Method for determining the maximum hinge moment of rudder of transport aircraft

Abstract

The present application provides a method for determining the maximum hinge moment of a rudder of a transport aircraft, comprising the following steps: determining a rudder hinge moment calculation formula of a transport aircraft; determining an aircraft speed when the maximum hinge moment of the rudder occurs, and, on the basis of the aircraft speed, determining calculation parameters corresponding to the maximum hinge moment of the rudder, the calculation parameters comprising a rudder deflection, and the angle of attack and angle of sideslip of an aircraft; and, on the basis of the calculation parameters corresponding to the maximum hinge moment of the rudder and the rudder hinge moment calculation formula, obtaining the maximum hinge moment of the rudder. Compared with previous empirical methods, the method provided by the present application has theoretical supports, can quickly calculate the maximum hinge moment of the rudder without performing full-envelope full-configuration hinge moment calculation, is suitable for determining the maximum hinge moment of rudders during an aircraft schematic design phase, involves concise and rapid calculation, and achieves higher result accuracy.

Description

A method for determining the maximum hinge torque of the rudder of a transport aircraft Technical Field

[0001] The present application relates to the field of aircraft operation control, and in particular to a method for determining the maximum hinge torque of a rudder of a transport aircraft. Background Art

[0002] The maximum hinge torque is an important design input for aircraft flight control systems. The maximum hinge torque of each control surface has a significant impact on the design of each control surface actuator. It not only determines the weight and size of the actuator, but also affects the layout of the actuator in the aircraft. Therefore, determining the maximum hinge torque is a crucial task in aircraft design.

[0003] Typically, determining the maximum rudder hinge moment requires combining aerodynamic numerical calculations or hinge moment coefficients obtained from wind tunnel testing. This involves extensive calculations of hinge moments for various configurations throughout the aircraft's flight envelope, including steady sideslip, engine failure, crosswind resistance, and coordinated turns. A maximum rudder hinge moment value is then selected based on the calculated results. This traditional calculation method is complex, requiring design inputs for control surface limit curves and the flight envelope, as well as complete data on the hinge moment coefficients. During the aircraft concept design phase, control surface limit curves have yet to be developed, and wind tunnel testing for hinge moment has yet to be conducted. Consequently, a comprehensive and detailed knowledge of the hinge moment coefficients is lacking. Therefore, it is crucial to quickly and accurately determine the maximum hinge moment during the aircraft concept design phase.

[0004] Summary of the Invention

[0005] The purpose of the present application is to provide a method for determining the maximum hinge torque of a transport aircraft rudder, so as to solve or alleviate at least one problem in the background technology.

[0006] The technical solution of the present application is: a method for determining the maximum hinge torque of a transport aircraft rudder, the method comprising the following steps:

[0007] Determine a formula for calculating the rudder hinge torque for the transport aircraft;

[0008] determining an aircraft speed at which a maximum rudder hinge moment occurs, and determining calculation parameters corresponding to the maximum rudder hinge moment based on the aircraft speed, the calculation parameters including rudder deflection, aircraft angle of attack, and sideslip angle;

[0009] The maximum rudder hinge moment is obtained according to the calculation parameters corresponding to the maximum rudder hinge moment and the rudder hinge moment calculation formula.

[0010] In a preferred embodiment of the present application, the rudder hinge torque calculation formula is:

[0011] Mh =C h (α, β, δ r )qS δ b δ

[0012] Where: M h is the rudder hinge moment;

[0013] C h is the rudder hinge moment coefficient, which is the aircraft angle of attack α, sideslip angle β, and rudder deflection δ r function;

[0014] q is the speed pressure;

[0015] S δ 、b δ are the rudder reference area and reference length (mean chord length) respectively.

[0016] In the preferred embodiment of this application, the approach speed of the aircraft with the maximum flight weight is selected as 1.23v s The aircraft speed corresponding to the maximum hinge moment.

[0017] In a preferred embodiment of the present application, the limit deflection is selected as the rudder deflection corresponding to the maximum hinge moment.

[0018] In a preferred embodiment of the present application, the aircraft approach trim angle of attack is selected as the aircraft angle of attack corresponding to the maximum hinge moment.

[0019] In a preferred embodiment of the present application, the aircraft approach trim angle of attack is selected to be 3 degrees.

[0020] In a preferred embodiment of the present application, 0 degrees is selected as the sideslip angle corresponding to the maximum hinge moment.

[0021] Compared with previous empirical methods, the method for determining the maximum hinge torque of the rudder of transport aircraft provided in this application has theoretical support. It can quickly calculate the maximum hinge torque of the rudder without performing full-envelope and full-configuration hinge torque calculations. It is suitable for determining the maximum hinge torque of the rudder during the aircraft design stage. The calculation is simple and fast, and the results are highly accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0023] FIG1 is a flow chart of a method for determining the maximum hinge torque of a transport aircraft rudder according to the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0025] In order to overcome the problem that the maximum hinge torque of the rudder cannot be obtained quickly and accurately due to the lack of many input conditions in the aircraft planning stage, this application proposes a method for quickly determining the maximum hinge torque of the rudder of transport aircraft, which realizes the rapid solution of the maximum hinge torque of the rudder without performing full-envelope and full-configuration hinge torque calculations.

[0026] As shown in FIG1 , the method for quickly determining the maximum hinge torque of the rudder of a transport aircraft provided in this application includes the following steps:

[0027] Step 1: Determine the calculation formula for the rudder hinge torque of the transport aircraft. The calculation formula for the rudder hinge torque is:

[0028] M h =C h (α, β, δ r )qS δ b δ

[0029] Where: M h is the rudder hinge moment;

[0030] C h is the rudder hinge moment coefficient, which is the aircraft angle of attack α, sideslip angle β, and rudder deflection δ r function;

[0031] q is the speed pressure;

[0032] S δ 、b δ are the rudder reference area and reference length (mean chord length) respectively.

[0033] Step 2: Determine the aircraft speed when the maximum rudder hinge moment occurs, and determine the calculation parameters corresponding to the maximum rudder hinge moment based on the aircraft speed. The calculation parameters include rudder deflection, aircraft angle of attack, and sideslip angle.

[0034] According to the hinge moment test results, the rudder hinge moment coefficient C h It increases with the increase of rudder deflection. When the rudder is deflected to the maximum angle and the sideslip angle is established, the rudder hinge torque decreases.

[0035] According to the results of rudder hinge torque during steady sideslip, engine failure, crosswind resistance, and coordinated turning, the maximum hinge torque occurs during the landing process with a strong crosswind. If the aircraft lands by the cross method, in the final stage, the rudder needs to be quickly manipulated to the maximum deflection to make the aircraft nose deflect in time to align with the runway, which can ensure the safety of the aircraft. Therefore, the approach speed corresponding to the maximum flight weight of the aircraft is selected as 1.23v in this application. s The aircraft speed corresponding to the maximum hinge moment. At this speed, the rudder is usually not yet deflected, so the rudder deflection is selected as the extreme deflection. The angle of attack is selected as the aircraft approach trim angle of attack. Based on model experience, an angle of attack of 3° is selected as the optimal calculated angle of attack in this application. Taking into account the crosswind direction and the direction of the rudder, the hinge moment is maximum when the sideslip angle is 0 degrees. Therefore, the sideslip angle is selected as zero degrees in this application, and the aircraft configuration is the landing configuration.

[0036] Step 3: Obtain the maximum rudder hinge moment according to the calculation parameters corresponding to the rudder deflection when the rudder deflection is the limit deflection (maximum hinge moment) and the rudder hinge moment calculation formula.

[0037] According to the rudder hinge torque calculation formula M h =C h (α, β, δ r )qS δ b δ , and the approach speed corresponding to the maximum hinge torque determined in step 2 is 1.23v s , approach trim angle of attack 3°, rudder maximum deflection, sideslip angle 0°, the aircraft configuration is landing configuration, calculate the rudder hinge torque, which is the maximum rudder hinge torque.

[0038] For example, in this embodiment of the present application, a transport aircraft needs to quickly calculate the maximum hinge torque of the rudder during the design phase. Using the method proposed in this application, the known calculation parameters are as follows:

[0039] The aircraft has a maximum flight weight of 30,000 kg. The approach speed corresponding to the maximum flight weight, 230 km / h, is selected as the speed state corresponding to the maximum rudder hinge moment. When calculating the maximum hinge moment, the angle of attack is set to the aircraft's approach trim angle of attack, i.e., 3°. The rudder deflection is set to the maximum rudder deflection of 25°, and the sideslip angle is set to 0°.

[0040] According to formula M h =C h (α, β, δ r )qS δ b δIn the above process, the approach speed is 230km / h, the approach trim angle of attack is 3°, the rudder limit deflection is 25°, the sideslip angle is 0°, and the aircraft configuration is the landing configuration. The corresponding hinge moment coefficient can be calculated as 0.35. The rudder reference area S of the aircraft δ The reference length of the rudder (mean chord length) is 3.9m2. δ is 1.2m2, and the maximum hinge torque of the rudder is finally calculated to be 4095N·m.

[0041] Compared with previous empirical methods, the method for quickly determining the maximum hinge torque of the rudder of transport aircraft provided in this application has theoretical support. It can quickly calculate the maximum hinge torque of the rudder without performing full-envelope and full-configuration hinge torque calculations. It is suitable for determining the maximum hinge torque of the rudder during the aircraft design stage. The calculation is simple and fast, and the results are highly accurate.

[0042] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for determining the maximum hinge moment of a rudder of a transport aircraft, characterized in that: The method comprises the following steps: Determine a calculation formula for the rudder hinge torque of the transport aircraft; Determine the aircraft speed when the maximum hinge moment of the rudder occurs, and determine the calculation parameters corresponding to the maximum hinge moment of the rudder according to the aircraft speed, wherein the calculation parameters include rudder deflection, aircraft angle of attack and sideslip angle; The maximum rudder hinge moment is obtained according to the calculation parameters corresponding to the maximum rudder hinge moment and the rudder hinge moment calculation formula.

2. The method for determining the maximum hinge moment of the rudder of a transport aircraft according to claim 1, characterized in that: The calculation formula of the rudder hinge moment is: h =C h (α, β, δ r )qS δ b δ Where: M h is the rudder hinge moment; C h is the rudder hinge moment coefficient, which is the aircraft angle of attack α, sideslip angle β, rudder deflection δ r Function of q is the speed pressure; S δ , b δ are the reference area and reference length of the rudder respectively.

3. The method for determining the maximum hinge moment of the rudder of a transport aircraft according to claim 1, characterized in that: Select the approach speed of the aircraft's maximum flight weight, 1.23v s Aircraft speed corresponding to the maximum hinge moment.

4. The method for determining the maximum hinge moment of the rudder of a transport aircraft according to claim 1, characterized in that: The limit deflection is selected as the rudder deflection state corresponding to the maximum hinge moment.

5. The method for determining the maximum hinge moment of the rudder of a transport aircraft according to claim 1, characterized in that: The aircraft approach trim angle of attack is selected as the aircraft angle of attack corresponding to the maximum hinge moment.

6. The method for determining the maximum hinge moment of the rudder of a transport aircraft according to claim 5, characterized in that: The aircraft approach trim angle of attack is selected to be 3 degrees.

7. The method for determining the maximum hinge moment of the rudder of a transport aircraft according to claim 1, characterized in that: 0 degrees is selected as the sideslip angle corresponding to the maximum hinge moment.

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