rudder surface installation point is located on the wing, and the rudder surface installation point is determined according to the root chord length, the span length and the tip chord length. The installation point needs to ensure that after the multifunctional rudder surface is installed, the end of the multifunctional rudder surface facing the fuselage is in contact with the fuselage;

[0151] In order to avoid interference between the fuselage and the multifunctional control surface, and also to avoid wear between the fuselage and the control surface, an isolation gap is provided between the control surface and the fuselage, and the width of the isolation gap is not greater than 3 mm.

[0152] Reference Figure 4 , which discloses the working principle of the lateral heading rudder described in the present application: the left and right rudder surfaces are differentially deflected (as shown in the figure, the left aileron is deflected downward and the right aileron is deflected upward), so that the left and right wings produce a certain lift difference, thereby generating a lateral control moment coefficient, that is, a rolling moment coefficient (as shown in the figure F2); at the same time, the left and right rudder surfaces are differentially deflected while generating coupling interference to the fuselage on both sides, so that a certain pressure difference is generated on both sides of the fuselage, thereby generating a heading control moment coefficient, that is, a yaw moment coefficient (as shown in the figure F1); therefore, the design of the rudder surface of the present invention can automatically balance the sideslip angle caused by the side wind disturbance.

[0153] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for designing a lateral heading control surface with sideslip angle adaptation, characterized in that: The following steps are involved: Construct the lateral and heading moment characteristic matrix under different sideslip angles; Draw the lateral and yaw moment characteristic matrix and draw the rolling moment coefficient C l Curve of sideslip angle β and yaw moment coefficient C n Curve of variation with sideslip angle β; Combined with the constraint conditions, the rolling moment coefficient C is fitted respectively l Curve of sideslip angle β and yaw moment coefficient C n Target slope of the curve with sideslip angle β; The maximum sideslip angle to maintain the balance of the control surface is calculated according to the wind resistance design index of the aircraft, and the maximum sideslip angle satisfies Where V1 represents the crosswind speed, and V2 represents the aircraft flow speed; Set redundancy, and calculate the rolling moment coefficient target parameter according to the redundancy, the maximum sideslip angle and the target slope and yaw moment coefficient target parameters generating a plurality of full-aircraft digital models with different root chord lengths, and respectively importing a yaw moment coefficient target parameter and a deflection angle range into each of the full-aircraft digital models to calculate the root chord length of the rudder surface; Establish root-shoot ratio set; Generate a number of full-aircraft digital models with different spans according to the root-tip ratio set and the root chord length, import the rolling moment coefficient target parameter and the deflection angle range fitting calculation into each of the full-aircraft digital models, and obtain the span set; Generate a number of full-aircraft digital models according to the span set and the root-to-tip ratio set, calculate the lift-to-drag ratio by fitting, and obtain a lift-to-drag ratio set; Calculating the span and tip chord length of the control surface according to the lift-to-drag ratio set and the root chord length; The installation point of the rudder surface is determined according to the root chord length, the span length and the tip chord length, wherein one end of the rudder surface is in contact with the fuselage.

2. The control surface design method according to claim 1, characterized in that: The method of generating a plurality of full-aircraft digital models with different root chord lengths and importing the target parameter of the yaw moment coefficient and the deflection angle range into each of the full-aircraft digital models to calculate the root chord length of the rudder surface comprises the following steps: Get the maximum deflection angle δ of the rudder surface max ; Assign fixed values ​​to the root-tip length and the span of the rudder surface, and assign several values ​​to the root chord length; Produce a number of full machine digital models according to the root tip length, the span length and the number of chord lengths; Combined with the maximum deflection angle δ max Simulating each of the full-machine digital models to obtain a number of yaw moments; Establishing a relationship curve between the yaw moment coefficient and the root chord length according to each of the yaw moment coefficient target parameters and each of the root chord lengths, and calculating a calculation slope of the relationship curve; The root chord length is calculated according to the calculated slope and the yaw moment coefficient target parameter.

3. The control surface design method according to claim 2, characterized in that: The root chord length satisfies where k cnr represents the calculated slope, Represents the yaw moment coefficient target parameter.

4. The control surface design method according to claim 1, characterized in that: Described establishing root-shoot ratio set comprises the following steps: Set the root-shoot ratio variation range; Set the single value increment of the root-shoot ratio; Combined with the single value increment of the root-shoot ratio, each root-shoot ratio is determined within the root-shoot ratio variation range according to the relationship of an arithmetic progression, and a root-shoot ratio set is established.

5. The control surface design method according to claim 1, characterized in that: generating a plurality of full-machine digital models with different spans according to the root-tip ratio set and the root chord length, importing the rolling moment coefficient target parameter and the deflection angle range fitting calculation into each of the full-machine digital models, and obtaining the span set; Select a tip ratio as the current root-tip ratio, call up the root chord length, and assign a certain span length; Generate a number of full-machine digital models according to the current root-tip ratio, root chord length and a number of spans; Get the maximum deflection angle δ of the rudder surface max , respectively import the rolling moment coefficient target parameters and the maximum deflection angle δ into each of the full-machine digital models max Solve the flow field and obtain the rolling moment coefficient under different spans; Establishing a curve relationship between the rolling moment coefficient and the rudder surface length according to the rolling moment coefficient under different lengths, and calculating the slope of the curve relationship; According to the formula Calculating a current extension corresponding to the current root-to-tip ratio; Repeat the steps to select a tip ratio as the current root-tip ratio, call the root chord length, and assign several spans until the current spans of all current root-tip ratios are obtained and a span set is established.

6. The control surface design method according to claim 1, characterized in that: The step of generating a plurality of full-aircraft digital models according to the span set and the root-to-tip ratio set, fitting and calculating the lift-to-drag ratio, and obtaining the lift-to-drag ratio set comprises the following steps: A set of corresponding root-shoot ratios and extension lengths are retrieved to generate a digital model of the whole machine; Importing a deflection angle parameter into the full-machine digital model to perform a process solution on the full-machine digital model to obtain a lift-to-drag ratio with the root-to-tip ratio parameter; Repeat the steps of calling a set of corresponding root-to-tip ratios and span lengths to generate a full-aircraft digital model until all lift-to-drag ratios are obtained; All lift-to-drag ratios are grouped into the same set to obtain a lift-to-drag ratio set.

7. The method for designing a rudder surface according to claim 6, characterized in that: The step of calculating the span and tip chord length of the control surface according to the lift-to-drag ratio set and the root chord length comprises the following steps: Retrieving the lift-to-drag ratio set to obtain a maximum lift-to-drag ratio; According to the maximum lift-to-drag ratio, extract the corresponding root-to-tip ratio from the root-to-tip ratio set as the maximum root-to-tip ratio; Calculating the span according to the maximum lift-to-drag ratio and the rolling moment coefficient target parameter; The tip chord length is calculated according to the maximum root-to-tip ratio and the root chord length.

8. The control surface design method according to claim 1, characterized in that: An isolation gap is provided between the control surface and the fuselage, and the width of the isolation gap is not greater than 3 mm.

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