An aircraft longitudinal static stability low-speed dynamic demonstration device

Abstract

The present invention discloses a low-speed dynamic demonstration device for the longitudinal static stability of an aircraft. The device includes: an aircraft model, which includes: a nose, a fuselage, a tail, wings, a small horizontal tail or a large horizontal tail, a horizontal tail rotation axis, a horizontal tail sliding axis, a central sliding axis, a weight module, an engine, a vertical tail; a connection and support device for supporting and fixing the aircraft model; and a uniform wind field device for providing a uniform wind field for the aircraft model. The device of the present invention can provide experimental data for studying the low-speed dynamic longitudinal static stability of an aircraft, making the abstract longitudinal static stability problem of the aircraft become visualized and specific. The device has a simple structure, simple test operation and convenient use, which can enable students to carry out scientific practice research on the basis of theoretical learning and improve the students' practical innovation ability of hands-on operation; it can also be used as a demonstration prop for popular science activities to intuitively display the scientific principle of the low-speed flight stability of an aircraft through a scaled-down model.

Description

Technical Field

[0001] The present invention belongs to the field of aircraft static stability design and verification experimental devices, and designs an experimental demonstration device that can dynamically display the longitudinal static stability of an aircraft. Background Art

[0002] With the booming development of the aerospace industry, the demand for high-tech talents in aerospace is increasing year by year, and the cultivation of talents in related majors and the intuitive demonstration experiments of professional knowledge have received more and more attention. In the process of introducing the longitudinal static stability of aircraft in courses such as Introduction to Aerospace, Introduction to Aerospace Engineering, and Aerodynamics in aerospace majors of various universities, there is no intelligent teaching aid to demonstrate the relevant content of this knowledge point, so as to realize the intuitive display of complex theoretical principles through experimental means, which is convenient for intuitive and vivid understanding and mastery. At the same time, for the general public, teenagers, and aerospace enthusiasts, how to provide a popular science experimental device for demonstrating the professional knowledge of longitudinal static stability in aerospace popular science activities is also an urgent problem to be solved. Summary of the Invention

[0003] The purpose of the present invention is to solve the above problem of lacking an intelligent teaching aid for teaching, scientific research, and popular science, so as to realize the dynamic demonstration of the low-speed flow field of the longitudinal static stability of the aircraft.

[0004] A low-speed dynamic demonstration device for the longitudinal static stability of an aircraft provided by the present invention can change the angle of attack of the aircraft horizontal tail, the center of gravity of the model aircraft, the distance from the horizontal tail to the center of gravity, and the tail area by adjusting the rotation axis of the aircraft horizontal tail, moving the weight module on the central sliding axis, moving the position of the horizontal tail sliding axis, and replacing the horizontal tail, so as to realize the adjustment, control, and change of the longitudinal static stability of the aircraft, so as to realize the dynamic demonstration of the change law and process of the longitudinal static stability of the aircraft, vividly and intuitively display the principle of the longitudinal static stability of the aircraft, and be used in multiple fields such as teaching, scientific research, and popular science, and can display the scientific knowledge of the longitudinal static stability of the aircraft to primary, middle, and high school students, teenagers, and aerospace enthusiasts.

[0005] The technical solution of the present invention is as follows: A low-speed dynamic demonstration device for the longitudinal static stability of an aircraft, comprising:

[0006] An aircraft model, comprising: a nose, a fuselage, a tail, wings, a small horizontal tail or a large horizontal tail, a horizontal tail rotation axis, a horizontal tail sliding axis, a central sliding axis, a weight module, an engine, and a vertical tail;

[0007] The nose, fuselage, and tail are combined into a cavity with a hollow interior. The small horizontal tail or large horizontal tail is connected to the horizontal tail rotation shaft and is located on both sides of the rear of the fuselage. The horizontal tail sliding shaft and the central sliding shaft are respectively inserted into the interior of the fuselage and are adhesively fixed to the internal structure of the fuselage. According to the demonstration needs, the horizontal tail rotation shaft can be respectively connected to the small horizontal tail or the large horizontal tail to form an integrated body. The small horizontal tail or the large horizontal tail is directly inserted through from both sides on the horizontal tail rotation shaft. The center of the horizontal tail rotation shaft is connected to the horizontal tail sliding shaft, and the center of the horizontal tail rotation shaft moves back and forth along the horizontal tail sliding shaft. The weight module is connected to the central sliding shaft and can slide back and forth on it. The shell of the tail is a flexible rubber soft structure and is separated from the middle gap. The shell is divided into upper and lower parts. The horizontal tail rotation shaft drives the small horizontal tail or the large horizontal tail to move back and forth along the horizontal tail sliding shaft, and the small horizontal tail or the large horizontal tail can simultaneously deflect upward or downward around the horizontal tail rotation shaft. The shell of the tail automatically deforms adaptively with the movement of the horizontal tail rotation shaft.

[0008] Connecting and supporting device for supporting and fixing the aircraft model.

[0009] Uniform wind field device for providing a uniform wind field for the aircraft model.

[0010] Preferably, the connecting and supporting device includes a flat base, inclined support rods, vertical support rods, a support crossbeam, and a rotary connection support. The center of one side of the flat base is fixedly installed with a vertical support rod, and inclined support rods are fixedly installed at both ends of the same side. The support crossbeam is connected to the top of the vertical support rod. The rotary connection support is connected above the axis where the center of gravity of the fuselage is located.

[0011] Preferably, the inclined support rods, vertical support rods, and support crossbeam on the flat base are all made of stainless steel.

[0012] Preferably, the vertical support rod is fixed by inserting it into a small hole on the flat base. The inclined support rod is inserted into a small hole on the flat base, and the top is connected (such as welded) to the top of the vertical support rod to form an integrated body. The support crossbeam is connected (such as welded) to the top of the vertical support rod to form an integrated body.

[0013] Preferably, the nose, fuselage, tail, wings, small horizontal tail, large horizontal tail, and engine are all made of foam material. The nose is connected (such as glued) to the front end of the fuselage to form an integrated body. The wings are connected (such as glued) to both sides of the fuselage to form an integrated body. The engines are respectively connected (such as glued) to the lower sides of both wings to form an integrated body. The tail is connected (such as glued) to the rear end of the fuselage to form an integrated body. The leading edge of the small horizontal tail or the large horizontal tail is inserted into the horizontal tail rotation shaft and moves synchronously with the horizontal tail rotation shaft.

[0014] Preferably, the horizontal tail rotation shaft, the horizontal tail sliding shaft, and the central sliding shaft are all made of carbon fiber with a square cross-section; the central sliding shaft passes through the small hole in the center of the weight module and is inserted and fixed at the central position inside the fuselage; the horizontal tail sliding shaft is inserted into the inside of the fuselage and adhesively fixed to the internal structure of the fuselage; the horizontal tail rotation shaft is connected (such as by glue) to the top of the small horizontal tail or the large horizontal tail to form an integral body and is connected to the horizontal tail sliding shaft.

[0015] The advantages of the present invention are as follows:

[0016] 1. It fills the gap in on-site demonstration teaching, popular science, and research tools for the longitudinal static stability of aircraft. According to preliminary research, in courses such as "Introduction to Aerospace", "Introduction to Aerospace Engineering", "Aerodynamics", and "Flight Mechanics" in the aerospace majors of various universities, there is no relevant model device that can vividly, intuitively, and clearly present the relevant theoretical knowledge of the longitudinal static stability adjustment and change of an aircraft after being disturbed by airflows during flight to the students. However, the present invention can fill this gap, enabling the relevant theoretical knowledge in professional courses to be presented vividly and interestingly, stimulating the students' learning interest and cultivating their love for aerospace aircraft professional knowledge.

[0017] 2. It can simultaneously achieve an intuitive demonstration of the longitudinal static stability adjustment and change through multiple adjustment methods such as center of gravity movement, horizontal tail area adjustment, horizontal tail position movement, and horizontal tail angle of attack change. The present invention can simultaneously adjust multiple components of the model aircraft, change the structural parameters of the model aircraft, and thus change the structural design of the model aircraft. The present invention can simultaneously adjust the horizontal tail rotation shaft, move the weight module along the central sliding shaft, and move the horizontal tail sliding shaft to change the angle of attack of the aircraft's horizontal tail, the center of gravity of the model aircraft, and the distance from the horizontal tail to the center of gravity, generating a restoring moment for the model aircraft, and achieving an intuitive demonstration of changing or adjusting the longitudinal static stability of the aircraft through multiple adjustments.

[0018] 3. The structure designed in the present invention is very simple, easy to use, convenient to install, easy to maintain, and low in cost. Through preliminary experiments, the mass of the model aircraft was too large, resulting in too small a disturbance effect on it caused by the uniform wind field, making the longitudinal instability effect of the aircraft during the teaching demonstration process not obvious enough, affecting the demonstration effects of teaching, popular science, and other functions. Therefore, carbon fiber is used to make the central sliding shaft, the horizontal tail sliding shaft, and the rotation shaft, and plastic modules are used as the weight modules to reduce the overall mass. Using foam, carbon fiber, and plastic as the main materials and further optimizing the manufacturing steps have greatly reduced the subsequent manufacturing difficulty.

[0019] 4. Enhance the participation of students and teenagers in the classroom and science popularization activities, and provide more professional practice opportunities for students. The aerospace major is a highly comprehensive discipline integrating theory and practice. While explaining and popularizing theoretical knowledge, the dynamic demonstration device of the present invention can further cultivate students' ability to use relevant professional knowledge to solve practical problems. The present invention combines professional theoretical knowledge with practical application requirements to design a smart teaching demonstration tool, which can well provide a practical opportunity for students to apply what they have learned in courses such as Introduction to Aerospace, Introduction to Aerospace Engineering, Aerodynamics, and Flight Mechanics, enabling students to better understand the professional knowledge learned in class, while enhancing their practical ability, giving students more practical opportunities while participating in the classroom, and simultaneously enhancing the interest and enthusiasm of teenagers in exploring scientific knowledge in social aerospace science popularization activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a layout schematic diagram of a longitudinal static stability low-speed dynamic demonstration device for an aircraft of the present invention;

[0021] Figure 2 It is an internal schematic diagram of a longitudinal static stability low-speed dynamic demonstration device for an aircraft of the present invention;

[0022] Figure 3 It is a schematic diagram of the rearward movement of the small horizontal tail of a longitudinal static stability low-speed dynamic demonstration device for an aircraft of the present invention;

[0023] Figure 4 It is a schematic diagram of the forward movement of the large horizontal tail at the tail of a longitudinal static stability low-speed dynamic demonstration device for an aircraft of the present invention;

[0024] Figure 5 It is a schematic diagram of the rearward movement of the large horizontal tail at the tail of a longitudinal static stability low-speed dynamic demonstration device for an aircraft of the present invention;

[0025] The descriptions of the serial numbers in the figure are as follows:

[0026] 1 - Flat base

[0027] 2 - Inclined strut

[0028] 3 - Vertical strut

[0029] 4 - Support crossbeam

[0030] 5 - Rotating connection support

[0031] 6 - Uniform wind field

[0032] 7 - Nose

[0033] 8 - Fuselage

[0034] 9 - Tail

[0035] 10 - Wing

[0036] 11 - Small horizontal stabilizer

[0037] 12 - Rotating shaft of horizontal stabilizer

[0038] 13 - Sliding shaft of horizontal stabilizer

[0039] 14 - Large horizontal stabilizer

[0040] 15 - Central sliding shaft

[0041] 16 - Weight module

[0042] 17 - Engine

[0043] 18 - Vertical stabilizer Detailed implementation manners

[0044] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will elaborate on each implementation manner of the present invention in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in each implementation manner of the present invention, many technical details are presented for the readers to better understand the present invention. However, even without these technical details and various changes and modifications based on the following implementation manners, the technical solutions claimed by the present invention can still be achieved.

[0045] The present invention is an aircraft longitudinal static stability low - speed dynamic demonstration device. As shown in Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , it includes a flat base 1, inclined struts 2, vertical struts 3, support crossbeams 4, rotary connection supports 5, uniform wind field 6, nose 7, fuselage 8, tail 9, wing 10, small horizontal stabilizer 11, rotating shaft of horizontal stabilizer 12, sliding shaft of horizontal stabilizer 13, large horizontal stabilizer 14, central sliding shaft 15, weight module 16, and engine 17.

[0046] The flat base 1 is a wooden flat plate with dimensions of 400mm × 300mm × 40mm; the inclined struts 2, vertical struts 3, and support crossbeams 4 are all stainless - steel cylinders with a diameter of 3mm. The length of the vertical strut 3 is 400mm, the length of the inclined strut 2 is 600mm, and the length of the support crossbeam 4 is 300mm. The vertical strut 3 is inserted into a small hole at the center position 10mm away from the edge of the wooden board on one side of the flat base 1 for fixation; the inclined strut 2 is inserted into the two small holes at both ends 10mm away from the edge of the wooden board on the same side of the flat base 1, and the top is connected (such as welded) to the top of the vertical strut 3 to form an integral body; the support crossbeam 4 is connected (such as welded) to the top of the vertical strut 3 to form an integral body.

[0047] The nose 7, fuselage 8, tail 9, wings 10, small horizontal stabilizer 11, large horizontal stabilizer 14, and engine 17 are all made of foam material; the nose 7 is connected to the front end of the fuselage 8 (such as by glue) to form an integral body; the wings 10 are connected to both sides of the fuselage 8 (such as by glue) to form an integral body; the engines 17 are respectively connected to the lower sides of both wings 10 (such as by glue) to form an integral body; the tail 9 is connected to the rear end of the fuselage 8 (such as by glue) to form an integral body; the large horizontal stabilizer 14 is connected to the rear end of the tail 9 (such as by glue) to form an integral body.

[0048] The horizontal stabilizer rotating shaft 12, horizontal stabilizer sliding shaft 13, and central sliding shaft 15 are all carbon rods with a diameter of 3 mm. The length of the horizontal stabilizer rotating shaft 12 is 60 mm, the length of the central sliding shaft 15 is 350 mm, and the length of the horizontal stabilizer sliding shaft 13 is 550 mm; the weight module 16 is made of stainless steel and has a size of 30 mm × 30 mm × 30 mm; the central sliding shaft 15 passes through the small hole in the center of the weight module 16 and is inserted and fixed at the central position inside the fuselage 8, enabling the weight module 16 to move back and forth inside the fuselage 8; the horizontal stabilizer sliding shaft 13 is inserted and fixed at the central position inside the fuselage 8; the horizontal stabilizer rotating shaft 12 is inserted and connected through a prefabricated square through-hole at the leading edge of the large horizontal stabilizer 14, and the center is connected to the horizontal stabilizer sliding shaft 13, so that the horizontal stabilizer rotating shaft 12 together with the large horizontal stabilizer 14 can be on the horizontal stabilizer sliding shaft 13.

[0049] The specific operation steps of a longitudinal static stability low-speed dynamic demonstration device for an aircraft according to the present invention are as follows:

[0050] Step 1: Assemble and connect the flat base 1, inclined strut 2, vertical strut 3, and support crossbeam 4 according to the design and experimental requirements to form the connection support device of the device.

[0051] Step 2: Rotate the connecting support 5 through the support crossbeam 4, and the model aircraft achieves longitudinal static stability.

[0052] Step 3: Place the uniform wind field 6 below the nose 7, pointing along the front and rear direction of the fuselage towards the nose 7, and turn on the uniform wind field 6, then the model aircraft is longitudinally statically unstable.

[0053] Step 4: Adjust the horizontal stabilizer rotating shaft 12 to increase or decrease the angle of attack of the large horizontal stabilizer 14, observe the attitude characteristics of the model aircraft, and make the model aircraft achieve longitudinal static stability again.

[0054] Step 5: Adjust the horizontal stabilizer rotating shaft 12 to the initial state, the model aircraft is longitudinally statically unstable, move the weight module 16 on the central sliding shaft 15 to move the center of gravity of the model aircraft forward or backward, observe the attitude characteristics of the model aircraft, and make the model aircraft achieve longitudinal static stability again.

[0055] Step 6: Adjust the weight module 16 on the central sliding shaft 15 to its initial state. The model aircraft is longitudinally statically unstable. Move the large horizontal tail 14 forward and backward through the horizontal tail sliding shaft 13, and observe the attitude characteristics of the model aircraft to make the model aircraft achieve longitudinal static stability again.

[0056] Step 7: Move the large horizontal tail 14 to its initial position. The model aircraft is longitudinally statically unstable again. Replace the large horizontal tail 14 with the small horizontal tail 11 through the horizontal tail rotating shaft 12, and move the small horizontal tail 11 forward and backward through the horizontal tail sliding shaft 13, and observe the attitude characteristics of the model aircraft to make the model aircraft achieve longitudinal static stability again.

[0057] Step 8: Adjust the horizontal tail rotating shaft 12 to increase or decrease the angle of attack of the small horizontal tail 11. Synchronously move the small horizontal tail 11 forward and backward through the horizontal tail sliding shaft 13, and observe the attitude characteristics of the model aircraft to test the variation law and response speed of the longitudinal static stability of the model aircraft.

Claims

1. An aircraft longitudinal static stability low-speed dynamic demonstration device, comprising: Aircraft model, comprising: nose, fuselage, tail, wings, small horizontal stabilizer or large horizontal stabilizer, horizontal stabilizer rotating shaft, horizontal stabilizer sliding shaft, central sliding shaft, weight module, engine, vertical stabilizer; characterized in that: The nose, fuselage and tail are combined into a cavity with a hollow interior. The small horizontal stabilizer or large horizontal stabilizer is connected to the horizontal stabilizer rotating shaft and is located on both sides of the tail of the fuselage. The horizontal stabilizer sliding shaft and the central sliding shaft are respectively inserted into the interior of the fuselage and fixed to the internal structure of the fuselage. According to the demonstration needs, the horizontal stabilizer rotating shaft is respectively connected to the small horizontal stabilizer or large horizontal stabilizer as a whole. The small horizontal stabilizer or large horizontal stabilizer is directly inserted through the horizontal stabilizer rotating shaft from both sides. The center of the horizontal stabilizer rotating shaft is connected to the horizontal stabilizer sliding shaft, and the center of the horizontal stabilizer rotating shaft moves back and forth along the horizontal stabilizer sliding shaft. The weight module is connected to the central sliding shaft and slides back and forth along the central sliding shaft. The shell of the tail is a flexible rubber soft structure, and the shell is divided into upper and lower parts and separated from the middle gap. The horizontal stabilizer rotating shaft drives the small horizontal stabilizer or large horizontal stabilizer to move back and forth along the horizontal stabilizer sliding shaft. The small horizontal stabilizer or large horizontal stabilizer can simultaneously deflect upward or downward around the horizontal stabilizer rotating shaft, and the shell of the tail automatically deforms adaptively with the movement of the horizontal stabilizer rotating shaft; Connecting and supporting device for supporting and fixing the aircraft model; the connecting and supporting device includes a flat base, inclined struts, vertical struts, support crossbeam and rotary connecting support. A vertical strut is fixedly installed at the center on one side of the flat base, and inclined struts are fixedly installed at both ends on the same side. The support crossbeam is connected to the top of the vertical strut; the rotary connecting support is connected above the axis where the center of gravity of the fuselage is located; Uniform wind field device for providing a uniform wind field for the aircraft model; The nose, fuselage, tail, wings, small horizontal stabilizer or large horizontal stabilizer, and engine are all made of foam material. The nose is connected to the front end of the fuselage as a whole; the wings are connected to both sides of the fuselage as a whole; the engines are respectively connected to the lower sides of both wings as a whole; the tail is connected to the rear end of the fuselage as a whole. The leading edge of the small horizontal stabilizer or large horizontal stabilizer is inserted into the horizontal stabilizer rotating shaft and moves synchronously with the horizontal stabilizer rotating shaft. The small horizontal stabilizer or large horizontal stabilizer can simultaneously deflect upward or downward around the horizontal stabilizer rotating shaft.

2. The longitudinal static stability low-speed dynamic demonstration device for an aircraft according to claim 1, wherein: The inclined struts, vertical struts and support crossbeam on the flat base are all made of stainless steel.

3. The longitudinal static stability low-speed dynamic demonstration device for an aircraft according to claim 1, wherein: The vertical strut is inserted into the small hole on the flat base for fixation; the inclined strut is inserted into the small hole on the flat base, and the top is connected to the top of the vertical strut as a whole; the support crossbeam is connected to the top of the vertical strut as a whole.

4. An aircraft longitudinal static stability low-speed dynamic demonstration device according to claim 1, characterized in that: The horizontal stabilizer rotating shaft, horizontal stabilizer sliding shaft and central sliding shaft are all made of carbon fiber material with a square cross-section.

5. A method for operating the device according to any one of claims 1-4, comprising the following steps: Step one: Assemble and connect the flat base, inclined struts, vertical struts and support crossbeam according to the design and experimental requirements to form the connecting and supporting device of the device; Step two: The rotary connecting support passes through the support crossbeam, and the model aircraft achieves longitudinal static stability; Step 3: Place the uniform wind field below the nose of the aircraft, pointing along the longitudinal direction of the fuselage towards the nose, turn on the uniform wind field, and the model aircraft is longitudinally statically unstable. Step 4: Adjust the rotation axis of the horizontal tail, increase or decrease the angle of attack of the large horizontal tail, observe the attitude characteristics of the model aircraft, and make the model aircraft longitudinally statically stable again. Step 5: Adjust the rotation axis of the horizontal tail to the initial state, the model aircraft is longitudinally statically unstable, move the weight module on the center sliding axis to move the center of gravity of the model aircraft forward or backward, observe the attitude characteristics of the model aircraft, and make the model aircraft longitudinally statically stable again. Step 6: Adjust the weight module on the center sliding axis to the initial state, the model aircraft is longitudinally statically unstable, move the forward and backward position of the large horizontal tail through the horizontal tail sliding axis, observe the attitude characteristics of the model aircraft, and make the model aircraft longitudinally statically stable again.

6. The method according to claim 5, wherein: This method further includes: Step 7: Move the large horizontal tail to the initial position, the model aircraft is longitudinally statically unstable again, replace the large horizontal tail with a small horizontal tail through the horizontal tail rotation axis, and move the forward and backward position of the small horizontal tail through the horizontal tail sliding axis, observe the attitude characteristics of the model aircraft, and make the model aircraft longitudinally statically stable again. Step 8: Adjust the rotation axis of the rotating horizontal tail, increase or decrease the angle of attack of the small horizontal tail, and simultaneously move the forward and backward position of the small horizontal tail through the horizontal tail sliding axis, observe the attitude characteristics of the model aircraft, and test the variation law and response speed of the longitudinal static stability of the model aircraft.

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