CN109229369B - Novel torsion flapping wing structure and flapping wing torsion method - Google Patents
Novel torsion flapping wing structure and flapping wing torsion method Download PDFInfo
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- CN109229369B CN109229369B CN201811235861.2A CN201811235861A CN109229369B CN 109229369 B CN109229369 B CN 109229369B CN 201811235861 A CN201811235861 A CN 201811235861A CN 109229369 B CN109229369 B CN 109229369B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C33/00—Ornithopters
- B64C33/02—Wings; Actuating mechanisms therefor
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Abstract
The novel torsion flapping wing structure at least comprises a wing, a pipeline and a pump, wherein the root of the wing is a flapping wing shaft, the wing performs flapping wing vibration around the flapping wing shaft, the pipeline is positioned inside the wing, the pipeline comprises an inflow section, a connecting section and an outflow section, the pump is communicated with the pipeline, and the pump enables fluid to circulate in the pipeline. The novel torsion flapping wing structure provided by the application is simple and efficient to operate, frequency is automatically matched, and the effect on the large-aspect-ratio wing is obvious.
Description
Technical Field
The application relates to the field of bionic aircrafts, in particular to a torsion flapping wing structure and a flapping wing torsion method.
Background
An insect flapping wing aircraft belongs to a bionic aircraft. Insects fly through the flapping wings, generating both lift and thrust. The flapping wings move like a propeller, and the wings perform periodical flapping movement and spanwise torsion. By twisting, it is ensured that each cross section maintains approximately the same angle of attack as the incoming flow, thereby improving aerodynamic performance.
In the prior art, an active torsion mechanism is adopted for the torsion flapping wing, and the method needs an additional torsion mechanism and energy input, so that the complexity and the burden of the wing are increased; the torsion mechanism is controlled from the base of the wing, and for the whole wing, especially the wing with a large aspect ratio, the remote control efficiency of the wing is weak and the control efficiency is poor; furthermore, for independent panning and twisting, inputs are required to control their frequencies individually, increasing consumption.
Disclosure of Invention
Aiming at the defects of the existing torsion flapping wing structure and the control method thereof, the application provides a novel torsion flapping wing structure and a flapping wing torsion method. The technical scheme provided by the application can overcome the defects existing in the prior art, and widens the research thought of the insect ornithopter. In particular, the innovation of the present application focuses on the following four aspects: the novel twistable flapping wing structure provided by the application does not need an additional control module to match the twisting frequency with the flapping wing frequency, does not need an additional module to generate twisting and energy input, simplifies the structure of the twistable flapping wing, and is a high-efficiency twistable flapping wing structure and a flapping wing twisting method; according to the torsion flapping wing structure and the flapping wing torsion method, torque is generated at each position of the wing in the unfolding direction, and the torsion of the whole wing can be controlled at the same time; the wing with higher aspect ratio can be well controlled; in addition, the torsion frequency is automatically matched with the flapping wing frequency, so that the method accords with the motion rule and does not need additional control.
The first aspect of the application provides a novel torsion flapping wing structure, which at least comprises wings, a pipeline and a pump;
the root of the wing is a flapping wing shaft, and the wing swings around the flapping wing shaft;
the pipeline is positioned in the wing;
the pipeline comprises an inflow section, a connecting section and an outflow section;
the pump communicates with the conduit and circulates fluid in the conduit.
In some embodiments, the ducts are disposed spanwise within the wing.
In some embodiments, the inflow segment is located at the leading edge of the wing.
In some embodiments, the outflow section is located at the trailing edge of the wing.
In a second aspect the application provides a method of twisting a ornithopter using a twistable ornithopter structure comprising at least a wing, a conduit, a pump,
the root of the wing is a flapping wing shaft, the wing swings around the flapping wing shaft,
the tubing is positioned within the wing interior,
the pipeline comprises an inflow section, a connecting section and an outflow section,
the pump is in communication with the conduit, the pump circulating fluid in the conduit.
In some embodiments, the ducts are disposed spanwise within the wing.
In some embodiments, the inflow segment is located at the leading edge of the wing.
In some embodiments, the outflow section is located at the trailing edge of the wing.
In some embodiments, the pump is turned on to circulate the fluid in the conduit.
In some embodiments, the torsion frequency is automatically matched to the flapping frequency.
The beneficial effects of the application are as follows:
1. the novel torsion flapping wing structure and the flapping wing torsion method provided by the application do not need an additional control module to match torsion frequency and flapping wing frequency, do not need an additional module to generate torsion and energy input, simplify the structure of the torsion flapping wing, and are high-efficiency torsion flapping wing structure and flapping wing torsion method.
2. The torsion flapping wing structure and the flapping wing torsion method provided by the application can generate torque at each position of the wing in the unfolding direction, and can control the simultaneous torsion of the whole wing.
3. The novel torsion flapping wing structure and the flapping wing torsion method provided by the application can be used for better controlling the wings with higher aspect ratio.
4. The torsion frequency is automatically matched with the flapping wing frequency, accords with the motion rule, and does not need additional control.
Drawings
FIG. 1 is a schematic illustration of a twistable flapping wing structure provided by the application;
FIG. 2 is a schematic illustration of the force exerted by the fluid in the tubing in the ornithopter;
FIG. 3 is a schematic view of the stressed condition of a wing;
FIG. 4 is a graphical representation of the torque and translational torque experienced by a wing over time;
FIG. 5 is a test result of an embodiment of the present application;
FIG. 6 is a test result of an embodiment of the present application;
the figures are each marked as follows, 1 being a wing, 2 being an inflow section, 3 being an outflow section, 4 being a connecting section, 5 being a pump, 6 being a flapping wing shaft, and 7 being a pipe.
Detailed Description
For the purposes of the following detailed description, it is to be understood that the application may assume various alternative variations and step sequences, except where expressly specified to the contrary. Furthermore, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present application. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
Furthermore, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all subranges between (and including) the minimum value of 1 and the maximum value of 10, i.e., having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.
In a first aspect, as shown in fig. 1, the present application provides a novel twistable flapping wing construction, comprising at least a wing 1, a duct 7, a pump 5,
the root of the wing is a flapping wing shaft 6, the wing swings around the flapping wing shaft,
the tubing is positioned within the wing interior,
the pipe comprises an inflow section 2, a connecting section 4 and an outflow section 3,
the pump communicates with the conduit and circulates fluid in the conduit.
In some embodiments, the ducts are disposed spanwise within the wing.
In some embodiments, the inflow segment is located at the leading edge of the wing.
In some embodiments, the outflow section is located at the trailing edge of the wing.
The fluid sequentially passes through the inflow section, the connecting section and the outflow section in the pipeline positioned inside the wing. The fluid may be a liquid or a gas.
In a second aspect the application provides a method of twisting a ornithopter using a twistable ornithopter structure comprising at least a wing, a conduit, a pump,
the root of the wing is a flapping wing shaft, the wing swings around the flapping wing shaft,
the tubing is positioned within the wing interior,
the pipeline comprises an inflow section, a connecting section and an outflow section,
the pump communicates with the conduit and circulates fluid in the conduit.
In some embodiments, the ducts are disposed spanwise within the wing.
In some embodiments, the inflow segment is located at the leading edge of the wing.
In some embodiments, the outflow section is located at the trailing edge of the wing.
In some embodiments, the pump is turned on to circulate the fluid in the conduit.
In some embodiments, the torsion frequency is automatically matched to the flapping frequency.
The inventor has long studied and found that the flapping motion of the wing is periodic fixed axis rotation, and the flow velocity directions of the fluid in the inflow section and the outflow section of the pipeline are opposite, so that the acting directions of the fluid generated by the pipeline are opposite, and the direction is respectively vertical to the inward direction and the outward direction of the wing surface. The two are equal in size and opposite in direction, form moment and generate torsion on the wing.
The inventors of the present application believed that the wings vibrate reciprocally about the flapping axis during the flapping process at an angle that satisfies the simple harmonic motion, i.eWhere f is the flapping frequency and Φ is the flapping amplitude.
Then the angular velocity is
When fluid enters the inflow section of the duct at a flow velocity v, it flows out of the outflow section of the duct through the connecting section, completing a cycle in the plane of the wing. The inventors have unexpectedly found in the study that the inner wall of the pipe is subjected to an additional force, as shown in fig. 2, and the detailed analysis is as follows:
(1) When the diameters of the inflow section and the outflow section of the pipeline are the same, the flow rates are v, and the mass delta m of the fluid unit in the pipeline is subjected to a force perpendicular to the pipeline:
the direction of which can be determined by the right-hand spiral rule, perpendicular to the flow velocity v. The fluid cells exert the same force on the pipe wall due to the constraint of the pipe wall.
δF c Distributed in the form of linear loads along the inflow and outflow sections perpendicular to the airfoil as shown in fig. 3. Due to delta F c The forces acting on the inflow and outflow sections are equally and oppositely directed, depending on the direction of the fluid velocity.
The wings twist under the same and opposite line loads. Wherein the torque applied to the wing in the unit length of the spanwise direction is as follows
δM＝δF c ×r 1 +δF c ×r 2
r 1 And r 2 The displacement of the inflow and outflow sections, respectively, from the torsion axis, r, due to symmetry 1 ＝r 2 The torsion shaft is positioned at the middle position of the two pipelines.
When the wings flutter upward, the fluid in the inflow section of the pipeline generates a downward force perpendicular to the plane of the wings on the pipe wall when the fluid is forced to accept the vertical movement of the pipe, so that the flutter upward of the wings is hindered, and the fluid in the outflow section generates an upward force perpendicular to the plane of the wings on the pipe wall, so that the flutter upward of the wings is promoted. In this way, the wing is twisted by the combination of these two forces. Also, when the wing flutters downward, torque in the opposite direction is generated and the wing twists in the opposite direction.
According to the inventors' analysis, during periodic flapping, the fluid in the tube produces a periodic torque action on the wing, causing it to undergo simultaneous flat flapping and simultaneous torsional movement at the same frequency.
(2) When the pipe diameters of the inflow section and the outflow section are different, the flow rates can be equal, namelyDetermining velocity v 1 And v 2 Wherein d is 1 And d 2 The diameters of the inflow pipe and the outflow pipe are respectively; then from F 1 ×r 1 ＝F 2 ×r 2 The position of the torsion axis is determined, and other analysis procedures are the same as (1).
Since torque generation relies on unidirectional flow of fluid and wing-to-wing flapping motion, the frequency of torque naturally depends on the flapping frequency, without additional settings, and is specifically analyzed as follows:
for flapping-wing movementsThe plane flapping moment can be written as->Wherein->Is a constant; from the above calculation, it can be seen that the torque on the wing can be written as +.>Wherein->Is a constant. In the novel torsion flapping wing structure and the flapping wing torsion method provided by the application, the torque and the flapping have the same frequency, and are f, as shown in fig. 4.
In the flapping wing process, the torque generated by the application is changed according to the simple harmonic motion rule, and the maximum torque is obtained at the position with the maximum angular velocity; the minimum torque is almost zero at the time of upper and lower flutter transition. This law of variation in torque is consistent with the torsion required for the actual flight of the insect and the flight of the ornithopter.
Example 1
The novel torsion flapping wing structure comprises a wing, a pipeline and a pump, wherein the root of the wing is a flapping wing shaft, the wing performs flapping wing vibration around the flapping wing shaft, the pipeline is positioned inside the wing, the pipeline comprises an inflow section, a connecting section and an outflow section, the pump is communicated with the pipeline, and the pump enables fluid to circulate in the pipeline.
The ducts are arranged spanwise inside the wing.
The inflow section is located at the leading edge of the wing.
The outflow section is located at the trailing edge of the wing.
Example 2
A method for twisting the flapping wings includes such steps as providing a torsion flapping wing structure consisting of wings, pipeline, and pump for circulating the fluid in said pipeline, and arranging the pipeline in the pipeline.
The ducts are arranged spanwise inside the wing.
The inflow section is located at the leading edge of the wing.
The outflow section is located at the trailing edge of the wing. The torsion frequency is automatically matched with the flapping wing frequency.
The pump is turned on to circulate the fluid in the pipe, thereby realizing torsion in the flapping wing process.
Evaluation test 1
Establishing a wing model by adopting finite element software Abaqus, wherein the wing thickness is 0.5mm; limiting the frequency of the flapping wing to 60Hz and the amplitude to 60 degrees; a spread length of 10cm, a chord length of 5cm and an aspect ratio of 2/1; the flow rate is 1cm/s; the diameter of the pipeline is 0.6cm; the fluid is water with the density of 1g/cm 3 . The elastic modulus is 3GPa, and the Poisson ratio is 0.25; the torque M calculated above was applied to the model to obtain wing deformation results, with the maximum twist angle shown in FIG. 5.
Evaluation test II
Establishing a wing model by adopting finite element software Abaqus, wherein the wing thickness is 0.5mm; limiting the frequency of the flapping wing to 45Hz and the amplitude to 60 degrees; the expansion length is 24cm, the chord length is 6cm, and the aspect ratio is 4/1; the flow rate is 5cm/s; the diameter of the pipeline is 1cm; the fluid is water with the density of 1g/cm 3 . The elastic modulus is 2.8GPa, and the Poisson ratio is 0.3; the torque M calculated above was applied to the model to yield wing deformation results, with the maximum twist angle shown in FIG. 6.
The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the application and does not pose a limitation on the scope of the application unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the application.
Preferred embodiments of this application are described herein, including the best mode known to the inventors for carrying out the application. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the application to be practiced otherwise than as specifically described herein. Accordingly, this application includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the application unless otherwise indicated herein or otherwise clearly contradicted by context.
Claims (8)
1. A novel torsion flapping wing structure is characterized in that,
at least comprises a wing, a pipeline and a pump,
the root of the wing is a flapping wing shaft, the wing swings around the flapping wing shaft,
the tubing is positioned within the wing interior,
the pipeline comprises an inflow section, a connecting section and an outflow section,
the pump is communicated with the pipeline, and the pump circulates fluid in the pipeline;
the ducts are arranged spanwise inside the wing.
2. A novel twistable flapping wing structure according to claim 1, wherein,
the inflow section is located at the leading edge of the wing.
3. A novel twistable flapping wing structure according to claim 1, wherein,
the outflow section is located at the trailing edge of the wing.
4. A flapping wing torsion method is characterized in that,
a torsion flapping wing structure is adopted, the torsion flapping wing structure at least comprises a wing, a pipeline and a pump, the root of the wing is a flapping wing shaft, the wing swings around the flapping wing shaft,
the tubing is positioned within the wing interior,
the pipeline comprises an inflow section, a connecting section and an outflow section,
the pump is communicated with the pipeline, and the pump circulates fluid in the pipeline;
the ducts are arranged spanwise inside the wing.
5. A method of twisting a ornithopter of claim 4,
the inflow section is located at the leading edge of the wing.
6. A method of twisting a ornithopter of claim 4,
the outflow section is located at the trailing edge of the wing.
7. A method of twisting a ornithopter of claim 4,
the pump is turned on to circulate the fluid in the pipe.
8. A method of twisting a ornithopter of claim 5,
the torsion frequency is automatically matched with the flapping wing frequency.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201811235861.2A CN109229369B (en) | 2018-10-24 | 2018-10-24 | Novel torsion flapping wing structure and flapping wing torsion method |
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| CN201811235861.2A CN109229369B (en) | 2018-10-24 | 2018-10-24 | Novel torsion flapping wing structure and flapping wing torsion method |
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| CN109229369B true CN109229369B (en) | 2023-09-01 |
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| JP2013252756A (en) * | 2012-06-06 | 2013-12-19 | Aisin Engineering Kk | Center-of-gravity moving device for flying object |
| CN104554721A (en) * | 2015-02-08 | 2015-04-29 | 吉林大学 | Flapping wing capable of automatically folding and unfolding for flapping wing type micro aerial vehicle |
| CN104828246A (en) * | 2015-05-06 | 2015-08-12 | 李维农 | Scheme for improving efficiency of flapping-wing aircraft |
| WO2016177336A1 (en) * | 2015-05-06 | 2016-11-10 | 李维农 | Flapping wing machine and solution for improving efficiency of flapping wing aircraft |
| CN209382269U (en) * | 2018-10-24 | 2019-09-13 | 上海海事大学 | One kind is novel to reverse flapping wing structure |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013252756A (en) * | 2012-06-06 | 2013-12-19 | Aisin Engineering Kk | Center-of-gravity moving device for flying object |
| CN104554721A (en) * | 2015-02-08 | 2015-04-29 | 吉林大学 | Flapping wing capable of automatically folding and unfolding for flapping wing type micro aerial vehicle |
| CN104828246A (en) * | 2015-05-06 | 2015-08-12 | 李维农 | Scheme for improving efficiency of flapping-wing aircraft |
| WO2016177336A1 (en) * | 2015-05-06 | 2016-11-10 | 李维农 | Flapping wing machine and solution for improving efficiency of flapping wing aircraft |
| CN209382269U (en) * | 2018-10-24 | 2019-09-13 | 上海海事大学 | One kind is novel to reverse flapping wing structure |
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