阅读说明：本技术 涵道风扇和飞行器 (Ducted fan and aircraft ) 是由 李也 金宇智 张磊 周大围 于 2019-12-02 设计创作，主要内容包括：本发明提供了一种涵道风扇,其包括轮毂、叶片和涵道体。叶片设置于轮毂上且能随轮毂转动,涵道体环绕叶片设置且具有第一中心轴线,轮毂设置于第一中心轴线上；涵道体包括进气段、风扇段以及出气段；进气段、风扇段以及出气段沿轴向依次连接；进气段用于供气流进入,且进气段的横截面具有第二中心轴线,风扇段为等径段且风扇段具有第三中心轴线,出气段为渐扩段且出气段具有第四中心轴线,出气段的第一内径沿轴向向出气段外侧逐渐增大；进气段的横截面的第二中心轴线与涵道体的第一中心轴线平行,风扇段的第三中心轴线、出气段的第四中心轴线和涵道体的第一中心轴线共线。其能防止涵道体进口前部和轮毂前部发生流动分离,而减小推力的损失。(The invention provides a ducted fan which comprises a hub, blades and a ducted body. The blade is arranged on the hub and can rotate along with the hub, the duct body is arranged around the blade and is provided with a first central axis, and the hub is arranged on the first central axis; the duct body comprises an air inlet section, a fan section and an air outlet section; the air inlet section, the fan section and the air outlet section are sequentially connected along the axial direction; the air inlet section is used for allowing air flow to enter, the cross section of the air inlet section is provided with a second central axis, the fan section is an equal-diameter section and is provided with a third central axis, the air outlet section is a gradually expanding section and is provided with a fourth central axis, and the first inner diameter of the air outlet section is gradually increased towards the outer side of the air outlet section along the axial direction; the second central axis of the cross section of the air inlet section is parallel to the first central axis of the duct body, and the third central axis of the fan section, the fourth central axis of the air outlet section and the first central axis of the duct body are collinear. The flow separation between the front part of the inlet of the duct body and the front part of the hub can be prevented, and the loss of thrust is reduced.)

1. A ducted fan comprises a hub (1), blades (2) and a ducted body (3);

the blades (2) are arranged on the hub (1) and can rotate along with the hub (1), the duct body (3) is arranged around the blades (2) and is provided with a first central axis (L1), and the hub (1) is arranged on the first central axis (L1);

the ducted body (3) is characterized by comprising an air inlet section (31), a fan section (32) and an air outlet section (33); the air inlet section (31), the fan section (32) and the air outlet section (33) are sequentially connected along the axial direction (L); the air inlet section (31) is used for air flow to enter, the cross section of the air inlet section (31) is provided with a second central axis (L2), the fan section (32) is an equal-diameter section and the fan section (32) is provided with a third central axis (L3), the air outlet section (33) is a divergent section and the air outlet section (33) is provided with a fourth central axis (L4), and the first inner diameter (331) of the air outlet section (33) is gradually increased towards the outer side of the air outlet section (33) along the axial direction (L); the second central axis (L2) of the cross section of the air inlet section (31) is parallel to the first central axis (L1) of the duct body (3), and the third central axis (L3) of the fan section (32), the fourth central axis (L4) of the air outlet section (33) and the first central axis (L1) of the duct body (3) are collinear.

2. Ducted fan according to claim 1, characterized in that the air inlet section (31) comprises an air inlet (311), the air inlet (311) being tangential to the air flow direction (v), and the air inlet section (31) being tangential to the fan section (32), the fan section (32) being tangential to the air outlet section (33).

3. Ducted fan according to claim 2, characterized in that the distance (d) between the second central axis (L2) of the air inlet section (31) and the first central axis (L1) of the ducted body (3) decreases gradually in the axial direction (L) towards the hub (1).

4. Ducted fan according to claim 3, characterized in that the air inlet section (31) is a constant diameter section.

5. Ducted fan according to claim 3, characterised in that the air inlet section (31) is a tapered section, the second inner diameter (312) of the air inlet section (31) decreasing in the axial direction (L) towards the outside of the air inlet section (31).

6. Ducted fan according to claim 4, characterized in that the third inner diameter (321) of the fan section (32) is smaller than the second inner diameter (312) of the air inlet section (31).

7. Ducted fan according to claim 5, characterized in that the third inner diameter (321) of the fan section (32) is smaller than the smallest inner diameter value of the air inlet section (31).

8. Ducted fan according to claim 1, characterized in that the ducted body (3) is made of carbon fibre material.

9. An aircraft, characterized in that the aircraft comprises a fuselage and a ducted fan according to any one of claims 1-8, the angle (β) between the tangent to the air inlet (311) of the air inlet section (31) of the ducted body (3) and the transverse direction (T) being equal or approximately equal to the angle of inclination of the first central axis (L1) of the ducted fan with respect to the fuselage.

Technical Field

The invention relates to the field of aircrafts, in particular to a ducted fan and an aircraft.

Background

The existing aircraft with multiple rotors and multiple ducted fans realizes the change of the attitude and the flight speed through the change of the inclination angle and the rotating speed of the blades. When the aircraft makes a cruise flight at a certain inclination angle, external air is sucked into the inlet of the ducted fan at a certain included angle. The ducted body of the prior ducted fan is of a central symmetry structure about a rotating shaft, and air inlet conditions at different inclination angles are not considered, so that the front part of an inlet of the ducted body and the front part of a hub are subjected to flow separation, the flow separation at the front part of the inlet of the ducted body causes no effective flow in a corresponding blade tip area, the flow separation at the front part of the hub causes no effective flow in a blade root area of a corresponding blade, and part of thrust is lost.

Disclosure of Invention

In view of the drawbacks of the prior art, it is an object of the present invention to provide a ducted fan and an aircraft that prevent flow separation at the front of the inlet of the ducted body and the front of the hub, attenuating intake distortion and thus reducing the loss of thrust.

To achieve the above object, in one aspect, the present invention provides a ducted fan including a hub, blades, and a ducted body. The blade is arranged on the hub and can rotate along with the hub, the duct body is arranged around the blade and is provided with a first central axis, and the hub is arranged on the first central axis; the duct body comprises an air inlet section, a fan section and an air outlet section; the air inlet section, the fan section and the air outlet section are sequentially connected along the axial direction; the air inlet section is used for allowing air flow to enter, the cross section of the air inlet section is provided with a second central axis, the fan section is an equal-diameter section and is provided with a third central axis, the air outlet section is a gradually expanding section and is provided with a fourth central axis, and the first inner diameter of the air outlet section is gradually increased towards the outer side of the air outlet section along the axial direction; the second central axis of the cross section of the air inlet section is parallel to the first central axis of the duct body, and the third central axis of the fan section, the fourth central axis of the air outlet section and the first central axis of the duct body are collinear.

In one embodiment, the air inlet section comprises an air inlet, the air inlet is tangential to the air flow direction, the air inlet section is tangential to the fan section, and the fan section is tangential to the air outlet section.

In an embodiment, the distance between the second central axis of the inlet section and the first central axis of the bypass body decreases in the axial direction towards the hub.

In one embodiment, the air intake section is a constant diameter section.

In one embodiment, the air inlet section is a tapered section, and the second inner diameter of the air inlet section is gradually reduced towards the outer side of the air inlet section along the axial direction.

In one embodiment, the third inner diameter of the fan section is smaller than the second inner diameter of the air intake section.

In one embodiment, the third inner diameter of the fan section is less than the minimum inner diameter value of the air intake section.

In one embodiment, the stent is made of a carbon fiber material.

In another aspect, the invention provides an aircraft comprising a fuselage and the aforementioned ducted fan of the invention, the angle between the tangent to the air inlet of the air inlet section of the ducted body and the transverse direction being equal or approximately equal to the angle of inclination of the first central axis of the ducted fan with respect to the fuselage.

The invention has the following beneficial effects:

in the ducted fan according to the present invention, the blades rotate along the first central axis with the hub, and the air inlet section of the ducted fan is set to an asymmetric structure with respect to the first central axis in consideration of the air inlet condition of the ducted fan at different flight inclination angles, so as to prevent the flow separation from occurring at the front part of the inlet of the ducted body and the front part of the hub, and weaken the air inlet distortion, thereby reducing the loss of thrust and improving the efficiency of the ducted fan.

In the aircraft according to the invention, the angle between the tangent to the air inlet of the air inlet section of the ducted body and the transverse direction and the angle of inclination of the first central axis of the ducted fan with respect to the fuselage are equal or approximately equal. Thereby prevent from taking place to flow at duct body import front portion and wheel hub front portion from the inspiratory air of air inlet of the air inlet section of duct fan and separate for the air current can maximum effective flow in the blade tip region that duct body import front portion corresponds and the blade root region that wheel hub front portion corresponds, weakens the distortion of admitting air, reduces the loss of thrust, improves the efficiency of duct fan, and then improves the airspeed of aircraft.

Drawings

Fig. 1 is a perspective view of a ducted fan according to the present invention.

Fig. 2 is a perspective view of a ducted fan according to the present invention with a portion removed.

Fig. 3 is a perspective view of the ducted fan of fig. 1 viewed from another angle.

Fig. 4 is a front view of the ducted fan of fig. 3.

Fig. 5 is a perspective view of the ducted fan of fig. 1 from a further angle.

Fig. 6 is a front view of the ducted fan of fig. 5.

Fig. 7 is a sectional view taken along line a-a in fig. 6.

Wherein the reference numerals are as follows:

1 third inner diameter of hub 321

2 blade L3 third center axis

3 ducted body 33 air outlet section

L1 first center axis 331 first inner diameter

31 air intake section L4 fourth central axis Laxial

311 intake port T in the transverse direction

312 second inner diameter d distance

L2 second center axis β angle

32 fan section v airflow direction

Detailed Description

The accompanying drawings illustrate embodiments of the present invention and it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms, and therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

The ducted fan and the aircraft according to the invention are described in detail below with reference to the accompanying drawings.

Referring to the example shown in fig. 1 to 7, the ducted fan comprises a hub 1, blades 2 and a ducted body 3.

The blade 2 sets up on wheel hub 1 and can rotate along with wheel hub 1, and the duct body 3 encircles the setting of blade 2 and has first central axis L1, and wheel hub 1 sets up on first central axis L1. The blades 2 rotate with the hub 1 along the first central axis L1. The ducted fan having the ducted body 3 can generate a larger lift force, and since the blades 2 are located in the ducted body 3, the tips of the blades 2 are restricted by the ducted body 3, thereby enabling the impact noise to be reduced. The induced resistance is reduced and the efficiency is higher.

Referring to the examples shown in fig. 2 to 7, the culvert body 3 includes an air inlet section 31, a fan section 32, and an air outlet section 33. The duct body 3 is made of carbon fiber material, and has light weight and high strength. The air inlet section 31, the fan section 32, and the air outlet section 33 are connected in order along the axial direction L. The air intake section 31 is for the air flow to enter, and the cross section of the air intake section 31 has a second central axis L2. The fan section 32 is a constant diameter section and the fan section 32 has a third central axis L3. The gas outlet section 33 is a diverging section and the gas outlet section 33 has a fourth central axis L4. The first inner diameter 331 of the air outlet section 33 gradually increases toward the outside of the air outlet section 33 along the axial direction L. The second central axis L2 of the cross-section of the inlet section 31 is parallel to the first central axis L1 of the bypass body 3. The third central axis L3 of the fan section 32, the fourth central axis L4 of the air outlet section 33 and the first central axis L1 of the ductbody 3 are collinear.

In the ducted fan according to the present invention, the blades 2 are rotated along the first central axis L1 with the hub 1, and the air inlet section 31 of the ducted fan is disposed in an asymmetric structure with respect to the first central axis L1 in consideration of air inlet conditions of the ducted fan at different flight inclination angles to prevent flow separation at the inlet front portion of the ducted body 3 and the hub front portion, attenuate air inlet distortion, and reduce loss of thrust.

As shown in fig. 7, the air inlet section 31 includes an air inlet 311, the air inlet 311 is tangential to the airflow direction v, the air inlet section 31 is tangential to the fan section 32, and the fan section 32 is tangential to the air outlet section 33. Considering the airflow direction v, the air inlet 311 is tangential to the airflow direction v to reduce the intake distortion to the maximum extent and reduce the loss of thrust.

Specifically, referring to the example shown in fig. 1, 2 and 7, the distance d between the second central axis L2 of the intake section 31 and the first central axis L1 of the bypass body 3 gradually decreases in the axial direction L toward the hub 1. So that the air intake section 31 smoothly transitions towards the fan section 32.

Further, the intake section 31 has different embodiments.

In some embodiments, the air intake section 31 may be a constant diameter section. The second inner diameter 312 of the intake section 31 is constant. Wherein the third inner diameter 321 of the fan section 32 is smaller than the second inner diameter 312 of the air intake section 31.

In some embodiments, the air intake section 31 is a tapered section, and the second inner diameter 312 of the air intake section 31 gradually decreases toward the outside of the air intake section 31 along the axial direction L. That is, the second inner diameter 312 of the intake section 31 is a variable value. Wherein the third inner diameter 321 of the fan section 32 is smaller than the minimum inner diameter of the air intake section 31.

The third inner diameter 321 of the fan section 32 is dependent on the design of the ducted fan and is typically 1-5 mm larger than the diameter of the blades 2. The outer diameter of the fan section 32 depends on the thrust requirements of the ducted fan.

The included angle β between the tangent line and the transverse direction T of the air inlet 311 of the air inlet section 31 of the ducted body 3 and the first central axis L1 of the ducted fan is equal or approximately equal to the inclination angle of the first central axis L1 of the ducted fan relative to the fuselage, so that the air sucked from the air inlet 311 of the air inlet section 31 of the ducted fan is prevented from flowing and separating at the front part of the inlet of the ducted body 3 and the front part of the hub, the airflow can effectively flow at the maximum degree at the corresponding tip area and the corresponding blade root area of the front part of the hub of the inlet of the ducted body 3, the intake distortion is weakened, the loss of the thrust is reduced, the efficiency of the ducted fan is improved, and the flight speed of the aircraft is improved.

The above detailed description describes exemplary embodiments, but is not intended to limit the combinations explicitly disclosed herein. Thus, unless otherwise specified, various features disclosed herein can be combined together to form a number of additional combinations that are not shown for the sake of brevity.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.