Paddle, propeller, power module and aircraft

Abstract

The embodiment of the utility model provides a blade, a propeller, a power module and an aircraft, the blade is applied to the aircraft, the blade comprises a front edge, the front edge comprises a protruding structure protruding outwards, the protruding structure is located at the end, relatively close to a blade tip of the blade, of the front edge, and the amplitude of the protruding structure is A; wherein the size of A meets the following relational expression that A is larger than or equal to 0.035 R and smaller than or equal to 0.15 R, R represents the distance from the rotating center of the blade to the blade tip, and the rotating center represents the position of the rotating axis of the blade when the blade is installed on a driver of the aircraft. According to the paddle provided by the embodiment of the invention, a structure beneficial to noise reduction is additionally arranged by redesigning the shape of the paddle, and the noise can be reduced without a mode of reducing the size or reducing the rotating speed. Thus, compared with a traditional noise reduction means for the paddle, the aerodynamic efficiency of the paddle is not reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft technology, in particular to a blade, a propeller, a power module and an aircraft. BACKGROUND

[0002] The aerodynamic noise of the blade of the aircraft caused by rotation has gradually been concerned by the industry. In order to reduce the noise caused by the rotation of the blade, in the related art, common measures such as reducing the rotation speed of the blade and reducing the size of the blade are used to reduce the noise.

[0003] However, the above-mentioned improvement measures will cause the output power of the blade to be smaller, and the aerodynamic performance of the blade will be seriously lost.

[0004] Therefore, it is urgent to redesign a blade that meets the low noise requirement while not significantly losing the aerodynamic performance, so as to adapt to the low noise use scene of the aircraft. CONTENT OF THE INVENTION

[0005] Therefore, in order to solve the problem that the existing blade causes the aerodynamic performance to be reduced when reducing the noise, the present application provides a blade, a propeller, a power module and an aircraft to solve the above-mentioned problem.

[0006] In a first aspect, an embodiment of the present application provides a blade, which is applied to an aircraft, and the blade comprises:

[0007] A leading edge, the leading edge comprises a convex structure protruding outward, the convex structure is located at one end of the leading edge relatively close to a blade tip of the blade, and the amplitude of the convex structure is A;

[0008] Wherein, the size of A satisfies the following relationship: 0.035R≤A≤0.15R, R represents the distance from the rotation center of the blade to the blade tip, and the rotation center represents the position of the rotation axis of the blade when the blade is installed on the drive of the aircraft.

[0009] The blade of the present application has the convex structure protruding outward at one end of the leading edge close to the blade tip, and the degree of protruding outward is reasonably set, so that the aerodynamic noise can be significantly reduced on the basis of considering the higher aerodynamic efficiency.

[0010] In a second aspect, an embodiment of the present application provides a blade, which is applied to an aircraft, and the blade comprises:

[0011] A leading edge, the leading edge comprises a convex structure protruding outward, the convex structure is located at one end of the leading edge relatively close to a blade tip of the blade, and the amplitude of the convex structure is A;

[0012] a trailing edge opposite to the leading edge, the trailing edge comprising a specific portion corresponding to the protruding structure, the specific portion being located at an end of the trailing edge relatively close to the blade tip of the blade;

[0013] wherein the flatness of the specific portion is greater than the flatness of the protruding structure.

[0014] The blade of the embodiment of the present application has the protruding structure outwardly protruding at the end of the leading edge of the blade close to the blade tip, and the flatness of the specific portion of the trailing edge corresponding to the protruding structure is greater than the flatness of the protruding structure, so that the aerodynamic noise can be significantly reduced on the basis of taking into account the relatively high aerodynamic efficiency.

[0015] In a third aspect, an embodiment of the present application provides a propeller, comprising:

[0016] a propeller hub; and the blade of the first aspect or the second aspect, a root of the blade being connected to the propeller hub.

[0017] In a fourth aspect, an embodiment of the present application provides a power module, comprising: the propeller of the third aspect; and a driver connected to the propeller, the driver being configured to drive the propeller to rotate.

[0018] In a fifth aspect, an embodiment of the present application provides an aircraft, comprising: the power module of the fourth aspect.

[0019] The propeller, the power module and the aircraft of the embodiment of the present application have at least the same advantages as the blade, which will not be described here.

[0020] The above description is only a summary of the technical solutions of the present application. In order to enable the technical means of the present application to be more clearly understood, and to be implemented according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative labor.

[0022] Figure 1 a perspective view of a blade with a leading edge having a protruding structure according to an embodiment of the present application is shown;

[0023] Figure 2The paddle of the propeller of the embodiment of the application is shown in the following figures. Figure 1 The top view of the paddle along the -Z direction is shown in the following figure.

[0024] Figure 3 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0025] Figure 4 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0026] Figure 5 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0027] Figure 6 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0028] Figure 7 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0029] Figure 8 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0030] Figure 9 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0031] Figure 10 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0032] Figure 11 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0033] Figure 12 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0034] Figure 13 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0035] Figure 14 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0036] Figure 15 The paddle of the propeller of the embodiment of the application is shown in the following figures. Figure 14 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0037] Figure 16 The paddle of the propeller of the embodiment of the application is shown in the following figures.

[0038] Figure 17 The noise reduction comparison of the propeller of the embodiment of the application and the conventional propeller in different configurations is shown Figure 16 The noise reduction comparison of the propeller of the embodiment of the application and the conventional propeller in different configurations is shown

[0039] Figure 18 The sound pressure level curve of the propeller of the embodiment of the application and the conventional propeller in different configurations is shown

[0040] Figure 19 The noise performance of the propeller of the embodiment of the application and the conventional propeller in different configurations on the whole aircraft is shown

[0041] Figure 20 The single-propeller noise performance of the propeller of the embodiment of the application and the conventional propeller in different configurations is shown

[0042] Figure 21 The single-propeller thrust performance of the propeller of the embodiment of the application and the conventional propeller in different configurations is shown

[0043] Figure 22 The single-propeller torque performance of the propeller of the embodiment of the application and the conventional propeller in different configurations is shown.

[0044] Explanation of reference signs:

[0045] Propeller-10, leading edge-101, trailing edge-102, convex structure-1011, specific part-1021, first leading edge part-101a, first trailing edge part-102a, first starting point-S1, first peak point-M1, first ending point-F1, first extension line-l1, first intersection point-G1, second starting point-S2, second peak point-M2, second ending point-F2, second extension line-l2, second intersection point-G2, blade root-10a, blade body-10b, blade tip-10c, first connecting segment-1011a, second connecting segment-1011b, third connecting segment-1021a, second connecting segment-1021b, first position point-D1, second position point-D2, third position point-D3. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some but not all of the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the application.

[0047] It should be appreciated that any reference to "one embodiment" or "an embodiment" throughout the application means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearance of the phrase "in one embodiment" or "in an embodiment" in various places throughout the specification is not necessarily referring to the same embodiment. Further, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Additionally, the words "substantially," "approximately," and the like can describe an amount that is acceptable at a reasonable level of accuracy.

[0048] The embodiment of the present application discloses a propeller 10 which can be used on an aircraft, the propeller 10 increases the structure beneficial to reduce noise by redesigning the shape, without reducing noise by reducing size or reducing speed.

[0049] The aircraft in the embodiment of the present application is classified according to whether there is a person in the cabin to drive, including unmanned aircraft and manned aircraft; classified according to the configuration, including rotary-wing aircraft (such as single-rotor or multi-rotor), rotary-wing and fixed-wing combined aircraft; classified according to the use, including aerial photography aircraft, plant protection aircraft, surveying and mapping aircraft, logistics aircraft, etc.

[0050] Specifically, Figure 1 The axial schematic diagram of the propeller 10 of the embodiment of the present application is given, in order to facilitate the description of the shape structure of the propeller 10, a relative coordinate system composed of mutually perpendicular X-axis, Y-axis and Z-axis is also set for the propeller 10 itself as shown in the figure, the Z-axis is the thickness direction of the propeller 10, and coincides with the rotation axis of the propeller 10 when the propeller 10 is installed on the driver of the aircraft, and the +Z direction points from the pressure surface to the suction surface. At this time, the rotation center O where the rotation axis is located is the coordinate origin. The X-axis is parallel to the chord line of the propeller 10, and the +X direction points from the leading edge 101 to the trailing edge 102. The Y-axis represents the radial direction of the propeller 10, and the +Y direction points from the rotation center O of the propeller 10 to the tip.

[0051] Among them, the tip refers to the farthest end corresponding to the rotation center O. In some configurations, the tip can be a certain end point; in other configurations, the tip can also be a certain end face.

[0052] Among them, R represents the radius of the propeller 10, and represents the distance from the rotation center O of the propeller 10 to the tip. Further, the distance is the distance between the vertical projection point of the tip in the Y direction and the rotation center O.

[0053] In some embodiments, for example, the value range of R is 10-20 mm, for example, R is 13 mm.

[0054] It should be noted that the relative coordinate system is used to represent the relative position relationship between the parts of the blade 10 itself, and does not represent the relative position relationship between the blade 10 and the installed aircraft.

[0055] As Figure 2 The schematic view of the blade 10 in the embodiment of the present application is shown in FIG. 1, which includes a leading edge 101 on one side of the rotating direction of the blade 10. The leading edge 101 includes a protruding structure 1011 that protrudes outward, that is, protrudes in a direction away from the physical structure of the blade 10, as shown in FIG. 2. Figure 2 The protruding structure 1011 protrudes in the rotating direction of the blade 10 (for example, the -X direction shown in the figure), as shown in FIG. 2. In combination with the schematic view shown in FIG. 3, along the Y direction shown in the figure, the protruding structure 1011 is closer to the blade tip of the blade 10 and further away from the rotating center O of the blade 10. Figure 2

[0056] The blade 10 in the embodiment of the present application, from the mechanism of gas dynamics, on the one hand, reduces the surface pressure fluctuation intensity (also known as sound source intensity) of the blade 10, and reduces the turbulence intensity; on the other hand, the protruding structure 1011 on one side of the leading edge 101 reduces the radial space correlation coefficient and the spanwise coherence of the leading edge 101; on the other hand, the interference effect between the sound sources is enhanced, and the destructive interference effect reduces the radiation efficiency of the noise. Therefore, the blade 10 with the protruding structure 1011 has lower noise. And compared with the conventional noise reduction method, it will not cause a significant decrease in aerodynamic performance.

[0057] It should be noted that the shape of the protruding structure 1011 and the distribution position on the leading edge 101 have an important influence on the noise reduction effect of the blade 10, which can at least affect the degree of reduction of the pressure pulse, the degree of phase interference effect of the pressure pulse, etc. Therefore, some key parameters of the protruding structure 1011 are introduced below.

[0058] In some embodiments, the height of the protruding structure 1011 protruding outward is defined as the amplitude, which is A. The greater A is, the higher the protruding height of the protruding structure 1011 is, the more obvious the sound source intensity is reduced, the phase interference of the sound wave is enhanced, and the noise reduction effect is better. However, when A increases to more than a certain preset value, the aerodynamic performance of the blade 10 will be significantly lost.

[0059] ​In some embodiments, the amplitude A satisfies the following condition: 0.035R≤A≤0.15R. When A is within the above range, the blade 10 not only satisfies the effect of low noise, but also does not significantly lose aerodynamic performance. For example, A can take a value of 0.035R, 0.045R, 0.05R, 0.06R, 0.07R, 0.08R, 0.09R, 0.1R or 0.15R, etc.

[0060] In some embodiments, the above A can be preferably designed as 0.073R.

[0061] In some embodiments, the ratio between the amplitude A and R of the convex structure 1011 of the blade 10 of different sizes can be different. For example, for a larger R, the ratio of A to R of the convex structure 1011 is smaller relative to a smaller R.

[0062] In addition, in an embodiment, as shown in Figure 2 in the Y direction, the convex structure 1011 is sequentially distributed with a first starting point S1, a first peak point M1 and a first ending point F1. The part of the leading edge 101 that initially protrudes outward is the first starting point S1 of the convex structure 1011, the highest part of the convex structure 1011 that protrudes outward is the first peak point M1, and the part of the convex structure 1011 that continues to fall to the leading edge 101 is the first ending point F1. The first starting point S1, the first peak point M1 and the first ending point F1 can continuously depict the outer shape of the convex structure 1011.

[0063] Alternatively, according to the above description of the key points for forming the convex structure 1011, the amplitude A can be further explained as follows. The part of the leading edge 101 that is outside the convex structure 1011 and close to the first starting point S1 is defined as the first leading edge portion 101a, and the extension line starting from the first leading edge portion 101a and passing through the first starting point S1 in the leading edge 101 is taken as the first extension line l1. The chord line passing through the first peak point M1 intersects the first extension line l1 to form a first intersection point G1, and the distance between the first peak point M1 and the first intersection point G1 is the aforementioned amplitude A.

[0064] Alternatively, in an embodiment, as shown in Figure 3 the convex structure 1011 does not necessarily have a sharp peak shape, and the part that protrudes outward can also be an approximately flat structure formed by a straight line or a curve. Accordingly, the amplitude A is the distance between the outermost point in the X direction of the flat structure and the intersection point formed by the chord line passing through the point and the first extension line.

[0065] Alternatively, in an embodiment, as shown in Figure 4As shown, along the radial direction of the blade 10 (i.e. the Y direction shown in the figure), from the rotation center O to the blade tip, the blade 10 comprises, in sequence, a blade root portion 10a, a blade body portion 10b, and a blade tip portion 10c. In combination Figure 4 It should be noted that the blade root portion 10a can be spaced apart from the rotation center O or can extend to the position of the rotation center O. The blade body portion 10b is a portion with a larger area in the middle of the blade 10. The blade tip portion 10c and the blade root portion 10a are respectively fixedly connected to the two sides of the blade body portion 10b, and are usually integrally formed. When the blade 10 is connected with the drive of the aircraft, the blade root portion 10a is close to the rotating shaft of the drive, and the blade tip portion 10c is at a position far away from the rotating shaft of the drive.

[0066] When the rotor aircraft performs complex flight maneuvers, the aerodynamic state of the blade will be more complex, for example, when the rotor aircraft flies forward, the flow field can simultaneously appear rotor blade tip transonic flow, and blade root low-speed reverse flow, accompanied by dynamic stall, blade vortex interference and other complex aerodynamic phenomena.

[0067] Therefore, in an embodiment of the present application, in combination Figure 2 and Figure 4 As shown, in this blade 10, when the protruding structure 1011 is located at the blade tip portion 10a, it is closer to the blade tip, and it is easier to reduce the strength of the blade tip vortex, and the noise reduction effect is better.

[0068] Optionally, in an embodiment, as shown in Figure 4 The protruding structure 1011 comprises two parts along the radial direction of the blade 10, one part is a first connecting segment 1011a between a first starting point S1 and a first peak point M1, and the other part is a second connecting segment 1011b between the first peak point M1 and a first ending point F1.

[0069] Optionally, in an embodiment, as shown in Figure 4 The first connecting segment 1011a is on the left side of the first peak point M1 and is a portion of the protruding structure 1011 far away from the blade tip of the blade 10. The second connecting segment 1011b is on the right side of the first peak point M1 and is a portion of the protruding structure 1011 close to the blade tip of the blade 10.

[0070] Optionally, in an embodiment, as shown in Figure 4As shown, from the direction of the rotation center O to the blade tip, the leading edge 101 formed by the first connecting segment 1011a gradually moves away from the trailing edge 102, that is, the distance between the first connecting segment 1011a and the trailing edge 102 gradually increases, so that the first connecting segment 1011a has an upward trend, while the leading edge 101 formed by the second connecting segment 1011b gradually moves closer to the trailing edge 102, that is, the distance between the second connecting segment 1011b and the trailing edge 102 gradually decreases, so that the second connecting segment 1011b has a downward trend. Thus, the position where the first connecting segment 1011a and the second connecting segment 1011b intersect forms a first peak point M1 of the convex structure 1011.

[0071] It should be noted that the line segment shape of the first connecting segment 1011a and the second connecting segment 1011b can be a straight line or a curve. For any connecting segment in a curved shape, it can be a smooth curve or a waveform curve with multiple concave and convex fluctuations. The first connecting segment 1011a and the second connecting segment 1011b together form the convex structure 1011 which protrudes outward. The specific shape of the first connecting segment 1011a and the second connecting segment 1011b is not limited in the embodiments of the present application.

[0072] Optionally, in an embodiment, as shown in Figure 5 The distance between the first starting point S1 and the rotation center O is a distance parameter r1. Further, the distance is the distance between the intersection point of the chord line passing through the first starting point S1 and the Y-axis and the rotation center O. When r1 is larger, it indicates that the first starting point S1 is closer to the blade tip.

[0073] In some embodiments, r1 satisfies 0.65R≤r1≤0.8R. For example, r1 can take values of 0.65R, 0.7R, 0.73R, 0.75R, 0.78R or 0.8R, etc.

[0074] In some embodiments, preferably, r1 can be designed as 0.75R.

[0075] Optionally, in an embodiment, as shown in Figure 5 The distance between the first peak point M1 and the rotation center O is a distance parameter r2. Further, the distance is the distance between the intersection point of the chord line passing through the first peak point M1 and the Y-axis and the rotation center O.

[0076] In some embodiments, r2 satisfies 0.75R≤r2≤0.95R. For example, r2 can take values of 0.75R, 0.77R, 0.8R, 0.82R, 0.85R, 0.88R, 0.9R or 0.95R, etc.

[0077] In some embodiments, preferably, r2 can be designed as 0.85R. In some embodiments, the first connecting segment 1011a and the second connecting segment 1011b can be straight lines.

[0078] Optionally, in an embodiment, as shown in Figure 5 the distance parameter between the first starting point S1 and the first ending point F1 is d. Further, the distance is the width range of the convex structure 1011 along the radial direction.

[0079] In some embodiments, d satisfies 0.15R≤d≤0.35R. For example, d can take the value of 0.15R, 0.2R, 0.25R, 0.3R or 0.35R, etc.

[0080] In some embodiments, preferably, d can be designed as 0.25R.

[0081] Optionally, in an embodiment, as shown in Figure 2 the blade 10 of the present application further comprises a trailing edge 102 opposite to the leading edge 101, and the trailing edge 102 comprises a specific part 1021 corresponding to the convex structure 1011, which is located at one end of the trailing edge 102 relatively close to the blade tip of the blade 10. Further, the specific part 1021 represents the part of the trailing edge 102 from the first position point to the second position point, wherein the first position point represents the intersection point of the chord line where the first starting point S1 of the convex structure 1011 is located on the trailing edge 102, and the second position point represents the intersection point of the chord line where the first ending point F1 of the convex structure 1011 is located on the trailing edge 102.

[0082] In some embodiments, the flatness of the specific part 1021 is greater than the flatness of the convex structure 1011. For example, when at least one of the following conditions is satisfied, the flatness of the specific part 1021 can be considered to be greater than the flatness of the convex structure 1011: (1) the projection area formed by the specific part 1021 along the Z direction is smaller than the projection area of the convex structure 1011; (2) the specific part 1021 has an opening included angle greater than the included angle of the convex structure 1011; (3) the depth of the specific part 1021 is less than the height of the convex structure 1011.

[0083] Optionally, the specific part 1021 described above can be a concave structure recessed from the trailing edge 102 towards the leading edge 101.

[0084] Optionally, the specific part 1021 described above can also be a part of the trailing edge 102 which keeps a smooth transition with other parts.

[0085] The specific part 1021 of the trailing edge 102 part of the blade 10 helps to reduce the amplitude of the flap deformation of the blade 10, thereby stabilizing its aerodynamic performance.

[0086] Optionally, in an embodiment, as shown in Figure 6As shown, when the specific part 1021 at the position of the trailing edge 102 is a concave structure, on one hand, it can play a role in reducing weight and unloading, which is beneficial to reduce the amplitude of the flap 10 in the edgewise deformation, and on the other hand, it can increase the chord length at the convex structure 1011 while keeping the amplitude of the convex structure 1011 unchanged. The depth of the inward concave structure is defined as the amplitude, and the parameter is B. The sizes of B and A satisfy the following relationship: 0 < B < A. Thus, the concave structure can be more gentle than the convex structure 1011.

[0087] Optionally, in an embodiment, the larger the amplitude B is, the lighter the flap 10 is, the smaller the force is, and the smaller the edgewise deformation is. However, when B is too small, the chord length of the concave structure is reduced, the Reynolds number is reduced, and the aerodynamic performance is easily lost. Conversely, when B is large, the Reynolds number is increased, and the aerodynamic performance is more improved.

[0088] In some embodiments, the size of B in the embodiment of the application satisfies the following relationship: 0 < B ≤ 0.03R, which can reduce the edgewise deformation and also have higher aerodynamic performance. For example, B can be 0.01R, 0.02R or 0.03R.

[0089] In some embodiments, B can be preferably designed as 0.026R.

[0090] Optionally, in an embodiment, as shown in Figure 4 The concave structure in the embodiment of the application can also be located at the blade tip 10c, which is beneficial to reduce the weight of the blade tip 10c and reduce the influence of the edgewise deformation caused by the self weight of the blade tip 10c.

[0091] In addition, in an embodiment, as shown in Figure 6 In the Y direction, the second starting point S2, the second peak point M2 and the second ending point F2 are sequentially distributed, the part of the trailing edge 102 that is initially inwardly concave is the second starting point S2 of the concave structure, the vertex part of the inwardly concave concave structure is the second peak point M2, and the part of the trailing edge 102 that continues to extend is the second ending point F2. The second starting point S2, the second peak point M2 and the second ending point F2 can continuously depict the outline shape of the concave structure.

[0092] Optionally, according to the above description of the key points of forming the concave structure, the amplitude B can be further explained as follows. The part of the trailing edge 102 that is outside the concave structure and close to the second starting point S2 is defined as the first trailing edge part 102a, and the extension line starting from the first trailing edge part 102a and passing through the second starting point S2 in the trailing edge 102 is taken as the second extension line l2. The chord line passing through the second peak point M2 intersects with the second extension line l2 to form the second intersection point G2, and the distance between the second peak point M2 and the second intersection point G2 is the aforementioned amplitude B.

[0093] Optionally, in an embodiment, as shown in Figure 7 the aforementioned recessed structure comprises two parts along the radial direction of the blade 10, one part is a third connecting segment 1021a between the second starting point S2 and the second peak point M2, and the other part is a fourth connecting segment 1021b between the second peak point M2 and the second ending point F2.

[0094] Optionally, in an embodiment, as shown in Figure 7 the third connecting segment 1021a is on the left side of the second peak point M2, which is the part of the recessed structure far from the blade tip of the blade 10. The fourth connecting segment 1021b is on the right side of the second peak point M2, which is the part of the recessed structure close to the blade tip of the blade 10.

[0095] Optionally, in an embodiment, as shown in Figure 7 from the direction of the rotation center O to the blade tip, the trailing edge 102 formed by the third connecting segment 1021a gradually approaches the leading edge 101, that is, the distance between the third connecting segment 1021a and the leading edge 101 gradually decreases, so that the third connecting segment 1021a has an upward trend, while the trailing edge 102 formed by the fourth connecting segment 1021b gradually moves away from the leading edge 101, that is, the distance between the fourth connecting segment 1021b and the leading edge 101 gradually increases, so that the fourth connecting segment 1021b has a downward trend. Therefore, the position where the third connecting segment 1021a and the fourth connecting segment 1021b intersect forms the second peak point M2 of the recessed structure.

[0096] It should be noted that the line segment shape of the third connecting segment 1021a and the fourth connecting segment 1021b can be a straight line or a curve. For any connecting segment in the form of a curve, it can be a smooth curve or a waveform curve with multiple concave and convex fluctuations, and the third connecting segment 1021a and the fourth connecting segment 1021b together form a concave recessed structure. The specific shape of the third connecting segment 1021a and the fourth connecting segment 1021b is not limited in the embodiments of the present application.

[0097] Optionally, as shown in Figure 8 the part of the trailing edge 102 corresponding to the convex structure 1011 is continuously and gently arranged. Compared with the recessed structure, this part of the blade has a larger area and a larger lift, and has better aerodynamic performance.

[0098] Optionally, as shown in Figure 8 and in combination with the description of the foregoing embodiments, when a straight line or a curve with substantially the same slope at different positions is used to connect the second starting point S2 and the second ending point F2, a gently arranged part corresponding to the convex structure 1011 can be formed.

[0099] Optionally, as shown in Figure 8 In an embodiment, the paddle 10 further has a first position point D1 and a second position point D2. The first position point D1 represents the intersection point of the chord line where the first starting point S1 of the protruding structure 1011 is located on the trailing edge 102. The second position point D2 represents the intersection point of the chord line where the first ending point F1 of the protruding structure 1011 is located on the trailing edge 102. The portion of the trailing edge 102 between the first position point D1 and the second position point D2 represents the portion corresponding to the protruding structure 1011. At this time, the first position point D1 and the second position point D2 can be connected by a straight line or an approximately straight line.

[0100] Optionally, as shown in Figure 8 In an embodiment, the paddle 10 further has a third position point D3. The third position point D3 represents the intersection point of the chord line where the first peak point M1 of the protruding structure 1011 is located on the trailing edge 102. The extension line between the first position point D1 and the third position point D3 passes through the paddle tip. Thus, the paddle 10 with such a shape design can ensure that the portion of the trailing edge 102 corresponding to the protruding structure 1011 is continuously and gently arranged.

[0101] Optionally, in an embodiment, the paddle 10 is a paddle made of a lightweight material. For example, the paddle 10 can be made of any one of the following materials: a plastic material, a fiber material, an alloy material, and a fiber composite material. In the field of unmanned aerial vehicles, there are strict requirements for the self-weight of the aerial vehicle. The paddle 10 made of a lightweight material can help reduce the self-weight of the aerial vehicle and reduce the manufacturing cost of the paddle 10.

[0102] However, while reducing the weight, the paddle made of a lightweight material inevitably loses the structural strength of the paddle compared with the paddle made of a heavy material such as metal. In particular, the side of the paddle 10 close to the rotation center O is easily affected by a large rotation centrifugal force, and thus has a higher requirement for the structural strength. Based on this, the embodiment of the present application further strengthens the structural strength of the paddle 10 by the configuration design of the paddle 10 while reducing the weight.

[0103] Optionally, as shown in Figure 4As shown in the figure, in one embodiment, the blade 10 sequentially comprises a blade root portion 10a, a blade body portion 10b and a blade tip portion 10c. The blade root portion 10a of the blade 10 also has one of the following shape characteristics: (1) from the direction of the rotation center O to the blade tip, there is at least a region of the blade root portion 10a whose corresponding chord length gradually increases. Thus, both the ease of installation and the use of the gradually widened at least part of the blade root portion 10a to enhance the connection strength of the blade can be ensured; (2) from the direction of the rotation center O to the blade tip, the entire blade root portion 10a has a gradually increasing chord length, so that both the ease of installation and the use of the gradually widened blade root portion 10a to enhance the connection strength of the blade can be ensured. For example, the position point at which the chord length starts to increase is between 0.2R and 0.3R, for example, 0.246R.

[0104] Optionally, as shown in the figure, in one embodiment, the blade body portion 10b of the blade 10 also has one of the following shape characteristics: (1) from the direction of the rotation center O to the blade tip, there is at least a region of the blade body portion 10b whose corresponding chord length gradually decreases, so that both the weight of the blade and the smoothness of the airflow on the surface of the blade can be improved; (2) from the direction of the rotation center O to the blade tip, the entire blade body portion 10b has a gradually decreasing chord length, so that both the weight of the blade 10 and the smoothness of the airflow on the surface of the blade 10 can be improved. Figure 4 As shown in the figure, in one embodiment, the blade body portion 10b of the blade 10 also has one of the following shape characteristics: (1) from the direction of the rotation center O to the blade tip, there is at least a region of the blade body portion 10b whose corresponding chord length gradually decreases, so that both the weight of the blade and the smoothness of the airflow on the surface of the blade can be improved; (2) from the direction of the rotation center O to the blade tip, the entire blade body portion 10b has a gradually decreasing chord length, so that both the weight of the blade 10 and the smoothness of the airflow on the surface of the blade 10 can be improved.

[0105] Figure 2 As shown in the figure, in one embodiment, the blade body portion 10b of the blade 10 also has one of the following shape characteristics: (1) from the direction of the rotation center O to the blade tip, there is at least a region of the blade body portion 10b whose corresponding chord length gradually decreases, so that both the weight of the blade and the smoothness of the airflow on the surface of the blade can be improved; (2) from the direction of the rotation center O to the blade tip, the entire blade body portion 10b has a gradually decreasing chord length, so that both the weight of the blade 10 and the smoothness of the airflow on the surface of the blade 10 can be improved. Figure 8 As shown in the figure, in one embodiment, the blade body portion 10b of the blade 10 also has one of the following shape characteristics: (1) from the direction of the rotation center O to the blade tip, there is at least a region of the blade body portion 10b whose corresponding chord length gradually decreases, so that both the weight of the blade and the smoothness of the airflow on the surface of the blade can be improved; (2) from the direction of the rotation center O to the blade tip, the entire blade body portion 10b has a gradually decreasing chord length, so that both the weight of the blade 10 and the smoothness of the airflow on the surface of the blade 10 can be improved.

[0106] In a specific implementation, the specific portion 1021 can be a concave structure concave inward from the trailing edge 102 toward the leading edge 102, or can be a portion that smoothly transitions with other parts of the trailing edge 102.

[0107] As shown in the figure, in one embodiment, the blade body portion 10b of the blade 10 also has one of the following shape characteristics: (1) from the direction of the rotation center O to the blade tip, there is at least a region of the blade body portion 10b whose corresponding chord length gradually decreases, so that both the weight of the blade and the smoothness of the airflow on the surface of the blade can be improved; (2) from the direction of the rotation center O to the blade tip, the entire blade body portion 10b has a gradually decreasing chord length, so that both the weight of the blade 10 and the smoothness of the airflow on the surface of the blade 10 can be improved.

[0108] Figure 9 to Figure 11 ​​As shown in the illustration, this application also provides a propeller, which includes a propeller base 11 and the propeller blades 10 disclosed in the foregoing embodiments. The propeller base 11, also known as the propeller hub, is used to connect the propeller blades 10 to a corresponding driver. The propeller base 11 can be fixedly connected to the rotation shaft of the driver, and the root of the propeller blades 10 can be fixed to the propeller base 11 to maintain relative stillness and thus move synchronously. The root of the propeller blades 10 can also be hinged to the propeller base 11 to achieve folding and storage of the propeller blades 10.

[0109] Optionally, when the number of blades 10 is two or more, each blade 10 is connected to a blade holder 11, and all blades 10 are evenly spaced around the center of the blade holder 11, with the center of the blade holder 11 being the rotation center O. For example, Figure 10 The two blades 10 are arranged along the same straight line, and the included angle between the two blades 10 is 180°. Figure 11 The three blades 10 are evenly distributed at 120° around the center of the propeller base 11. At this time, the more evenly distributed blades 10 can provide smooth and sufficient lift, the propeller has better aerodynamic performance, and because each blade 10 has lower noise, the propeller also has better low noise performance.

[0110] like Figure 12 As shown in the illustration, this application also discloses a power module, which includes a propeller as described in the previous embodiment and a driver 12 for driving the propeller to rotate. The driver 12 in this power module can be an electric motor, a fuel engine, or a hydraulically driven device. The driver 12 can be mounted on the main body of the aircraft or on a support member (such as an arm or propeller blade protection device) extending from the main body of the aircraft. This power module using the aforementioned propeller also has lower noise, meeting the requirements for use in low-noise environments.

[0111] like Figure 13 As shown in the embodiments, this application also discloses an aircraft, which includes the power module described in the foregoing embodiments.

[0112] It will be apparent to those skilled in the art that any type of aircraft can be used without limitation, for example, the aircraft can be a small or large aircraft. The aircraft can be a manned aircraft or an unmanned aircraft. Specifically, the aircraft can include a rotorcraft or a fixed-wing-rotor hybrid aircraft, etc. Among them, the rotorcraft can be a single-rotor aircraft, a twin-rotor aircraft, a multi-rotor aircraft, etc. The aircraft can include but is not limited to manned aircraft, logistics aircraft, aerial photography aircraft, agricultural plant protection aircraft, industry rescue aircraft, or performance aircraft. The above is only an example, and the embodiments of the present application do not specifically limit the type of aircraft. The aircraft includes an unmanned aerial vehicle (UAV) and a manned aircraft, etc. The aircraft can be used for one or more tasks such as aerial photography, aerial reconnaissance, geographic mapping, transportation, agricultural action, performance, environmental monitoring, and security patrol.

[0113] The power module of the foregoing embodiments applied to the aircraft can reduce the working noise of the aircraft and expand the applicable scenarios of the aircraft.

[0114] As a specific application embodiment, in the application scenario of applying the high-efficiency low-noise propeller to the multi-rotor aircraft:

[0115] Most current multi-rotor unmanned aerial vehicles face the problem that the aerodynamic noise exceeds the index. The propeller noise is the main sound source of the unmanned aerial vehicle noise. With the noise index of some areas becoming more and more stringent year by year, the propeller blade noise reduction design requirement of the unmanned aerial vehicle is gradually improved. The current common noise reduction means is to reduce the speed of the propeller tip by reducing the speed and reducing the size, which will cause the motor temperature rise and the propeller aerodynamic efficiency to be reduced. In order to solve the problems of efficiency, speed and noise, the traditional noise reduction means is to reduce the speed of the propeller tip by reducing the speed and reducing the size, but these ways will lose the aerodynamic efficiency of the propeller and cause the motor temperature rise. The propeller is the load of the motor, and the speed reduction has certain negative effects: increasing the motor torque, reducing the motor efficiency, increasing the motor temperature rise, and finally causing the efficiency of the whole power system to be greatly reduced, affecting the flight performance and safety of the unmanned aerial vehicle.

[0116] Therefore, in order to solve the problems of efficiency, speed and noise at the same time, the main noise reduction mechanism of the embodiments of the present application is that the propeller well reduces the intensity of the pressure fluctuation on the surface of the propeller (also called the sound source intensity); the propeller reduces the correlation coefficient and coherence along the radial direction of the leading edge 101 due to the special convexity (such as the convex structure 1011 shown in the figure) of the wave crest (the conventional propeller is mostly flat); the propeller increases the interference between the sound sources, and the destructive interference effect reduces the radiation efficiency of the noise. Figure 1

[0117] ​The embodiment of the present application mainly relates to the design of a noise reduction blade Figure 1 The schematic convex structure 1011 is regarded as a wave crest, and the structure specifically comprises a wave crest position, a wave crest height, a wave starting position, a wave width and the like. Figure 1 to Figure 5 In the embodiment, a blade coordinate system is defined as a right-hand system, a Y axis is defined as a blade radial direction, a Z axis is defined as a blade thickness direction, and an X axis is defined as a blade chord length direction.

[0118] As shown in the schematic diagram, Figure 5 The distance between the wave crest starting point S1 of the blade and the rotation center O is defined as a wave starting point radius r1; the distance between the wave crest peak point M1 and the rotation center O is defined as a wave crest radius r2; the wave crest height of the blade is defined as a wave crest amplitude A; and the distance between the wave crest starting point S1 and the wave crest ending point F1 of the blade is defined as a wave crest width d.

[0119] The above parameters have the following characteristics and meet the following requirements:

[0120] The wave starting point radius r1: the wave starting position is different, and the corresponding wave crest shape is different. In the experimental verification, it is found that when the wave starting position is slightly behind (i.e., close to the blade tip), the wave shape is more full, and the noise reduction effect is better. In combination with the actual engineering needs, in the embodiment of the present application, r1=0.75, and the main interval of r1 is 0.65R≤r1≤0.8R.

[0121] The wave crest radius r2: the wave crest position affects the radial distribution of the wave shape, and has an influence on the aerodynamic and noise performance of the blade. The wave crest position is currently 0.85R, and the noise reduction effect is best. The main interval of r2 is 0.75R≤r2≤0.95R.

[0122] The wave crest amplitude A: the wave crest amplitude A affects the size of the wave crest. The larger the amplitude, the higher the wave crest, and the better the noise reduction effect (the sound source intensity is weakened, and the phase interference is enhanced). However, the aerodynamic performance will be lost. In the embodiment of the present application, A is taken as 0.073R, and the main interval of A is 0.035R≤A≤0.15R.

[0123] The wave crest width d: the wave crest width d is the difference between the wave starting position and the wave ending position. The wave crest width d will affect the wave shape, and then affect the noise and aerodynamic performance. After the wave starting position r1 is determined, the wave crest width is only affected by the ending position. In the embodiment of the present application, the wave ending position can be the blade tip, so the wave crest width is 0.25R, and the main interval of d is 0.15R≤A≤0.35R.

[0124] In addition, it should be noted that the blade of the present application can also achieve the purpose of noise reduction through the down-reflection design at the blade tip.

[0125] The paddle of the embodiment of the present application realizes the hovering endurance time of the quadrotor unmanned aerial vehicle without loss, does not produce the safety problem of high temperature rise of the motor, and can realize single-paddle noise reduction of 4dB and whole machine noise reduction of 3.5dB compared with the consistent speed efficiency of the conventional paddle, which can meet the noise index requirements of the corresponding regional regulations.

[0126] The embodiment of the present application also realizes Figure 14 to Figure 22 It is shown that the paddle 10 with the convex structure 1011 has low noise and does not significantly reduce the aerodynamic performance after optimization design. The following will be described in detail respectively: Figure 14 to Figure 22

[0127] Figure 14 The different color patterns in the figure each represent that the wave crest amplitude A of the convex structure 1011 is 0.73R, the wave crest radius r2 is the projection of the paddle 10 along the thickness direction when different parameters, the horizontal axis represents the proportion of each part of the paddle to the paddle radius R, and the vertical axis represents the chord length to the paddle radius R. For example, the blue line represents the conventional paddle (without the convex structure 1011) of the comparative configuration, the red dotted line represents the paddle configuration when the wave crest radius r2 of the convex structure 1011 is 0.75R, the black solid line represents the paddle configuration when the wave crest radius r2 of the convex structure 1011 is 0.85R, and the green dotted line represents the paddle configuration when the wave crest radius r2 of the convex structure 1011 is 0.95R.

[0128] Figure 15 For Figure 14 The noise reduction comparison of the paddles of different configurations used in the whole machine of the aircraft, the horizontal axis represents the ratio of the wave crest radius r2 to the paddle radius R, and the vertical axis represents the sound power reduction of the whole machine, unit: dB. From Figure 15 It can be seen that as r2 increases from 0.75R to 0.85R, the sound power reduction of the whole machine gradually increases, when r2=0.85R, the sound power reduction of the whole machine reaches the maximum value close to 3.5dB, and as r2 increases from 0.85R to 0.95R, the sound power reduction of the whole machine gradually decreases. Thus, when r2=0.85R and A=0.73R of the convex structure 1011, the paddle of this configuration has a significant low noise effect.

[0129] Figure 16 ​The different colors of the graphs each represent that the peak radius r2 of the protruding structure 1011 is 0.85R, and the projection of the paddle 10 along the thickness direction when the peak amplitude A is a different parameter. The horizontal axis represents the proportion of each part of the paddle to the paddle radius R, and the vertical axis represents the proportion of the chord length to the paddle radius R. For example, the blue line represents the conventional paddle of the comparative configuration (without the protruding structure 1011), the red dashed line represents the paddle configuration when the peak amplitude A of the protruding structure 1011 is -0.073R, the black solid line represents the paddle configuration when the peak amplitude A of the protruding structure 1011 is 0.0365R, the green dashed line represents the paddle configuration when the peak amplitude A of the protruding structure 1011 is 0.073R, and the yellow dashed line represents the paddle configuration when the peak amplitude A of the protruding structure 1011 is 0.102R.

[0130] Figure 17 For Figure 16 The noise reduction comparison of the paddles of different configurations when used in the aircraft as a whole, the horizontal axis represents the ratio of the peak amplitude A to the paddle radius R, and the negative number represents the concave in the peak. The vertical axis represents the sound power reduction amount of the whole, in dB. From Figure 17 It can be seen that as the peak amplitude A increases from -0.1R to 0.12R, the sound power reduction amount of the whole gradually increases. Thus, the greater the peak amplitude A of the protruding structure 1011, the more conducive to noise reduction.

[0131] Figure 18 The sound pressure level curves of the conventional paddle of the comparative configuration (without the protruding structure 1011) and the paddle with the protruding structure 1011 when installed on the aircraft as a whole, respectively, at different frequencies. Among them, the weight of the aircraft as a whole is about 1220g, the horizontal axis represents the frequency of the paddle rotation, and the vertical axis represents the sound pressure level. The green solid line is the sound pressure level curve of the conventional paddle. The red dashed line is the sound pressure level curve of the paddle with the protruding structure 1011. From the graph, it can be seen that when the frequency exceeds 1000Hz, the red dashed line is significantly lower than the green solid line, and thus the paddle with the protruding structure 1011 has lower noise.

[0132] Figure 19 The noise performance of two different configurations of paddles on the aircraft as a whole, the horizontal axis represents the weight of the whole, in g, and the vertical axis represents the sound power of the whole, in dBA. The star point represents the sound power of the whole of the conventional paddle of the comparative configuration (without the protruding structure 1011), and the circle point represents the sound power of the whole of the paddle with the protruding structure 1011. From the graph, it can be seen that at the same weight of the whole, the sound power of the whole of the paddle with the protruding structure 1011 is significantly lower than that of the conventional paddle, and the low-noise effect is significant.

[0133] Figure 20is the single propeller noise performance of two different propeller configurations, the horizontal axis represents the frequency of the propeller rotation, the vertical axis represents the sound pressure level, the blue solid line is the sound pressure level curve of the conventional propeller of the comparative configuration, and the yellow solid line is the sound pressure level curve of the propeller with the protruding structure 1011. It can be seen from the figure that when the frequency is greater than about 1000 Hz, the yellow solid line is obviously lower than the blue solid line, and thus the propeller with the protruding structure 1011 has lower noise.

[0134] Figure 21 is the single propeller thrust performance of two different propeller configurations, the horizontal axis represents the rotation speed of the propeller, in rpm, and the vertical axis represents the single propeller thrust, in g, the circle dot represents the single propeller thrust of the conventional propeller of the comparative configuration (without the protruding structure 1011), and the star dot represents the single propeller thrust of the propeller with the protruding structure 1011. It can be seen from the figure that at the same rotation speed, the single propeller thrust of the propeller with the protruding structure 1011 is basically the same as that of the conventional propeller. Thus, the propeller with the protruding structure 1011 basically maintains the original aerodynamic performance, and the aerodynamic performance is not obviously reduced.

[0135] Figure 22 is the single propeller torque performance of two different propeller configurations, the horizontal axis represents the rotation speed of the propeller, in rpm, and the vertical axis represents the single propeller torque, in mNm, the circle dot represents the single propeller torque of the conventional propeller of the comparative configuration (without the protruding structure 1011), and the star dot represents the single propeller torque of the propeller with the protruding structure 1011. It can be seen from the figure that at the same rotation speed, the single propeller torque of the propeller with the protruding structure 1011 is basically the same as that of the conventional propeller. Thus, the propeller with the protruding structure 1011 basically maintains the original aerodynamic performance, and the aerodynamic performance is not obviously reduced.

[0136] The apparatus embodiments described above are merely illustrative, wherein the units shown as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0137] As referred to herein, "one embodiment", "an embodiment" or "one or more embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

[0138] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0139] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof. In a unitary claim, several devices or sub-claims can be joined by means of the word 'or'. The word 'first','second', 'third', etc. do not imply any order. The terms 'first','second', 'third', etc. are to be interpreted according to their meaning in the context and are not to be interpreted as a ranking.

[0140] It has to be noted that, while the above describes example embodiments of the application, these are merely given by way of non-limiting examples. Many variations and modifications of the embodiments described herein can become apparent to those skilled in the art once they are made aware of the general inventive concept. It is therefore contemplated that the application shall also cover any variations and modifications to the above described embodiments that fall within the scope of the claims.

Claims

1. A paddle, characterized in that, The blade is applied to an aircraft, and the blade comprises: a leading edge comprising a convex structure protruding outward, the convex structure being located at one end of the leading edge relatively close to a blade tip of the blade, wherein the size of A satisfies the following relationship: 0.035R≤A≤0.15R, R representing a distance from a rotation center of the blade to the blade tip, the rotation center representing a position of a rotation axis of the blade when the blade is installed on a driver of the aircraft.

2. The paddle of claim 1, wherein A=0.073R.

3. The paddle of claim 1, wherein, A represents a distance between a first peak point of the convex structure and a first intersection point, the first intersection point representing an intersection of a chord line at the first peak point and a first extension line, the first extension line representing an extension line starting from a first leading edge part in the leading edge and passing through a first starting point of the convex structure, the first leading edge part representing a part of the leading edge outside the convex structure and close to the first starting point.

4. The paddle of claim 1, wherein, Along a radial direction of the blade, from the rotation center to the blade tip, the blade comprises, in sequence, a blade root part, a blade body part and a blade tip part, and the convex structure is located at the blade tip part.

5. The paddle of claim 1, wherein, The convex structure comprises a first connecting segment and a second connecting segment, along the radial direction of the blade, the first connecting segment corresponding to a part of the convex structure extending from a first starting point to a first peak point, and the second connecting segment corresponding to another part of the convex structure extending from the first peak point to a first end point.

6. The paddle of claim 5, wherein, The first connecting segment is relatively far away from the blade tip, and the second connecting segment is relatively close to the blade tip.

7. The paddle of claim 5, wherein, From the direction of the rotation center to the blade tip, the first connecting segment has an upward trend, and the second connecting segment has a downward trend.

8. The paddle of claim 7, wherein, A distance parameter between the first starting point and the rotation center is r1, and 0.65R≤r1≤0.8R.

9. The paddle of claim 8, wherein, r1＝0.75R。 10. The paddle of claim 7, wherein, A distance parameter between the first peak point and the rotation center is r2, and 0.75R≤r2≤0.95R.

11. The paddle of claim 10, wherein, r2＝0.85R。 12. The paddle of claim 7, wherein, A distance parameter between the first starting point and the first end point is d, and 0.15R≤d≤0.35R.

13. The paddle of claim 12, wherein, d=0.25R.

14. The paddle of claim 1, wherein, The blade further comprises a trailing edge arranged opposite to the leading edge, the trailing edge comprising a specific part corresponding to the convex structure, the specific part being located at one end of the trailing edge relatively close to the blade tip of the blade, wherein a flatness of the specific part is greater than a flatness of the convex structure.

15. The paddle of claim 1, wherein, The blade further comprises a trailing edge arranged opposite to the leading edge, the trailing edge comprising a concave structure, the concave structure having a size of B, and the sizes of A and B satisfying the following relationship: 0 16. The paddle of claim 15, wherein, The size of B satisfies the following relationship: 0 17. The paddle of claim 16, wherein, B=0.026R.

18. The paddle of claim 16, wherein, Along the radial direction of the blade, from the rotation center to the blade tip, the blade comprises, in sequence, a blade root part, a blade body part and a blade tip part, and the concave structure is located at the blade tip part.

19. The paddle of claim 18, wherein, B represents a distance between a second peak point of the concave structure and a second intersection point, the second intersection point representing an intersection between a chord line at the second peak point and a second extension line, the second extension line representing an extension line starting from a first trailing edge portion in the trailing edge and passing a second starting point of the concave structure, the first trailing edge portion representing a portion in the trailing edge outside the concave structure and close to the second starting point.

20. The paddle of claim 15, wherein, The concave structure comprises a third connecting segment and a fourth connecting segment, the third connecting segment corresponding to a portion of the concave structure extending from the second starting point to the second peak point along a radial direction of the blade, and the fourth connecting segment corresponding to another portion of the convex structure extending from the second peak point to the second ending point.

21. The paddle of claim 20, wherein, The third connecting segment is relatively far away from the blade tip, and the fourth connecting segment is relatively close to the blade tip.

22. The paddle of claim 21, wherein, The third connecting segment has an upward trend, and the fourth connecting segment has a downward trend, in a radial direction from the rotation center to the blade tip.

23. The paddle of claim 14, wherein, The portion of the trailing edge corresponding to the convex structure is continuously and gently arranged.

24. The paddle of claim 23, wherein, The slope of the portion of the trailing edge corresponding to the convex structure is substantially the same.

25. The paddle of claim 23, wherein, The portion of the trailing edge between a first position point and a second position point represents the portion corresponding to the convex structure, the first position point representing an intersection of a chord line at the first starting point of the convex structure on the trailing edge, and the second position point representing an intersection of a chord line at the first ending point of the convex structure on the trailing edge.

26. The paddle of claim 25, wherein, An extension line between the first position point and a third position point passes through the blade tip, the third position point representing an intersection of a chord line at the first peak point of the convex structure on the trailing edge.

27. The paddle of claim 1, wherein, The blade is a blade of a lightweight material.

28. The paddle of claim 27, wherein, The blade is made of any one of the following materials: a plastic material, a fiber material, an alloy material, and a fiber composite material.

29. The paddle of claim 27, wherein, The blade comprises, in sequence, a root portion, a body portion, and a tip portion along a radial direction of the blade from the rotation center to the blade tip.

30. The paddle of claim 29, wherein, From the rotation center to the blade tip, the root portion has at least one region with a gradually increasing corresponding chord length.

31. The paddle of claim 30, wherein, From the rotation center to the blade tip, the chord length of the root portion gradually increases.

32. The paddle of claim 31, wherein, From the rotation center to the blade tip, the body portion has at least one region with a gradually decreasing corresponding chord length.

33. The paddle of claim 32, wherein, From the rotation center to the blade tip, the chord length of the body portion gradually decreases.

34. A paddle, characterized by The blade is applied to an aircraft, and the blade comprises: a leading edge comprising a convex structure protruding outward, the convex structure being located at an end of the leading edge relatively close to a blade tip of the blade; and a trailing edge arranged opposite to the leading edge, the trailing edge comprising a specific portion corresponding to the convex structure, the specific portion being located at an end of the trailing edge relatively close to the blade tip of the blade; wherein the specific portion has a gentleness greater than that of the convex structure.

35. A propeller, characterized by The propeller comprises: a propeller seat; and the blade of any one of claims 1 to 34, a root portion of the blade being connected to the propeller seat.

36. The propeller of claim 35, wherein, The number of the blades is at least two, each of the blades is connected with the hub, and at least two of the blades are uniformly arranged around the center of the hub, which is the rotation center.

37. A power module, characterized by The power module comprises: The propeller of claim 35 or claim 36; and A driver connected with the propeller, the driver being used to drive the propeller to rotate.

38. An aircraft characterized by: The aircraft comprises the power module of claim 37.

Images