Design method and device of fully movable horizontal tail for ultra-low-speed tail-wheel propeller aircraft

Abstract

The present invention discloses a method and device for designing a fully movable horizontal tail for an ultra-low-speed tail-type propeller aircraft. The method comprises: S1, formulating a criterion for determining longitudinal control characteristics; S2, selecting an initial design base airfoil based on a low-speed symmetrical airfoil and trade-off factors; S3, designing a fully movable horizontal tail based on the initial design base airfoil; S4, determining the deflection angle range of the fully movable horizontal tail, calculating the trim angle of the horizontal tail at different cruise angles of attack, and determining whether sufficient control margin remains after trimming. If not, execute S2; if so, execute S5; S5, calculating the longitudinal control characteristics of the aircraft based on the fully movable horizontal tail, determining whether the longitudinal control characteristics meet the longitudinal control characteristics determination criterion; if not, execute S2; if so, terminate the design and determine the parameters of the fully movable horizontal tail. The present invention minimizes the structural weight of the aircraft while ensuring that the aircraft has good longitudinal maneuverability and stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft design, and more specifically, relates to a design method and device for a fully movable horizontal tail of an ultra-low-speed tailwheel propeller aircraft. Background Art

[0002] As a key aerodynamic control surface in aircraft design, the all-moving horizontal tail plays a vital role in the aircraft's maneuverability and stability. For propeller aircraft, the slipstream generated by the propeller has a significant impact on the aircraft's aerodynamic characteristics. The propeller slipstream will change the aircraft's lift, drag, and downwash characteristics, thereby affecting the aircraft's maneuverability, stability, and control surface efficiency. The slipstream effect often reduces the aircraft's pitch static stability. During the design process, the impact of the propeller slipstream must be considered to ensure the aircraft's stability and maneuverability in full-profile flight. In addition, the design must also take into account the needs of the aircraft's weight reduction design. According to the concept of lightweight design, the structural weight optimization iterative design is carried out to minimize the aircraft's structural weight while ensuring the aircraft has good longitudinal maneuverability and stability.

[0003] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft, so as to reduce the structural weight of the aircraft as much as possible while ensuring good longitudinal maneuverability and stability of the aircraft.

[0005] To achieve the above-mentioned object, the present invention proposes a method and device for designing a fully movable horizontal tail for an ultra-low-speed tailwheel propeller aircraft.

[0006] According to a first aspect of the present invention, a method for designing a fully movable horizontal tail for an ultra-low-speed tailwheel propeller aircraft is proposed, comprising:

[0007] S1. Establish criteria for determining longitudinal handling characteristics;

[0008] S2, select the initial design base airfoil based on the low-speed symmetrical airfoil and trade-off factors;

[0009] S3. Designing a fully movable horizontal tailplane based on the initial designed basic airfoil;

[0010] S4. Determine the deflection angle range of the all-movable horizontal stabilizer, calculate the horizontal stabilizer trim angles at different cruise angles of attack, and determine whether sufficient control margin remains after trimming. If not, execute S2; if so, execute S5.

[0011] S5. Calculate the longitudinal control and stability characteristics of the aircraft based on the all-movable horizontal stabilizer, and determine whether the longitudinal control and stability characteristics meet the longitudinal control and stability characteristics determination criteria. If not, execute S2. If so, terminate the design and determine the parameters of the all-movable horizontal stabilizer.

[0012] Optionally, the longitudinal handling stability determination criteria include:

[0013] Longitudinal static stability margin requirements, short-period and long-period motion modal response types and characteristic parameter requirements.

[0014] Optionally, selecting an initial design basic airfoil based on the low-speed symmetrical airfoil and trade-off factors includes:

[0015] Calculate the lift, drag and stall characteristics of different low-speed symmetrical airfoils within a given Reynolds number range;

[0016] Based on the calculation results and the trade-off factors, a comparison and balance is performed to select the optimal airfoil of the all-moving horizontal tail.

[0017] Optionally, designing a fully movable horizontal tail based on the initial designed basic airfoil includes:

[0018] Selecting a tailplane type of the all-moving tailplane based on weight factors;

[0019] Designing the longitudinal position of the all-movable horizontal stabilizer on the fuselage based on the shared structural joint between the all-movable horizontal stabilizer, the fuselage, and the vertical stabilizer;

[0020] Determining reference values ​​of the capacity of the all-moving horizontal tail and vertical tail based on engineering experience;

[0021] Determining the requirements for the horizontal and vertical tail areas and the rear fuselage length of the all-movable horizontal and vertical tail at different lateral positions of the fuselage based on the reference values ​​of the tail capacities of the all-movable horizontal and vertical tail;

[0022] estimating the total weight of the rear fuselage, the all-movable horizontal stabilizer and the vertical stabilizer at different lateral positions of the fuselage based on the weight coefficient;

[0023] determining a lateral position of the all-movable horizontal stabilizer on the fuselage based on the gross weight;

[0024] The tailplane span, mean chord length, and tip-toe ratio of the all-movable horizontal stabilizer are determined based on the lateral and longitudinal positions of the all-movable horizontal stabilizer on the fuselage, taking into account the stall characteristics of the tailplane, the controllable stability characteristics after the influence of propeller slipstream, and the structural weight.

[0025] Optionally, determining the tailplane span, mean chord length, and tip-to-base ratio of the all-movable tailplane based on the lateral and longitudinal positions of the all-movable tailplane relative to the fuselage and taking into account the tailplane stall characteristics, the controllable stability characteristics after the influence of propeller slipstream, and the structural weight includes:

[0026] Based on the tail capacity of the all-moving horizontal stabilizer, design the tail extension length and average chord length schemes under different aspect ratios;

[0027] Calculating the rear limit of the center of gravity under each of the schemes based on the longitudinal static stability margin requirement;

[0028] Select the solution that meets the set requirements based on the calculation results;

[0029] A reasonable tip-to-root ratio range is selected, and the lift characteristics and structural weight of different tip-to-root ratio schemes are comprehensively considered to set the tip-to-root ratio of the all-moving horizontal tail.

[0030] Optionally, determining the deflection angle range of the all-moving horizontal stabilizer includes:

[0031] The deflection angle range of the all-movable horizontal tail is determined based on a constraint condition that the local angle of attack does not exceed the stall angle of attack of the horizontal tail when the all-movable horizontal tail is deflected during full-profile trim flight.

[0032] Optionally, the S5 specifically includes:

[0033] evaluating the lift characteristics, torque characteristics, and stall characteristics of the all-moving horizontal stabilizer based on the horizontal stabilizer span, mean chord length, and tip-to-root ratio of the all-moving horizontal stabilizer;

[0034] Analyze the changes in the local speed and angle of attack of the all-moving horizontal tail under the influence of slipstream, and calculate the longitudinal static stability margin and motion modal characteristics of the aircraft;

[0035] Determine whether the longitudinal static stability margin and motion modal characteristics of the aircraft meet the longitudinal control stability characteristics judgment criteria. If not, execute S2. If so, end the design and determine the parameters of the all-moving horizontal stabilizer.

[0036] Optionally, the setting requirements include:

[0037] Taking into account the effect of propeller slipstream on static stability, a margin for setting a time limit after calculating the center of gravity is reserved;

[0038] The calculation result exceeds the front limit of the center of gravity calculated according to the anti-rollover angle of the main landing gear, and retains a certain range of center of gravity variation;

[0039] The aspect ratio of the solution is minimal.

[0040] Optionally, the weighing factors include:

[0041] The maximum lift coefficient, lift line slope, stall angle of attack, lift-to-drag ratio, whether the stall process is smooth and whether the lift line slope linearity is good.

[0042] According to a second aspect of the present invention, a fully movable horizontal tail design device for an ultra-low-speed tail-wheel propeller aircraft is provided, comprising:

[0043] A development module for developing criteria for determining longitudinal handling characteristics;

[0044] A selection module is used to select the initial design base airfoil based on the low-speed symmetric airfoil and trade-off factors;

[0045] A design module is used to design a full-moving horizontal tail based on the initial design basic airfoil;

[0046] a determination, calculation, and judgment module, configured to determine the deflection angle range of the all-moving horizontal stabilizer, calculate the horizontal stabilizer trim angles at different cruise angles of attack, and determine whether sufficient control margin remains after trimming. If not, the system returns to the selection module; if so, the system returns to the judgment module;

[0047] a judgment module configured to calculate the longitudinal control and stability characteristics of the aircraft based on the all-movable horizontal stabilizer, and determine whether the longitudinal control and stability characteristics meet the longitudinal control and stability characteristics judgment criteria; if not, returning to the selection module; if so, terminating the design and determining the parameters of the all-movable horizontal stabilizer.

[0048] The beneficial effects of the present invention are as follows: the present invention formulates a longitudinal control and stability characteristic judgment criterion, designs a fully movable horizontal tail based on the longitudinal control and stability characteristic judgment criterion, ensures that the aircraft has good longitudinal maneuverability and stability, refines and clarifies the trade-off factors in the design process, makes the design process clearer, and comprehensively considers the influence of aerodynamics, control and stability, so as to make the aircraft tail lighter.

[0049] The system of the present invention has other features and advantages that will be apparent from or will be described in detail in the accompanying drawings and subsequent detailed description incorporated herein, which together serve to explain the specific principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings, in which like reference numerals generally represent like components.

[0051] Figure 1 A flow chart showing the steps of a method for designing a fully movable horizontal tailplane for an ultra-low-speed tailwheel propeller aircraft according to the present invention is provided.

[0052] Figure 2 A flowchart showing the steps of a method for designing a fully movable horizontal tailplane for an ultra-low-speed tailwheel propeller aircraft according to a first embodiment of the present invention is shown. DETAILED DESCRIPTION

[0053] The present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention may be implemented in various forms and is not limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present invention more thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0054] like Figure 1 As shown, a method for designing a fully movable horizontal tail of an ultra-low-speed tailwheel propeller aircraft according to the present invention includes:

[0055] S1. Establish criteria for determining longitudinal handling characteristics;

[0056] S2, select the initial design base airfoil based on the low-speed symmetrical airfoil and trade-off factors;

[0057] S3. Design a fully movable horizontal tail based on the initial design basic airfoil;

[0058] S4. Determine the deflection angle range of the all-movable horizontal stabilizer and calculate the horizontal stabilizer trim angle at different cruise angles of attack. Determine whether sufficient control margin remains after trimming. If not, proceed to S2. If so, proceed to S5.

[0059] S5. Calculate the aircraft's longitudinal control and stability characteristics based on the all-movable horizontal stabilizer and determine whether the longitudinal control and stability characteristics meet the longitudinal control and stability characteristics determination criteria. If not, execute S2. If so, terminate the design and determine the parameters of the all-movable horizontal stabilizer.

[0060] Specifically, the present invention formulates a longitudinal control stability characteristic judgment criterion and designs a fully movable horizontal tail based on the longitudinal control stability characteristic judgment criterion to ensure that the aircraft has good longitudinal maneuverability and stability; selects an initial design basic airfoil from low-speed symmetrical airfoils, and determines the optimal airfoil based on trade-off factors; designs the basic plane dimensions of the fully movable horizontal tail, and gives the full-moving horizontal tail's upper and lower fore-and-aft position, span, average chord length, and tip-root ratio; determines the deflection angle limit range of the fully movable horizontal tail, and calculates the horizontal tail trim angle at different cruise angles of attack, and determines whether there is sufficient control margin after trimming to preliminarily evaluate the controllability of the fully movable horizontal tail. If there is not sufficient control margin, the controllable capability of the fully movable horizontal tail is preliminarily evaluated. If the control margin is sufficient, the optimal airfoil is re-determined for design. If the control margin is sufficient, the longitudinal control and stability characteristics of the aircraft are calculated based on the designed all-movable horizontal tail, and it is determined whether the longitudinal control and stability characteristics meet the established longitudinal control and stability characteristics judgment criteria. If not, the optimal airfoil is re-determined for design until the longitudinal control and stability characteristics judgment criteria are met. If so, the design is completed and the parameters of the designed all-movable horizontal tail are determined. On the basis of ensuring that the aircraft has good longitudinal control and stability, the present invention comprehensively considers the effects of aerodynamics, control and stability, makes the aircraft tail wing lighter, and reduces the structural weight of the aircraft as much as possible.

[0061] In one example, longitudinal handling characteristics determination criteria include:

[0062] Longitudinal static stability margin requirements, short-period and long-period motion modal response types and characteristic parameter requirements.

[0063] Specifically, longitudinal static stability margin refers to the ratio of the distance between the aircraft's center of gravity and the neutral point (the aircraft's focal point) to the mean aerodynamic chord length. It is a key parameter for measuring an aircraft's longitudinal static stability. When an aircraft has a positive longitudinal static stability margin, it means that after an external disturbance causes a change in angle of attack, the aircraft can automatically generate a restoring torque to return the aircraft to its original equilibrium state. This is crucial for flight safety, especially during cruise, takeoff, and landing, where it effectively prevents dangerous situations such as stalls. Short-period motion is a major mode of longitudinal aircraft motion, manifesting as rapid oscillations in the aircraft's pitch angle and angle of attack. It is primarily determined by the aircraft's pitch damping and pitch stiffness. Long-period motion, also known as heaving and swaying motion, primarily involves slow changes in the aircraft's altitude and speed. It is caused by an imbalance between the aircraft's weight and lift, and typically manifests as periodic variations in the aircraft's altitude and speed, which are much slower than short-period motion.

[0064] In one example, an initial design base airfoil is selected based on a low-speed symmetric airfoil and trade-offs include:

[0065] Calculate the lift, drag and stall characteristics of different low-speed symmetrical airfoils within a given Reynolds number range;

[0066] Based on the calculation results and trade-off factors, the optimal airfoil of the full-moving horizontal tail is selected.

[0067] In one example, designing a fully movable horizontal tailplane based on an initial design base airfoil includes:

[0068] Based on weight considerations, the horizontal tail type of the full-motion horizontal tail is selected;

[0069] The longitudinal position of the all-movable horizontal stabilizer on the fuselage is designed based on the shared structural joints between the all-movable horizontal stabilizer, the fuselage, and the vertical stabilizer.

[0070] Determine the reference values ​​of the all-moving horizontal and vertical tail capacities based on engineering experience;

[0071] Determine the required horizontal and vertical tail area and rear fuselage length for the fully movable horizontal and vertical tail at different lateral positions on the fuselage based on the reference values ​​of the tail capacity of the fully movable horizontal and vertical tail;

[0072] Estimate the total weight of the rear fuselage, all-movable horizontal stabilizer and vertical stabilizer at different lateral positions of the fuselage based on the weight coefficient;

[0073] Determine the lateral position of the all-movable horizontal stabilizer on the fuselage based on the gross weight;

[0074] Based on the lateral and longitudinal positions of the all-moving horizontal stabilizer on the fuselage, the horizontal stabilizer stall characteristics, the controllable stability characteristics after the influence of propeller slipstream and the structural weight are comprehensively considered to determine the horizontal stabilizer span, average chord length and tip-toe ratio of the all-moving horizontal stabilizer.

[0075] In one example, based on the lateral and longitudinal positions of the all-moving horizontal stabilizer on the fuselage, and taking into account the horizontal stabilizer's stall characteristics, the controllable stability characteristics after the influence of propeller slipstream, and the structural weight, the horizontal stabilizer span, mean chord length, and tip-toe ratio of the all-moving horizontal stabilizer are determined as follows:

[0076] Based on the tail capacity of the all-moving horizontal stabilizer, design the horizontal stabilizer span and average chord length schemes under different aspect ratios;

[0077] Calculate the rear limit of the center of gravity under each scheme based on the longitudinal static stability margin requirements;

[0078] Select the solution that meets the set requirements based on the calculation results;

[0079] Select a reasonable tip-to-root ratio range, comprehensively consider the lift characteristics and structural weight of different tip-to-root ratio schemes, and set the tip-to-root ratio of the full-moving horizontal tail.

[0080] In one example, determining the deflection angle range of the all-moving horizontal stabilizer includes:

[0081] The deflection angle range of the all-moving horizontal tail is determined with the constraint that the local angle of attack does not exceed the stall angle of attack of the horizontal tail when the all-moving horizontal tail is deflected during full-profile trim flight.

[0082] In one example, S5 specifically includes:

[0083] The lift, torque and stall characteristics of the all-moving horizontal tail are evaluated based on its horizontal tail span, mean chord length and tip-to-root ratio;

[0084] Analyze the changes in local speed and angle of attack of the all-moving horizontal tail under the influence of slipstream, and calculate the longitudinal static stability margin and motion modal characteristics of the aircraft;

[0085] Determine whether the aircraft's longitudinal static stability margin and motion modal characteristics meet the longitudinal control stability characteristics judgment criteria. If not, execute S2. If so, end the design and determine the parameters of the all-moving horizontal tail.

[0086] In one example, setting requirements includes:

[0087] Considering the effect of propeller slipstream on static stability, a time-limited margin is reserved after calculating the center of gravity;

[0088] The calculated result exceeds the front limit of the center of gravity calculated according to the anti-rollover angle of the main landing gear, and retains a certain range of center of gravity variation;

[0089] The aspect ratio of the scheme is the smallest.

[0090] In one example, the trade-offs include:

[0091] The maximum lift coefficient, lift line slope, stall angle of attack, lift-to-drag ratio, whether the stall process is smooth and whether the lift line slope linearity is good.

[0092] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present invention may be combined with each other.

[0093] Example 1

[0094] like Figure 2 As shown, this embodiment provides a method for designing a fully movable horizontal tail for an ultra-low-speed tailwheel propeller aircraft, comprising:

[0095] Step 1: Establish criteria for determining longitudinal control and stability characteristics. These criteria should clearly define the longitudinal static stability margin requirements. A requirement can be that the longitudinal static stability margin at the aft limit of the center of gravity after the influence of the superimposed slipstream is no less than 10%. The short- and long-period modal response types and characteristic parameter requirements can be clearly defined. Constraints can refer to the Level 1 flight quality requirements of the Manned Aircraft Flight Quality Specification.

[0096] Step 2: Select the initial design base airfoil from the low-speed symmetrical airfoils. You can choose NACA airfoils, such as NACA0009 and NACA0012. Calculate the lift, drag, and stall characteristics of different airfoils within a given Reynolds number range. Compare and weigh the calculated results to select the optimal airfoil. The trade-offs include the maximum lift coefficient, lift line slope, stall angle of attack, lift-to-drag ratio, whether the stall process is gentle, and whether the lift line slope is linear.

[0097] Step 3: Design the basic plane dimensions of the all-moving horizontal stabilizer, and give the up-down, fore-and-aft position, span, average chord length, and tip-toe ratio of the all-moving horizontal stabilizer.

[0098] Step 3-1: Determine the vertical and horizontal positions of the fully movable horizontal tail using the tail capacity method and weight optimization results. First, consider the weight factor to select the horizontal tail type, avoid cross-tail and T-tail, and choose a design that shares structural joints with the fuselage and vertical tail. Secondly, set the reference value of the tail capacity of the horizontal tail and vertical tail based on engineering experience. The tail capacity should be determined based on the size of the aircraft wing area, and 0.5 can be selected. Subsequently, appropriate adjustments are made based on the static stability results to obtain the horizontal tail area and rear fuselage length requirements at different vertical and horizontal tail positions. Use the weight coefficient to estimate the rear fuselage and horizontal tail weight at different vertical and horizontal tail positions. Compare the weight results at different vertical and horizontal positions, and select the lightest weight solution to design the horizontal tail layout.

[0099] Step 3-2: Based on the horizontal tail position designed in Step 3-1, determine the horizontal tail span, mean chord length, and tip-to-root ratio by considering the horizontal tail stall characteristics, handling characteristics after the influence of propeller slipstream, and structural weight. Referencing the horizontal tail capacity in Step 3-1, design horizontal tail span and mean chord length options for different aspect ratios. Aspect ratios can range from 3 to 7. Calculate the aft center of gravity limits for different options based on the static stability margin requirements in Step 1. The calculation should consider the effect of propeller slipstream on static stability and allow for a margin of 3% to 5%. The calculated result should exceed the forward center of gravity limit calculated based on the main landing gear anti-roll angle, while maintaining a certain range of center of gravity variation. Select the option with the smaller aspect ratio among the options that meet the requirements. Select a reasonable tip-to-root ratio range, preferably 0.4 to 0.7. Consider the lift characteristics and structural weight of different tip-to-root ratio options to determine the appropriate tip-to-root ratio.

[0100] Step 4: Determine the deflection angle limit range of the all-moving horizontal stabilizer and preliminarily evaluate the controllability of the all-moving horizontal stabilizer.

[0101] Step 4-1. Define the deflection angle range of the fully movable horizontal tail using the constraint that the local angle of attack when the fully movable horizontal tail is deflected does not exceed the horizontal tail stall angle of attack during fully trimmed flight.

[0102] Step 4-2: Calculate the horizontal tail trim angle at different cruise angles of attack and determine whether there is sufficient control margin after trimming. The control margin at the maximum / minimum angle of attack can be selected to be no less than 3° to 5°. If not, return to step 2; if so, proceed to step 5.

[0103] Step 5: Verify and confirm aerodynamic and control stability characteristics. Based on the fully movable horizontal tail determined in Step 3-2, evaluate the horizontal tail's lift, torque, and stall characteristics. Analyze the changes in the horizontal tail's local speed and angle of attack under the influence of slipstream. Calculate the aircraft's longitudinal static stability margin and kinematic modal characteristics. Determine whether the criteria in Step 1 are met. If so, the design is complete. If not, return to Step 2.

[0104] Example 2

[0105] This embodiment provides a fully movable horizontal tail design device for an ultra-low-speed tail-wheel propeller aircraft, comprising:

[0106] A development module for developing criteria for determining longitudinal handling characteristics;

[0107] A selection module is used to select the initial design base airfoil based on the low-speed symmetric airfoil and trade-off factors;

[0108] Design module, used to design a fully movable horizontal tail based on the initial design basic airfoil;

[0109] The determination, calculation, and judgment module is used to determine the deflection angle range of the all-moving horizontal stabilizer and calculate the horizontal stabilizer trim angle at different cruise angles of attack. It is then determined whether there is sufficient control margin after trimming. If not, the module returns to the selection module. If so, the module returns to the judgment module.

[0110] The judgment module is used to calculate the longitudinal control and stability characteristics of the aircraft based on the all-movable horizontal tail and determine whether the longitudinal control and stability characteristics meet the longitudinal control and stability characteristics judgment criteria. If not, the module returns to the selection module. If so, the design is completed and the parameters of the all-movable horizontal tail are determined.

[0111] While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft, characterized in that: include: S1. Establish criteria for determining longitudinal handling characteristics; S2, select the initial design base airfoil based on the low-speed symmetrical airfoil and trade-off factors; S3. Designing a fully movable horizontal tailplane based on the initial designed basic airfoil; S4. Determine the deflection angle range of the all-movable horizontal stabilizer, calculate the horizontal stabilizer trim angles at different cruise angles of attack, and determine whether sufficient control margin remains after trimming. If not, execute S2; if so, execute S5. S5. Calculate the longitudinal control and stability characteristics of the aircraft based on the all-movable horizontal stabilizer, and determine whether the longitudinal control and stability characteristics meet the longitudinal control and stability characteristics determination criteria. If not, execute S2. If so, terminate the design and determine the parameters of the all-movable horizontal stabilizer.

2. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 1, characterized in that: The longitudinal handling stability characteristics judgment criteria include: Longitudinal static stability margin requirements, short-period and long-period motion modal response types and characteristic parameter requirements.

3. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 2, characterized in that: The selection of the initial design basic airfoil based on the low-speed symmetrical airfoil and trade-off factors includes: Calculate the lift, drag and stall characteristics of different low-speed symmetrical airfoils within a given Reynolds number range; Based on the calculation results and the trade-off factors, a comparison and balance is performed to select the optimal airfoil of the all-moving horizontal tail.

4. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 3, characterized in that: The design of the full-moving horizontal tail based on the initial design basic airfoil includes: Selecting a tailplane type of the all-moving tailplane based on weight factors; Designing the longitudinal position of the all-movable horizontal stabilizer on the fuselage based on the shared structural joint between the all-movable horizontal stabilizer, the fuselage, and the vertical stabilizer; Determining reference values ​​of the capacity of the all-moving horizontal tail and vertical tail based on engineering experience; Determining the requirements for the horizontal and vertical tail areas and the rear fuselage length of the all-movable horizontal and vertical tail at different lateral positions of the fuselage based on the reference values ​​of the tail capacities of the all-movable horizontal and vertical tail; estimating the total weight of the rear fuselage, the all-movable horizontal stabilizer and the vertical stabilizer at different lateral positions of the fuselage based on the weight coefficient; determining a lateral position of the all-movable horizontal stabilizer on the fuselage based on the gross weight; The tailplane span, mean chord length, and tip-toe ratio of the all-movable horizontal stabilizer are determined based on the lateral and longitudinal positions of the all-movable horizontal stabilizer on the fuselage, taking into account the stall characteristics of the tailplane, the controllable stability characteristics after the influence of propeller slipstream, and the structural weight.

5. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 4, characterized in that: Determining the tailplane span, mean chord length, and tip-toe ratio of the all-movable tailplane based on the lateral and longitudinal positions of the all-movable tailplane on the fuselage, taking into account the tailplane stall characteristics, the controllable stability characteristics after the influence of propeller slipstream, and the structural weight includes: Based on the tail capacity of the all-moving horizontal stabilizer, design the tail extension length and average chord length schemes under different aspect ratios; Calculating the rear center of gravity limit of each of the schemes based on the longitudinal static stability margin requirement; Select the solution that meets the set requirements based on the calculation results; A reasonable tip-to-root ratio range is selected, and the lift characteristics and structural weight of different tip-to-root ratio schemes are comprehensively considered to set the tip-to-root ratio of the all-moving horizontal tail.

6. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 1, characterized in that: Determining the deflection angle range of the all-moving horizontal stabilizer includes: The deflection angle range of the all-movable horizontal tail is determined based on a constraint condition that the local angle of attack does not exceed the stall angle of attack of the horizontal tail when the all-movable horizontal tail is deflected during full-profile trim flight.

7. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 5, characterized in that: The S5 specifically includes: evaluating the lift characteristics, torque characteristics, and stall characteristics of the all-moving horizontal stabilizer based on the horizontal stabilizer span, mean chord length, and tip-to-root ratio of the all-moving horizontal stabilizer; Analyze the changes in the local speed and angle of attack of the all-moving horizontal tail under the influence of slipstream, and calculate the longitudinal static stability margin and motion modal characteristics of the aircraft; It is determined whether the longitudinal static stability margin and motion modal characteristics of the aircraft meet the longitudinal control stability characteristics judgment criteria. If not, step S2 is executed. If so, the design is terminated and the parameters of the all-moving horizontal stabilizer are determined.

8. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 5, characterized in that: The setup requirements include: Taking into account the effect of propeller slipstream on static stability, a margin for setting a time limit after calculating the center of gravity is reserved; The calculation result exceeds the front limit of the center of gravity calculated according to the anti-rollover angle of the main landing gear, and retains a certain range of center of gravity variation; The aspect ratio of the solution is minimal.

9. The method for designing a fully movable horizontal tail for an ultra-low-speed tail-wheel propeller aircraft according to claim 3, characterized in that: The trade-offs include: The maximum lift coefficient, lift line slope, stall angle of attack, lift-to-drag ratio, whether the stall process is smooth and whether the lift line slope linearity is good.

10. A fully movable horizontal tail design device for an ultra-low-speed tail-wheel propeller aircraft, characterized in that: include: A development module for developing criteria for determining longitudinal handling characteristics; A selection module is used to select the initial design base airfoil based on the low-speed symmetric airfoil and trade-off factors; A design module is used to design a full-moving horizontal tail based on the initial design basic airfoil; a determination, calculation, and judgment module, configured to determine the deflection angle range of the all-moving horizontal stabilizer, calculate the horizontal stabilizer trim angles at different cruise angles of attack, and determine whether sufficient control margin remains after trimming. If not, the system returns to the selection module; if so, the system returns to the judgment module; a judgment module configured to calculate the longitudinal control and stability characteristics of the aircraft based on the all-movable horizontal stabilizer, and determine whether the longitudinal control and stability characteristics meet the longitudinal control and stability characteristics judgment criteria; if not, returning to the selection module; if so, terminating the design and determining the parameters of the all-movable horizontal stabilizer.

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