WO2021109441A1 - 旋翼飞行器的旋翼及旋翼飞行器 - Google Patents
旋翼飞行器的旋翼及旋翼飞行器 Download PDFInfo
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- WO2021109441A1 WO2021109441A1 PCT/CN2020/088363 CN2020088363W WO2021109441A1 WO 2021109441 A1 WO2021109441 A1 WO 2021109441A1 CN 2020088363 W CN2020088363 W CN 2020088363W WO 2021109441 A1 WO2021109441 A1 WO 2021109441A1
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- rotor
- airfoil
- wing surface
- blade
- rotorcraft
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
- B64C27/46—Blades
- B64C27/467—Aerodynamic features
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
- B64C27/46—Blades
- B64C27/473—Constructional features
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C3/00—Wings
- B64C3/10—Shape of wings
Definitions
- the present disclosure relates to the technical field of aircraft, and in particular to a rotor of a rotorcraft and a rotorcraft.
- the airfoil of the rotorcraft plays an important role in improving aerodynamic efficiency.
- the existing rotors are mainly designed around large manned aircraft, which are usually in high Reynolds numbers (generally above 1000,000). At present, there are few researches on the rotors of aircrafts under the flow of low Reynolds number (below 500,000), such as logistics distribution, plant protection, and aerial photography.
- Existing rotors generally have problems such as low lift coefficient and low lift-to-drag ratio under low Reynolds number flow, which makes the aerodynamic efficiency of rotor drones low.
- the present disclosure provides a rotor of a rotorcraft, which includes a blade and a hub.
- the blade is mounted on a drive assembly of the rotorcraft through the hub.
- the present disclosure also provides a rotary wing aircraft, which has the above-mentioned rotary wing.
- the rotor of the rotorcraft provided by the present disclosure has a higher maximum lift coefficient and a higher lift-to-drag ratio under a low Reynolds number flow, thereby being able to improve the aerodynamic efficiency of the rotorcraft.
- the aerodynamic efficiency of the rotorcraft improved, under the same lifting surface distribution, the required rotor speed is lower, which can reduce the noise generated during the flight of the rotorcraft.
- Fig. 1 is a schematic diagram showing an airfoil profile of a blade of a rotor wing according to an exemplary embodiment
- Fig. 12 is a schematic diagram showing a three-dimensional structure of a blade of a rotor wing according to an exemplary embodiment
- Fig. 13 is a plan view of a blade of a rotor according to an exemplary embodiment
- Fig. 14 is a comparison diagram of the force effect between the blade of the present disclosure and the pure carbon blade of T-motor.
- azimuth terms such as upper and lower appearing in this embodiment are based on the normal operating attitude of the rotor and the rotorcraft after the rotor is installed on the aircraft, and should not be considered as restrictive.
- the present disclosure provides a rotor of a rotorcraft.
- the rotor includes a blade 1 and a hub.
- the blade 1 is installed on a drive assembly of the rotorcraft through the hub.
- the driving component may be, for example, a rotating electric machine installed on the fuselage of the rotorcraft, and the output shaft of the rotating electric machine is connected to the hub to drive the blade 1 to rotate.
- the fuselage of the rotorcraft can be equipped with multiple rotors. By adjusting the rotation speed and attitude of the rotors, the flight attitude of the rotorcraft can be changed to switch between hovering, traveling, or tilting.
- the blade 1 of the present disclosure can be made of any material in the related art, including but not limited to metal materials, plastics, carbon fibers, and the like.
- processing techniques in various related technologies such as molding, stamping, forging, etc. can be used in manufacturing.
- the airfoil of the blade 1 of the rotor of the present disclosure is composed of a leading edge 11, a trailing edge 12, and an upper arc line 13 and a lower arc line 14 located between the leading edge 11 and the trailing edge 12.
- the present disclosure moves the position of the largest thickness a in the airfoil to the trailing edge 12, thereby avoiding air flow on the airfoil of the rotor blade 1 Airflow separation occurs prematurely at arc 13, resulting in loss of lift.
- the front boundary layer of the airfoil is more stable, and the separation point is delayed, which is beneficial to the work done at the upper arc surface of the front part of the airfoil.
- the rotor of the rotorcraft of the present disclosure has a high maximum lift coefficient and a high lift-drag ratio under low Reynolds number flow, exhibits relatively excellent aerodynamic efficiency, and generates the same lift. In the case of consuming less power, or consuming the same power, it can generate more lift.
- the aerodynamic noise generated by the rotor during high-speed rotation is the main noise source of the rotorcraft. Due to the improvement of the aerodynamic efficiency of the rotorcraft, under the same lifting surface distribution, the required rotor speed is lower, which can effectively reduce the noise generated during the flight of the rotorcraft and improve the user experience.
- the upper arc 13 may be defined by the upper arc coordinate value pair (x/c, yu /c), and the lower arc 14 may be defined by the lower arc coordinate Limited by the value pair (x/c, y l /c), the upper arc coordinate value pair (x/c, y u /c) and the lower arc coordinate value pair (x/c, y l /c) Can be defined according to Table 1:
- y u is the vertical distance between the upper arc 13 and the chord
- y l is the vertical distance between the lower arc 14 and the chord 15.
- the maximum error of each of the upper arc coordinate value pair x/c, y u /c and the lower arc coordinate value pair x/c, y l /c in the present disclosure is equal to ⁇ 3%, that is, within ⁇ 3%
- the contour of the airfoil enclosed by the upper arc coordinate value pair x/c, y u /c and the lower arc coordinate value pair x/c, y l /c within the allowable error range falls within the requirements of the present disclosure
- the airfoil obtained within the protection range of and within the error range can still achieve the beneficial effects of the above-mentioned airfoil.
- the coordinate pairs used in the present disclosure to define the airfoil profile are dimensionless coordinate values. In this way, the data in Table 1 above is scaled up or down in equal proportions without changing the shape of the airfoil.
- the maximum lift coefficient of the E376 airfoil of the present disclosure can be increased by at least 17% compared with the VR7 airfoil.
- the lift coefficient of the E376 airfoil of the present disclosure is overall higher than that of the VR7 airfoil.
- the maximum lift-drag ratio of the E376 airfoil of the present disclosure can be increased by at least 21%.
- the lift-drag ratio of the E376 airfoil of the present disclosure is overall higher than that of the VR7 airfoil.
- the maximum lift coefficient and maximum lift-drag ratio of the E376 airfoil and VR7 airfoil of the present disclosure are significantly improved under low Reynolds number, which proves that the rotor using the airfoil of the present disclosure has higher aerodynamic efficiency, Lighter weight.
- the required speed is lower, so it can effectively reduce the noise generated during the flight of the rotorcraft, especially in densely populated areas. During the logistics and distribution, it can minimize the interference to the lives of surrounding residents and enhance the user experience.
- the blade 1 of the present disclosure includes a blade root 16, a blade tip 17, and an upper wing surface 18 and a lower wing surface 19 arranged opposite to each other up and down.
- One side of 18 and the lower airfoil 19 is connected to form a leading edge 11, and the other side is connected to form a trailing edge 12.
- the part of the blade 1 extending from its radius 35% to the tip 17 has the airfoil shape.
- the portion of the blade 1 of the present disclosure extending from its radius of 35% to the tip 17 has the above-mentioned airfoil shape of the present disclosure. Therefore, the blade 1 of the present disclosure has all the beneficial effects of the above-mentioned airfoil shape.
- the reason why not all segments of the blade 1 of the present disclosure adopt the above-mentioned airfoil shape is that the blade root 16 is used to connect with the hub, so that the hub can rotate under the drive of the drive assembly.
- the root 16 is closer to the hub than the main part of the blade 1 and the tip 17 part, so it will withstand higher output torque.
- the blade 1 of the present disclosure may be thickened before 35% of its radius.
- the rotational linear velocity of the blade 1 of the present disclosure before 35% of its radius is low, and therefore the contribution to lift is less, so even if the airfoil of this part is different from the above-mentioned airfoil of the present disclosure
- the shape will not have a substantial impact on force efficiency and aerodynamic efficiency. It should be understood that, in the overall structure of the blade 1 of the present disclosure, there is no technical obstacle to adopting all the above-mentioned airfoils of the present disclosure.
- the rotor of the present disclosure can be in the best working section along the span of the blade 1 to reduce air resistance, improve pulling force and efficiency, thereby increasing the endurance time of the rotorcraft, and also reducing the flight time of the aircraft.
- the noise generated during flight enhances the user experience.
- the upper wing surface 18 is formed by the upper wing surface characteristic line (kx, ky, kz) defined by a plurality of coordinate pairs (x, y, z), and the lower wing surface 19 is formed by passing through a plurality of coordinate pairs (x, y, z)
- the lower wing surface characteristic line formed by the defined (kx, ky, kz) is formed, and the upper wing surface characteristic line and the lower wing surface characteristic line are defined according to Table 4a and Table 4b:
- Table 4a Feature point coordinates of the feature line of the upper wing surface
- Table 4b Feature point coordinates of the feature line of the lower wing surface
- the x direction is the span direction of the rotor
- the y direction is the chord direction of the rotor
- the z direction is the thickness direction of the rotor.
- k a/229, where a is the radius of the rotor.
- the blades and the hub are connected up and down, the blade radius is equal to the radius of the rotor, and the blade radius is the distance from the center of rotation to the tip of the blade.
- the blade radius is half the length of the blade.
- the clusters are also within the scope of the implementation of the present disclosure, and there are smooth transitions between the characteristic lines.
- the following exemplarily provides a method of how to obtain a blade with the same shape as the present disclosure under the condition of selecting blades of other radius sizes.
- the corresponding coordinates in the characteristic line e of the upper wing surface in Table 4a become (297.60030, -31.16505, 7.31181), (297.60030, -30.85444, 7.64422)...; the corresponding coordinates in the characteristic line e of the lower wing surface in Table 4b become (297.60030, -31.16505,7.31181), (297.60030,-31.01191,6.97195)...
- the maximum error of each of the upper wing surface characteristic line and the lower wing surface characteristic line is equal to ⁇ 3%, that is, the wing formed by the upper wing surface characteristic line and the lower wing surface characteristic line within the allowable range of ⁇ 3%
- ⁇ 3% the wing formed by the upper wing surface characteristic line and the lower wing surface characteristic line within the allowable range of ⁇ 3%
- the blade 1 of the present disclosure has a three-dimensional structure defined by the above three characteristic lines in an interval far from the center (roughly the interval where x is 113-196).
- the blade structure corresponding to this interval is the main structure of the blade, which is a relatively important tensile force generation area.
- the span direction of the main part of the blade 1 can be in a better working section.
- it can also reduce the noise generated by the aircraft during flight and improve the user experience.
- the upper wing surface characteristic line and the lower wing surface characteristic line are further defined according to Table 5a and Table 5b:
- Table 5a Feature point coordinates of the upper wing surface feature line
- Table 5b Feature point coordinates of the feature line of the lower wing surface
- an interval closer to the center (approximately x 27-69 interval) is selected for optimization.
- the blade root 16 is closer to the hub than the main part of the blade 1 and the tip 17 part, so it will withstand higher torque.
- thickening is performed on the portion of the paddle root 16 in this interval, that is, a bulge is formed outward along the chord direction of the paddle root 16 to improve the structural strength of the paddle root 16.
- the upper wing surface characteristic line and the lower wing surface characteristic line are further defined according to Table 6a and Table 6b:
- Table 6a Feature point coordinates of the upper wing surface feature line
- Table 6b Feature point coordinates of the feature line of the lower wing surface
- the present disclosure further refines the main part of the blade 1 so that the transition of the main part of the blade 1 is smoother, and no sharp torsion occurs.
- This smooth transition structure can further improve the overall structural strength of the blade 1 and is not easy to break, thereby improving the reliability of the main part of the blade 1 during operation, and making the pulling force and efficiency higher.
- the upper wing surface characteristic line and the lower wing surface characteristic line are further defined according to Table 7:
- Table 7 Feature point coordinates of upper wing surface characteristic line and lower wing surface characteristic line
- the present disclosure further refines the area of the closer blade root 16 to improve the smoothness of the blade root 16 to improve the structural strength of the blade 1.
- each section of the rotor of the present disclosure can be in the optimal working section along the span of the blade 1, so as to reduce the resistance of the air, improve the pulling force and efficiency, so as to increase the rotorcraft. In addition, it can reduce the noise generated by the aircraft during flight and improve the user experience.
- a swept back portion 171 is also formed at the wing tip 17, and the swept back portion 171 is bent and extends from the leading edge 11 to the trailing edge 12, and the swept back portion 171
- the upper wing surface characteristic line and the lower wing surface characteristic line are defined according to Table 8a and Table 8b:
- Table 8a Feature point coordinates of the upper wing surface feature line
- Table 8b Feature point coordinates of the feature line of the lower wing surface
- the x direction is the span direction of the rotor
- the y direction is the chord direction of the rotor
- the z direction is the thickness direction.
- k a/229, where a is the radius of the rotor.
- the following exemplarily provides a way of how to obtain the swept part 171 with the same shape as the present disclosure when the blades of other radius sizes are selected.
- the corresponding coordinates in the characteristic line j of the upper wing surface in Table 8a become (549.60056,-22.77924,2.38606), (549.60056,-22.77924, 2.58626)...
- the corresponding coordinates in the characteristic line j of the lower wing surface in Table 8b become (549.60056,-22.77924,2.38606), (549.60056,-22.67366,2.21162)...
- the maximum error of each of the upper wing surface characteristic line and the lower wing surface characteristic line is equal to ⁇ 3%, that is, the wing formed by the upper wing surface characteristic line and the lower wing surface characteristic line within the allowable range of ⁇ 3%
- ⁇ 3% the wing formed by the upper wing surface characteristic line and the lower wing surface characteristic line within the allowable range of ⁇ 3%
- the three-dimensional structure formed by the above two airfoil feature lines has a sweeping portion 171, the existence of which can cut off the spanwise flow of air on the blade 1 when the blade 1 rotates, thereby Reduce the vortex formed by the tip 17 part, and reduce the strength of the vortex at the tip 17 part.
- the sweeping portion 171 can also weaken the degree of air pressure changes near the blade 1, and weaken the periodic cutting airflow of the blade 1 with a certain thickness. In the end, the rotating noise generated when the blade 1 rotates is finally reduced.
- the present disclosure further adds an airfoil characteristic line to define the swept part.
- the concrete table 9 shows:
- Table 9 Feature point coordinates of the upper wing surface characteristic line and the lower wing surface characteristic line
- the swept portion 171 is made smoother, the vortex formed at the blade tip 17 is more stable, and the noise reduction effect can be further improved.
- the power efficiency of the rotorcraft using the blade 1 of the present disclosure is improved by an average of 4.9% compared with the T-motor pure carbon blade. Specifically, under a pulling force of 1.5 kg, the force efficiency is increased by 2.7%; under a pulling force of 1.1 kg, the force effect is increased by 5%; and under a pulling force of 1.8 kg, the pulling force is increased by 7%.
- the noise of the blade 1 of the present disclosure is reduced by 3 decibels compared with the pure carbon blade of the T-motor.
- the aforementioned force effect test of the present disclosure adopts dual methods of numerical simulation and wind tunnel test to ensure the accuracy of the experimental results.
- FIG. 13 there may be at least two blades 1, and at least two blades 1 are connected together by a blade root 16, and are opposite to the blade roots of the at least two blades 1.
- the position of the center point of the 16 connection is center-symmetrical.
- At least two blades 1 can be integrally formed, so as to ensure the overall structural strength of the blade 1; or the blade 1 can also be designed to be formed separately, for example, each blade 1 is installed on the hub separately, so that The installation and replacement of the blade 1 is more convenient.
- the center of rotation of the blade 1 is the axis where the hub is located.
- the present disclosure also provides a rotary wing aircraft, which includes the above-mentioned rotary wing.
- the rotorcraft has all the beneficial effects of the rotorcraft of the above rotorcraft, which will not be repeated in this disclosure.
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Abstract
一种旋翼飞行器的旋翼及旋翼飞行器,其中旋翼飞行器的旋翼,包括桨叶(1)和桨毅,桨叶通过桨毅安装于旋翼飞行器的驱动组件上,桨叶的翼型由前缘(11)、尾缘(12)以及位于前缘和尾缘之间的上弧线(13)和下弧线(14)构成,桨叶的翼型的最大厚度a与翼型的弦长c之比为a/c=6.85%,最大厚度位于x/c=30.5%处;桨叶的翼型的最大弯度b与翼型的弦长c之比为b/c=6.6%,最大弯度b位于x/c=47.1%处。
Description
本公开涉及飞行器技术领域,具体地,涉及一种旋翼飞行器的旋翼及旋翼飞行器。
为提高旋翼飞行器的气动效率,需要在产生同样升力的情况下尽可能地降低所消耗的功率,或者在消耗同样功率的情况下产生尽可能较大的升力。气动效率的提高对于提高飞行器的航时、航程以及载重能力都具有重要的意义。
旋翼飞行器的翼型对于提高气动效率具有重要的作用。现有旋翼主要是围绕大型有人飞机进行设计,大型有人飞机通常处于高雷诺数(普遍处于1000,000以上)的流动中。而目前针对例如物流配送、植保、航拍等多处于低雷诺数(500,000以下)的流动下的飞行器的旋翼研究较少。现有旋翼在低雷诺数流动下普遍存在升力系数偏低、升阻比偏低等问题,使得旋翼无人机的气动效率较低。
发明内容
本公开提供一种旋翼飞行器的旋翼,包括桨叶和桨毂,所述桨叶通过桨毂安装于旋翼飞行器的驱动组件上,所述桨叶的翼型由前缘、尾缘以及位于所述前缘和尾缘之间的上弧线和下弧线构成,所述桨叶的翼型的最大厚度a与翼型的弦长c之比为a/c=6.85%,所述最大厚度位于x/c=30.5%处;所述桨叶的翼型的最大弯度b与翼型的弦长c之比为b/c=6.6%,所述最大弯度b位于x/c=47.1%处;其中,x是沿着弦线从所述前缘到所述尾缘的距离,所述a/c、b/c、x/c的值分别具有±3%的最大误差。
本公开还提供一种旋翼飞行器,该旋翼飞行器具有上述旋翼。
通过上述技术方案,本公开提供的旋翼飞行器的旋翼在低雷诺数流动下具有更高的最大升力系数以及更高的升阻比,从而能够提高旋翼飞行器的气动效率,此外由于旋翼飞行器气动效率的提高,在同样的升力面分布的情况下,所需要的旋翼转速更低,能够减小旋翼飞行器飞行过程中产生的噪音。
本公开的其他特征和优点将在随后的具体实施方式部分予以详细说明。
附图是用来提供对本公开的进一步理解,并且构成说明书的一部分,与下面的具体实施方式一起用于解释本公开,但并不构成对本公开的限制。在附图中:
图1是根据一示例性实施例示出的旋翼的桨叶的翼型轮廓示意图;
图2是本公开的翼型与VR7的翼型在低雷诺数Re=1.3×10
4时最大升力系数曲线对比图;
图3是本公开的翼型与VR7的翼型在低雷诺数Re=2.7×10
4时最大升力系数曲线对比图;
图4是本公开的翼型与VR7的翼型在低雷诺数Re=4×10
4时最大升力系数曲线对比图;
图5是本公开的翼型与VR7的翼型在低雷诺数Re=1.8×10
5时最大升力系数曲线对比图;
图6是本公开的翼型与VR7的翼型在低雷诺数Re=4×10
5时最大升力系数曲线对比图;
图7是本公开的翼型与VR7的翼型在低雷诺数Re=1.3×10
4时最大升阻比曲线对比图;
图8是本公开的翼型与VR7的翼型在低雷诺数Re=2.7×10
4时最大升阻比曲线对比图;
图9是本公开的翼型与VR7的翼型在低雷诺数Re=4×10
4时最大升阻比曲线对比图;
图10是本公开的翼型与VR7的翼型在低雷诺数Re=1.8×10
5时最大升阻比曲线对比图;
图11是本公开的翼型与VR7的翼型在低雷诺数Re=4×10
5时最大升阻比曲线对比图;
图12是根据一示例性实施例示出的旋翼的桨叶的立体结构示意图;
图13是根据一示例性实施例示出的旋翼的桨叶的平面视图;
图14是本公开的桨叶与T-motor纯碳桨叶的力效对比图。
以下结合附图对本公开的具体实施方式进行详细说明。应当理解的是,此处所描述的具体实施方式仅用于说明和解释本公开,并不用于限制本公开。
本实施例中出现的上、下等方位用语是以旋翼安装于飞行器以后旋翼以及旋翼飞行器的常规运行姿态为参考,而不应该认为具有限制性。
下面结合附图,对本公开的旋翼飞行器的旋翼及旋翼飞行器进行详细说明。在不冲突的情况下,下述的实施例及实施方式中的特征可以相互组合。
如图12和图13所示,本公开提供了一种旋翼飞行器的旋翼,旋翼包括桨叶1和桨毂,桨叶1通过桨毂安装于旋翼飞行器的驱动组件上。驱动组件例如可以是安装在旋翼飞行器机身上的旋转电机,旋转电机的输出轴与桨毂连接,以带动桨叶1旋转。旋翼飞行器的机身上可以设置多个旋翼,通过对旋翼的旋转速度以及姿态的调节,能够改变旋翼飞行器的飞行姿态,以在悬停、行进或者侧倾等动作之间切换。
本公开的桨叶1可以采用相关技术中的任意材质制成,包括但不限于金属材料、塑料、碳纤维等。此外,在制造时可以采用模塑、冲压、锻造等各种相关技术中的加工工艺手段。
如图1所示,本公开旋翼的桨叶1翼型由前缘11、尾缘12以及位于前缘11和尾缘12之间的上弧线13和下弧线14构成。桨叶1的翼型的最大厚度a与翼型的弦长c之比为a/c=6.85%,其中,最大厚度位于x/c=30.5%处;桨叶的翼型的最大弯度b与翼型的弦长c之比为b/c=6.6%,其中,最大弯度b位于x/c=47.1%处;其中,x是沿弦线15从前缘11到尾缘12的距离,a/c、b/c、x/c分别具有±3%的最大误差,即在±3%误差允许范围内由a/c、b/c、x/c构成的翼型的轮廓均落入到本公开所要求的保护的范围内。
与现有旋翼的翼型相比,考虑到低雷诺数流动的特点,本公开将翼型中最大厚度a的位置向尾缘12移动,从而避免了气流在旋翼的桨叶1翼型的上弧线13处过早的出现气流分离,而导致升力损失。此外通过对最大厚度a以及最大弯度b的改进,翼型的前段边界层更加的稳定,推迟了分离点,有利于翼型前段上弧面处的做功。
基于上述技术方案和理论分析,本公开的旋翼飞行器的旋翼在低雷诺数流动下,具有较高的最大升力系数以及较高的升阻比,表现出了相对优异的气动效率,在产生同样升力的情况下能够消耗更少的功率,或者在消耗同样的功率的情况下能够产生更大的升力。此外,旋翼在高速旋转时产生的气动噪音是旋翼飞行器的主要噪声来源。由于旋翼飞行器气动效率的提高,在同样的升力面分布的情况下,所需要的旋翼转速更低,因而能够有效的减少旋翼飞行器飞行过程中产生的噪音,提升用户体验。
根据本公开的一种实施方式,如图1所示,上弧线13可以由上弧线坐标数值对(x/c,y
u/c)所限定,下弧线14可以由下弧线坐标数值对(x/c,y
l/c)所限定,上弧线坐标数值对(x/c,y
u/c)和所述下弧线坐标数值对(x/c,y
l/c)可以根据表1限定:
表1 翼型上下弧线特征点坐标
其中,y
u是上弧线13与弦线15的垂直距离,y
l是下弧线14与弦线15的垂直距离。
本公开中的上弧线坐标数值对x/c,y
u/c和下弧线坐标数值对x/c,y
l/c中的每个的最大误差等于±3%,即在±3%误差允许范围内的上弧线坐标数值对x/c,y
u/c和下弧线坐标数值对x/c,y
l/c所围成的翼型的轮廓均落入到本公开所要求的保护范围内,并且在误差范围内所得到的翼型仍然能够取得上述翼型所具有的有益效果。此外本公开限定翼型轮廓时所采用的坐标对为无量纲坐标值,这种方式对上述表1中的数据进行等比例的放大或缩小时,均不会改变翼型的形状。
以下将通过本公开的旋翼(E376)以及波音公司专门为垂直起降飞行器研发的旋翼(VR7)在低雷诺数流动下的气动力学比较实验,进一步说明本公开的旋翼在提升旋翼飞行器气动效率方面的有益效果。
如下表2所示,为分别选取雷诺数Re为1.3×10
4、2.7×10
4、4×10
4、1.8×10
5以及4×10
5时,在攻角为-5~15°范围内,对本公开E376翼型与波音VR7翼型的最大升力系数进行对比。在所选取的雷诺数的范围内,本公开的翼型的最大升力系数均大于VR7翼型的最大升力系数,具体的,当Re=1.3×10
4时,本公开E376翼型的最大升力系数较VR7的翼型提升了58.23%;当Re=2.7×10
4时,本公开E376翼型的最大升力系数较VR7的翼型提升了39.81%;当Re=4×10
4时,本公开E376翼型的最大升力系数较VR7的翼型提升了32.74%;当Re=1.8×10
5时,本公开E376翼型的最大升力系数较VR7的翼型提升了17.27%;当Re=4×10
5时,本公开E376翼型的最大升力系数较VR7的翼型提升了19.31%。即本公开E376翼型与VR7翼型相比最大升力系数至少能够提升17%以上。同时参考图2至图6,低雷诺数下,在翼型的有效工作点范围内,随着攻角的变化,本公开E376翼型的升力系数整体高于VR7翼型。
表2 不同雷诺数下的最大升力系数
Re | CLmax_VR7 | Clmax_E376 | 提升率 |
13000 | 0.79 | 1.25 | 58.23% |
27000 | 1.03 | 1.44 | 39.81% |
40000 | 1.13 | 1.5 | 32.74% |
180000 | 1.39 | 1.63 | 17.27% |
400000 | 1.45 | 1.73 | 19.31% |
如下表3所示,为分别选取雷诺数Re为1.3×10
4、2.7×10
4、4×10
4、1.8×10
5以及4×10
5时,在攻角为-5~15°范围内,对本公开E376翼型与波音VR7翼型的最大升阻比进行对比。在所选取的雷诺数的范围内,本公开的翼型的最大升阻比均大于VR7翼型的最大升阻比,具体的,当Re=1.3×10
4时,本公开E376翼型的最大升阻比较VR7的翼型提升了53.39%;当Re=2.7×10
4时,本公开E376翼型的最大升阻比较VR7的翼型提升了41.31%;当Re=4×10
4时,本公开E376翼型的最大升阻比 较VR7的翼型提升了37.48%;当Re=1.8×10
5时,本公开E376翼型的最大升阻比较VR7的翼型提升了28.66%;当Re=4×10
5时,本公开E376翼型的最大升阻比较VR7的翼型提升了21.27%。即本公开E376翼型与VR7翼型相比最大升阻比至少能够提升21%以上。同时参考图7至图11,低雷诺数下,在翼型的有效工作范围内,随着攻角的变化,本公开E376翼型的升阻比整体高于VR7翼型。
表3 不同雷诺数下的最大升力系数
Re | CL/CDmax_VR7 | CL/CDmax_E376 | 提升率 |
13000 | 11.5 | 17.64 | 53.39% |
27000 | 20.55 | 29.04 | 41.31% |
40000 | 26.2 | 36.02 | 37.48% |
180000 | 42.25 | 54.36 | 28.66% |
400000 | 50.72 | 61.51 | 21.27% |
通过上述对比实验,本公开E376翼型与VR7翼型在低雷诺数下,最大升力系数以及最大升阻比均具有显著的提升,证明采用本公开的翼型的旋翼具有更高的气动效率、更轻的重量。此外,由于旋翼飞行器气动效率的提高,在同样的升力面分布的情况下,所需要的转速更低,因此能够有效的减少旋翼飞行器飞行过程中产生的噪音,特别是应用于人口较为密集的区域的物流配送时,能够最大程度的减少对周围居民生活的干扰,提升用户的体验。
根据本公开的一种实施方式,如图12和图13所示,本公开的桨叶1包括桨根16、桨尖17以及上下相对设置的上翼面18和下翼面19,上翼面18和下翼面19的一侧连接形成前缘11,另一侧连接形成尾缘12,,桨叶1自其半径35%处延伸至所述桨尖17的部分具有所述翼型。
本公开的桨叶1自其半径35%处延伸至桨尖17的部分具有本公开上述的翼型,因此本公开的桨叶1就具有了上述翼型的全部有益效果。本公开的桨叶1的各段并非全部采用上述的翼型的原因在于,由于桨根16用于与桨毂相连接,从而使桨毂能够在驱动组件的驱动下旋转。桨根16相较于桨叶1的主体部分以及桨尖17部分距离桨毂更近,因此将承受更高的输出扭矩。出于结构加强的目的,本公开的桨叶1在其半径的35%处之前可以采用加厚处理。此外,在本公开的桨叶1在其半径的35%处之前的部位的旋转线速度较低,因而对于升力的贡献也较少,因此即使这一部分的翼型采用与本公开上述翼型不同的形状亦不会对力效和气动效率产生实质的影响。应当理解的是,本公开的桨叶1在整体结构上并不存在全部采用本公开上述翼型的技术障碍。
本公开的旋翼在沿着桨叶1的展向上每一段均能够处于最佳的工作段,以减少空气的阻力,提高拉力和效率,从而能够增加旋翼飞行器的续航时间,此外还能够减少飞行器在飞行时产生的噪音,提升用户体验。
上翼面18由通过多个坐标对(x,y,z)限定的(kx,ky,kz)构成的上翼面特征线形成,下翼面19由通过多个坐标对(x,y,z)限定的(kx,ky,kz)构成的下翼面特征线形成,上翼面特征线和下翼面特征线根据表4a和表4b限定:
表4a 上翼面特征线的特征点坐标
表4b 下翼面特征线的特征点坐标
其中,x方向为旋翼的展向方向,y方向为旋翼的弦长方向,z方向为旋翼的厚度方向。k=a/229,其中a为旋翼的半径取值。在一实施例中,桨叶和桨毂上下连接,桨叶半径等于旋翼半径,桨叶半径即为旋转中心至桨尖的距离,对于一体桨,桨叶半径为桨长度的一半。表4a和表4b为选取a=229即桨叶半径为229mm,k=1的桨叶的一项实施方式的立体外形数据,应当理解的是,采用该数据等比例放大或缩小而得到的曲线簇亦在本公开的实施范畴之内,各特征线之间具有平滑的过渡。
下面示例性的提供一种在选取其他半径尺寸桨叶的情况下,如何测绘得到外形与本公开相同的桨叶的方式。当桨叶的半径尺寸为600mm,即a=600,则k=2.62009,然后将k分别乘以表4a和表4b中对应的坐标值,最后得到一组新的特征线的特征点坐标,例如表4a中上翼面特征线e中对应的 坐标变为(297.60030,-31.16505,7.31181),(297.60030,-30.85444,7.64422)……;表4b中下翼面特征线e中对应的坐标变为(297.60030,-31.16505,7.31181),(297.60030,-31.01191,6.97195)……。
上翼面特征线和下翼面特征线中的每个的最大误差等于±3%,即在±3%误差允许范围内的上翼面特征线和下翼面特征线所构成的机翼的形状均落入到本公开所要求的保护的范围内。
根据表4a和4b可以看出,本公开的桨叶1中在距离中心的较远的区间内(大致x为113-196的区间)具有由上述三条特征线限定的立体结构。该区间对应的桨叶结构是桨叶中的主体结构,是较为重要的拉力产生区,通过在该区域优化特征线数值,能够使得桨叶1的主体部分的展向上处于较佳的工作段,以减少空气的阻力,提高拉力和效率,从而能够增加旋翼飞行器的续航时间,此外还能够减少飞行器在飞行时产生的噪音,提升用户体验。
本公开中,上翼面特征线和下翼面特征线还根据表5a和表5b进一步限定:
表5a 上翼面特征线的特征点坐标
表5b 下翼面特征线的特征点坐标
由于桨根16用于与桨毂相连接,从而使桨叶能够在驱动组件的驱动下旋转,因此选择距离中心较近的区间(大致x为27-69的区间)进行优化。此时桨根16相较于桨叶1的主体部分以及桨尖17部分更加靠近桨毂的位置,因此将承受更高的扭矩。本公开在该区间,即在桨根16的部分进行加厚处理,即沿着桨根16的弦向向外形成有***部,以提高桨根16部分的结构强度。
本公开中,上翼面特征线和下翼面特征线还根据表6a和表6b进一步限定:
表6a 上翼面特征线的特征点坐标
表6b 下翼面特征线的特征点坐标
可见,本公开对桨叶1的主体部分进行了进一步细化处理,使得桨叶1的主体部分的过渡更加的平滑,不会出现急扭转之处。这种平滑过渡的结构能够进一步提高桨叶1的整体结构强度,不易折断,从而提高了桨叶1主体部分在工作时的可靠性,使得拉力和效率更高。
本公开中,上翼面特征线和下翼面特征线还根据表7进一步限定:
表7 上翼面特征线和下翼面特征线的特征点坐标
可见,本公开对较近的桨根16的区域进行了进一步细化,提升了桨根16处的平滑程度,以提高桨叶1的结构强度。
进一步地,为了提升降噪的效果,本公开的旋翼在沿着桨叶1的展向上每一段均能够处于最佳的工作段,以减少空气的阻力,提高拉力和效率,从而能够增加旋翼飞行器的续航时间,此外还能够减少飞行器在飞行时产生的噪音,提升用户的使用体验。
根据本公开的一种实施方式,如图12和图13所示,在翼尖17还处形成有后掠部171,后掠部171自前缘11向尾缘12弯折延伸,后掠部171的上翼面特征线和下翼面特征线根据表8a和表8b限定:
表8a 上翼面特征线的特征点坐标
表8b 下翼面特征线的特征点坐标
其中,x方向为旋翼的展向方向,y方向为旋翼的弦长方向,z方向为厚度方向。k=a/229,其中,a为旋翼的半径取值。表8a和表8b为选取a=229即半径为229mm的桨叶的一项实施方式的立体外形数据,应当理解的是,采用该数据等比例放大或缩小而得到的曲线簇亦在本公开的实施范畴之内,特征线之间具有平滑的过渡。
下面示例性的提供一种在选取其他半径尺寸桨叶的情况下,如何得到外形与本公开相同的后掠部171的方式。例如桨叶的半径尺寸为600mm,即a=600,则k=2.62009,然后将k分别乘以表8a和表8b中对应的坐标值,最后得到一组新的特征线的特征点坐标,例如表8a中上翼面特征线j中对应的坐标变为(549.60056,-22.77924,2.38606),(549.60056,-22.77924,2.58626)……;表8b中下翼面特征线j中对应的坐标变为(549.60056,-22.77924,2.38606),(549.60056,-22.67366,2.21162)……。
上翼面特征线和下翼面特征线中的每个的最大误差等于±3%,即在±3%误差允许范围内的上翼面特征线和下翼面特征线所构成的机翼的形状均落入到本公开所要求的保护的范围内。
在本公开中,通过上述两条翼面特征线所构成的立体结构具有后掠部171,该后掠部171的存在可以切断桨叶1旋转时空气在桨叶1上的展向流动,从而减少桨尖17部分所形成的涡流,并降低桨尖17部分涡流的强度,此外后掠部171还能够削弱桨叶1附近气压变化的程度,减弱具有一定厚度的桨叶1周期性切割气流的程度,最终降低桨叶1旋转时产生的旋转噪声。
本公开进一步增加了一条翼面特征线来限定后掠部。具体地表9所示:
表9 上翼面特征线和下翼面特征线的特征点坐标
通过对后掠部171上下翼面特征线的进一步限定,使得后掠部171更加平滑,使桨尖17处形成的涡流更加稳定,能够进一步提高降噪的效果。
以下将通过本公开的桨叶(18寸电木)以及T-motor纯碳桨叶的力效对比测试,进一步说明本公开的桨叶1在提升旋翼飞行器在气动效率方面的有益效果。
如图14所示,采用本公开桨叶1的旋翼飞行器的力效与T-motor纯碳桨叶相比,平均提升4.9%。具体的,在1.5kg拉力下,力效提升2.7%;在1.1kg拉力下,力效提升5%;在1.8kg拉力下拉力提升7%。此外通过实验和数值仿真,本公开的桨叶1相较于T-motor纯碳桨叶噪声降低了3分贝。本公开上述力效的测试采用数值仿真和风洞试验双重手段,保证实验结果的准确性。
根据本公开的一种实施方式,如图13所示,桨叶1可以至少为两个,至少两个桨叶1通过桨根16连接在一起,并相对于至少两个桨叶1的桨根16连接处的中心点位置呈中心对称。至少两个桨 叶1可以一体成型,从而能够保证桨叶1的整体的结构强度;或者桨叶1也可以采用分体成型的设计,例如将每一片桨叶1分别安装到桨毂上,使得桨叶1的安装和更换较为方便,此时桨叶1的旋转中心即为桨毂所在的轴线。
本公开还提供一种旋翼飞行器,旋翼飞行器包括上述的旋翼。该旋翼飞行器具有上述旋翼飞行器的旋翼的所有有益效果,本公开对此不再赘述。
以上结合附图详细描述了本公开的优选实施方式,但是,本公开并不限于上述实施方式中的具体细节,在本公开的技术构思范围内,可以对本公开的技术方案进行多种简单变型,这些简单变型均属于本公开的保护范围。
另外需要说明的是,在上述具体实施方式中所描述的各个具体技术特征,在不矛盾的情况下,可以通过任何合适的方式进行组合。为了避免不必要的重复,本公开对各种可能的组合方式不再另行说明。
此外,本公开的各种不同的实施方式之间也可以进行任意组合,只要其不违背本公开的思想,其同样应当视为本公开所公开的内容。
Claims (12)
- 一种旋翼飞行器的旋翼,包括桨叶(1)和桨毂,所述桨叶(1)通过所述桨毂安装于所述旋翼飞行器的驱动组件上,所述桨叶(1)的翼型由前缘(11)、尾缘(12)以及位于所述前缘(11)和所述尾缘(12)之间的上弧线(13)和下弧线(14)构成,所述桨叶(1)的翼型的最大厚度a与所述翼型的弦长c之比为a/c=6.85%,所述最大厚度a位于x/c=30.5%处;所述桨叶(1)的翼型的最大弯度b与所述翼型的弦长c之比为b/c=6.6%,所述最大弯度b位于x/c=47.1%处;其中,x是沿弦线(15)方向从所述前缘(11)到所述尾缘(12)的距离,所述a/c、b/c、x/c的值分别具有±3%的最大误差。
- 根据权利要求1所述的旋翼飞行器的旋翼,其中所述桨叶(1)包括桨根(16)、桨尖(17)以及上下相对设置的上翼面(18)和下翼面(19),所述上翼面(18)和所述下翼面(19)的一侧连接形成所述前缘(11),另一侧连接形成所述尾缘(12),所述桨叶(1)自其半径35%处延伸至所述桨尖(17)的部分具有所述翼型。
- 根据权利要求3所述的旋翼飞行器的旋翼,其中所述桨叶(1)至少为两个,至少两个所述桨叶(1)通过所述桨根(16)连接在一起,并相对于连接处的中心点位置中心对称。
- 根据权利要求11所述的旋翼飞行器的旋翼,其中,至少两个所述桨叶(1)一体成型或分体成型。
- 一种旋翼飞行器,包括根据权利要求1-11中任一项所述的旋翼飞行器的旋翼。
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US20150152733A1 (en) * | 2013-12-04 | 2015-06-04 | Sikorsky Aircraft Corporation | Boundary layer ingesting blade |
CN105752314A (zh) * | 2016-03-22 | 2016-07-13 | 西北工业大学 | 一种高空低速自然层流高升力翼型 |
CN107444611A (zh) * | 2017-08-01 | 2017-12-08 | 中国航空工业集团公司西安飞机设计研究所 | 一种高升力通用飞机翼型 |
CN107757871A (zh) * | 2017-09-20 | 2018-03-06 | 中国水利水电科学研究院 | 一种轻小型固定翼无人机用翼型 |
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CN208149614U (zh) * | 2018-04-25 | 2018-11-27 | 深圳市大疆创新科技有限公司 | 螺旋桨、动力组件及飞行器 |
CN211364914U (zh) * | 2019-12-06 | 2020-08-28 | 北京二郎神科技有限公司 | 旋翼飞行器的桨叶及旋翼飞行器 |
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US20150152733A1 (en) * | 2013-12-04 | 2015-06-04 | Sikorsky Aircraft Corporation | Boundary layer ingesting blade |
CN104354850A (zh) * | 2014-10-30 | 2015-02-18 | 中国人民解放军空军航空大学 | 一种高空长航时固定翼飞机机翼翼型 |
CN105752314A (zh) * | 2016-03-22 | 2016-07-13 | 西北工业大学 | 一种高空低速自然层流高升力翼型 |
CN107444611A (zh) * | 2017-08-01 | 2017-12-08 | 中国航空工业集团公司西安飞机设计研究所 | 一种高升力通用飞机翼型 |
CN107757871A (zh) * | 2017-09-20 | 2018-03-06 | 中国水利水电科学研究院 | 一种轻小型固定翼无人机用翼型 |
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