Method for determining maximum hinge moment of elevator of transport aircraft
By combining the elevator hinge torque calculation formula with aircraft speed and angle of attack deviation, the maximum elevator hinge torque can be quickly determined, solving the complexity of hinge torque determination in aircraft design and enabling accurate control surface actuator design in the absence of full envelope data.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN AIRCRAFT DESIGN INST OF AVIATION IND OF CHINA
- Filing Date
- 2023-12-12
- Publication Date
- 2026-06-26
AI Technical Summary
During the aircraft design phase, existing technologies make it difficult to quickly and accurately determine the maximum hinge torque of the elevator, especially in the absence of full flight envelope and configuration data, which leads to difficulties in the design of control surface actuators.
The elevator hinge torque is calculated using the formula Mh=Ch(α,δe)qSδbδ. Combined with the aircraft speed, angle of attack and elevator deflection, the maximum elevator hinge torque is calculated by determining the maneuvering speed and trim angle of attack (6°). The maximum hinge torque is selected as the one with the largest absolute value of the hinge torque corresponding to the limit positive deflection and the limit negative deflection.
The ability to quickly and accurately determine the maximum hinge torque of the elevator during the aircraft design phase simplifies the design of control surface actuators and improves the accuracy and efficiency of the results.
Smart Images
Figure CN117669055B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of aircraft operation and control, and specifically relates to a method for determining the maximum hinge torque of the elevator of a transport aircraft. Background Technology
[0002] The maximum hinge moment is an important design input for aircraft flight control system design. The magnitude of the maximum hinge moment of each control surface has a significant impact on the design of the control surface actuators. It not only determines the weight and size of the actuators, but also affects the arrangement of the actuators in the aircraft. Therefore, determining the maximum hinge moment is an important task in aircraft design.
[0003] Determining the maximum hinge moment of the elevator typically requires combining hinge moment coefficients obtained through aerodynamic numerical calculations or wind tunnel testing. This involves extensive calculations of the hinge moments under various maneuvers across the entire flight envelope, with a maximum hinge moment value selected based on the results. This calculation method is quite complex, requiring design inputs for the control surface deflection curves and the flight envelope, as well as all the data for the hinge moment coefficients. In the aircraft design phase, the control surface deflection curves have not yet been designed, and wind tunnel testing of the hinge moment has not been conducted. Therefore, a comprehensive and detailed set of hinge moment coefficients is lacking. Thus, it is crucial to quickly obtain a relatively accurate maximum hinge moment during the aircraft design phase. Summary of the Invention
[0004] The purpose of this application is to provide a method for determining the maximum hinge torque of the elevator of a transport aircraft, so as to solve or alleviate at least one of the problems in the prior art.
[0005] The technical solution of this application is: a method for determining the maximum hinge torque of the elevator of a transport aircraft, the method comprising the following steps:
[0006] Determine the calculation formula for the elevator hinge torque of the aforementioned transport aircraft;
[0007] Determine the aircraft speed at which the maximum elevator hinge moment occurs, and determine the calculation parameters corresponding to the maximum elevator hinge moment based on the aircraft speed. The calculation parameters include the aircraft angle of attack and elevator deflection.
[0008] Based on the elevator hinge torque calculation formula and the calculation parameters corresponding to the maximum elevator hinge torque, two hinge torques corresponding to the elevator deflection as the limit positive deflection and the limit negative deflection are obtained respectively. The link torque with the largest absolute value among the two hinge torque results is selected as the maximum elevator hinge torque.
[0009] In a preferred embodiment of this application, the formula for calculating the elevator hinge torque of the transport aircraft is:
[0010] M h =Ch (α、δ e )qS δ b δ
[0011] Where: M h Elevator hinge torque;
[0012] C h Here is the elevator hinge moment coefficient, which is the aircraft angle of attack α and elevator deflection δ. e The function;
[0013] q represents the rapid pressure;
[0014] S δ b δ These are the elevator reference area and reference length, respectively.
[0015] In a preferred embodiment of this application, the maneuvering speed is selected as the aircraft speed corresponding to the maximum hinge torque of the elevator.
[0016] In a preferred embodiment of this application, the trim angle of attack corresponding to the maneuvering speed is selected as the aircraft angle of attack corresponding to the maximum hinge moment of the elevator.
[0017] In a preferred embodiment of this application, the trim angle of attack is 6 degrees.
[0018] The method for determining the maximum hinge moment of the elevator of a transport aircraft proposed in this application only requires the aircraft angle of attack and elevator deflection corresponding to the maximum hinge moment of the elevator to quickly calculate the maximum hinge moment. The maximum hinge moment of the elevator can be quickly calculated without performing full envelope and full configuration hinge moment calculations. This method is suitable for determining the maximum hinge moment of the elevator during the aircraft design phase, and the results have high accuracy. Attached Figure Description
[0019] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.
[0020] Figure 1 This is a schematic diagram illustrating the method for determining the maximum hinge torque of the elevator of a transport aircraft as described in this application. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.
[0022] In order to quickly and accurately obtain the maximum hinge torque of the elevator when there are few input conditions in the design phase, this application proposes a method for rapidly determining the maximum hinge torque of the elevator of transport aircraft, which can quickly give the maximum hinge torque of the elevator without performing full envelope full configuration hinge torque calculation.
[0023] like Figure 1 As shown, the method for determining the maximum hinge torque of the elevator of a transport aircraft provided in the application includes the following steps:
[0024] Step 1: Determine the calculation formula for the elevator hinge torque of the transport aircraft. The calculation formula for the elevator hinge torque is as follows:
[0025] M h =C h (α、δ e )qS δ b δ
[0026] Where: M h Elevator hinge torque;
[0027] C h Here is the elevator hinge moment coefficient, which is the aircraft angle of attack α and elevator deflection δ. e The function;
[0028] q represents the rapid pressure;
[0029] S δ b δ These are the elevator reference area and reference length (mean chord length), respectively.
[0030] Step 2: Determine the aircraft speed at which the maximum elevator hinge torque occurs, and determine the calculation parameters corresponding to the maximum elevator hinge torque based on the aircraft speed. The calculation parameters include the aircraft angle of attack and elevator deflection.
[0031] The elevator hinge moment coefficient varies with the aircraft angle of attack and elevator deflection at a negative rate.
[0032] During longitudinal maneuvers, the elevator deflects upward, increasing the angle of attack; conversely, it deflects downward, decreasing the angle of attack. Therefore, for the elevator, the extreme value of the hinge moment coefficient occurs at the angle of attack state corresponding to the start of the maneuver.
[0033] At a given altitude and speed, the extreme values of the elevator hinge moment coefficient occur in the following states:
[0034] 1) The angle of attack is the angle of attack for trimming under given conditions;
[0035] 2) The elevator has the upper and lower limit deflection.
[0036] Typically, the calculation of the maximum hinge moment of the elevator requires consideration of various typical weights, aircraft configurations, different flight speed and altitude envelopes, the angle of attack is the trim angle of attack under given conditions, and the elevator is the upper and lower limit deflection. A large number of calculations are performed using the elevator hinge moment calculation formula, and then a maximum hinge moment value is selected from the calculation results.
[0037] Among them, the speed of movement V A The regulations are as follows: V A Not less than
[0038] In the formula, V SI Let n be the stall velocity with the flaps retracted, and n be V. C The positive limiting motor load factor, V C Designed for cruising speed.
[0039] The longitudinal elevator deflection curve shows that the maximum elevator deflection angle decreases as speed increases, while at low speeds, the maximum elevator deflection is a fixed value. The inflection point of the elevator deflection curve typically occurs near the maximum flight weight maneuvering speed. Based on model experience, since elevator deflection has a significant impact on hinge torque, the inflection point of the elevator deflection curve (where the elevator deflection is at its maximum) is the point of maximum hinge torque. During high-speed flight, although the flight speed increases, the maximum elevator deflection angle decreases, and its hinge torque is not at its maximum value.
[0040] Although the elevator hinge moment coefficient changes negatively with the aircraft angle of attack, the decrease is small as the angle of attack increases. Therefore, in this application, the trim angle of attack corresponding to the maneuvering speed is preferably taken as 6° when calculating the hinge moment.
[0041] In summary, when rapidly calculating the maximum hinge moment of the elevator during the design phase in this application, the speed of the aircraft with the maximum flight weight (i.e., the maneuvering speed) is determined. The calculation parameters corresponding to this aircraft speed are the elevator deflection, which is taken as the limit positive deflection and the limit negative deflection, and the angle of attack, which is taken as the trim angle of attack corresponding to the maneuvering speed. Preferably, the trim angle of attack is taken as 6°.
[0042] Step 3: Based on the elevator hinge torque calculation formula and the calculation parameters corresponding to the maximum elevator hinge torque determined in the above process, obtain the hinge torques corresponding to the limit positive deflection and the limit negative deflection respectively. Select the hinge torque with the largest absolute value among the two hinge torque results as the maximum elevator hinge torque.
[0043] Based on the elevator hinge torque calculation formula, the maneuvering speed V determined in step two is used. ATrim the angle of attack to 6° and determine the elevator's maximum positive and negative deflection. Calculate the hinge torque corresponding to the elevator's maximum positive and negative deflection respectively. Select the larger absolute value between the hinge torque corresponding to the elevator's maximum positive and negative deflection as the elevator's maximum hinge torque.
[0044] For example, in this embodiment of the application, a rapid calculation of the maximum hinge moment of the elevator is required during the design phase of a certain type of transport aircraft. The known calculation parameters of the rapid calculation method for the maximum hinge moment of the elevator proposed in this application are as follows:
[0045] The aircraft has a maximum takeoff weight of 30,000 kg. The maneuvering speed of 310 km / h corresponding to this maximum takeoff weight is selected as the aircraft speed corresponding to the maximum elevator hinge moment. The angle of attack is taken as the trim angle of attack corresponding to the maneuvering speed, preferably 6°. The elevator deflection is selected as the aircraft's limit positive deflection of 20° and limit negative deflection of -25° as the elevator deflection for the maximum hinge moment calculation.
[0046] According to formula M h =C h (α、δ e )qS δ b δ Substituting the known calculated parameters—trimming angle of attack of 6°, elevator maximum positive deflection of 20°, and elevator maximum negative deflection of -25°—into the hinge moment coefficient data, the hinge moment coefficient corresponding to elevator maximum positive deflection of 20° is found to be -0.22, and the hinge moment coefficient corresponding to elevator maximum negative deflection of -25° is found to be 0.26. The reference area S of the aircraft's elevator... δ It is 2.1m 2 Elevator reference length (mean chord length) b δ 0.6m 2 The hinge torque corresponding to the elevator's extreme positive deflection is calculated to be 1259 N·m, and the hinge torque corresponding to the elevator's extreme negative deflection is calculated to be -1488 N·m. The larger absolute value is selected between these two values; therefore, the maximum hinge torque of the elevator is -1488 N·m.
[0047] The method for rapidly determining the maximum hinge moment of the elevator in transport aircraft proposed in this application only requires the aircraft speed, angle of attack, and elevator deflection corresponding to the maximum hinge moment of the elevator to perform rapid calculation of the maximum hinge moment. The maximum hinge moment of the elevator can be quickly calculated without performing full envelope and full configuration hinge moment calculation. This method is suitable for determining the maximum hinge moment of the elevator during the aircraft design phase, and the results have high accuracy.
[0048] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A method for determining the maximum hinge torque of the elevator of a transport aircraft, characterized in that, The method includes the following steps: Determine the calculation formula for the elevator hinge torque of the aforementioned transport aircraft; The aircraft speed at which the maximum elevator hinge moment occurs is determined, and the calculation parameters corresponding to the maximum elevator hinge moment are determined based on the aircraft speed. The calculation parameters include the aircraft angle of attack and the elevator deflection. The maneuvering speed is selected as the aircraft speed corresponding to the maximum elevator hinge moment, and the trim angle of attack corresponding to the maneuvering speed is selected as the aircraft angle of attack corresponding to the maximum elevator hinge moment. The trim angle of attack is 6 degrees. Based on the elevator hinge torque calculation formula and the calculation parameters corresponding to the maximum elevator hinge torque, two hinge torques corresponding to the elevator deflection as the limit positive deflection and the limit negative deflection are obtained respectively. The link torque with the largest absolute value among the two hinge torque results is selected as the maximum elevator hinge torque.
2. The method for determining the maximum hinge torque of the elevator of a transport aircraft as described in claim 1, characterized in that, The formula for calculating the elevator hinge torque of the transport aircraft is as follows: ； Where: M h Elevator hinge torque; C h Here is the elevator hinge moment coefficient, which is the aircraft angle of attack α and elevator deflection δ. e The function; q represents the rapid pressure; S δ b δ These are the elevator reference area and reference length, respectively.