CN110775260B - Ducted fan and aircraft - Google Patents
Ducted fan and aircraft Download PDFInfo
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- CN110775260B CN110775260B CN201911216025.4A CN201911216025A CN110775260B CN 110775260 B CN110775260 B CN 110775260B CN 201911216025 A CN201911216025 A CN 201911216025A CN 110775260 B CN110775260 B CN 110775260B
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- 230000007423 decrease Effects 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 229910052799 carbon Inorganic materials 0.000 claims 1
- 230000003247 decreasing effect Effects 0.000 claims 1
- 239000000835 fiber Substances 0.000 claims 1
- 238000000926 separation method Methods 0.000 description 6
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000008676 import Effects 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/20—Rotorcraft characterised by having shrouded rotors, e.g. flying platforms
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Aviation & Aerospace Engineering (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention provides a ducted fan, which comprises a hub, blades and a ducted body. The blades are arranged on the hub and can rotate along with the hub, the duct body surrounds the blades 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 supplying air flow, 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 device can prevent the front part of the inlet of the duct body from being separated from the front part of the hub, thereby reducing the loss of thrust.
Description
Technical Field
The invention relates to the field of aircrafts, in particular to a ducted fan and an aircraft.
Background
The existing multi-rotor-wing multi-duct fan aircraft realizes the change of the gesture and the flying speed through the change of the inclination angle and the rotating speed of the blades. When the aircraft cruises and flies at a certain inclination angle, external air is sucked into the inlet of the ducted fan at a certain included angle. At present, a duct body of a duct fan is of a central symmetrical structure about a rotating shaft, air inlet conditions under different inclined angles are not considered, so that flow separation occurs at the front part of an inlet of the duct body and the front part of a hub, the flow separation at the front part of the inlet of the duct 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 a part of thrust is lost.
Disclosure of Invention
In view of the drawbacks of the prior art, an object of the present invention is to provide a ducted fan and an aircraft that prevent flow separation from occurring at the front of the inlet of the ducted body and at the front of the hub, and attenuate intake distortion, thereby reducing thrust losses.
In order to achieve the above object, in one aspect, the present invention provides a ducted fan, which includes a hub, blades, and a ducted body. The blades are arranged on the hub and can rotate along with the hub, the duct body surrounds the blades 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 supplying air flow, 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 includes an air inlet tangential to the direction of air flow and 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 air intake section and the first central axis of the duct body decreases gradually in axial direction towards the hub.
In one embodiment, the intake section is a constant diameter section.
In an embodiment, the air inlet section is a tapered section, and the second inner diameter of the air inlet section gradually decreases axially toward the outside of the air inlet section.
In an embodiment, the third inner diameter of the fan section is smaller than the second inner diameter of the air intake section.
In an embodiment, the third inner diameter of the fan section is smaller than the minimum inner diameter value of the air intake section.
In one embodiment, the bypass body is constructed of a carbon fiber material.
In another aspect, the present invention provides an aircraft, the aircraft including a fuselage and the ducted fan of the present invention, wherein an included angle between a tangent line and a transverse direction of an air inlet section of the ducted body is equal to or approximately equal to an inclination angle of a first central axis of the ducted fan relative to the fuselage.
The beneficial effects of the invention are as follows:
In the ducted fan, the blades rotate along the first central axis along the hub, and the air inlet section of the ducted fan is arranged to be of an asymmetric structure relative to the first central axis in consideration of the air inlet condition of the ducted fan under different flight dip angles, so that the front part of the inlet of the ducted body and the front part of the hub are prevented from being separated in a flowing way, the air inlet distortion is weakened, the loss of thrust is reduced, and the efficiency of the ducted fan is improved.
In the aircraft according to the invention, the angle between the tangent to the inlet of the inlet section of the duct body and the transverse direction is equal or approximately equal to the angle of inclination of the first central axis of the duct fan with respect to the fuselage. Therefore, air sucked from an air inlet of an air inlet section of the ducted fan is prevented from flowing and separating at the front part of an inlet of the ducted body and the front part of the hub, so that air flow can effectively flow to the greatest extent at a blade tip area corresponding to the front part of the inlet of the ducted body and a blade root area corresponding to the front part of the hub, air inlet distortion is weakened, thrust loss is reduced, efficiency of the ducted fan is improved, and further, the flying speed of an aircraft is improved.
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 of the ducted fan removed.
Fig. 3 is a perspective view of the ducted fan of fig. 1 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, viewed 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 reference numerals are as follows:
Third inner diameter of 1 hub 321
2-Blade L3 third central axis
3 Duct 33 air outlet section
L1 first central axis 331 first inner diameter
31 The fourth central axis L of the air inlet section L4 is axial
311 Air inlet T is transverse
312 Second inner diameter d distance
L2 second central axis beta angle
32 Fan section v air flow direction
Detailed Description
The drawings illustrate embodiments of the invention, and it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms and that the 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 examples shown in fig. 1 to 7, the ducted fan includes a hub 1, blades 2, and a ducted body 3.
The blade 2 is disposed on the hub 1 and can rotate along with the hub 1, the duct body 3 is disposed around the blade 2 and has a first central axis L1, and the hub 1 is disposed on the first central axis L1. The blades 2 rotate with the hub 1 along a first central axis L1. The ducted fan with the duct body 3 can generate larger lifting force, and the blade tips of the blades 2 are limited by the duct body 3 because the blades 2 are positioned in the duct body 3, so that impact noise can be reduced. The induced resistance is reduced and the efficiency is higher.
Referring to the examples shown in fig. 2 to 7, the duct body 3 includes an inlet section 31, a fan section 32, and an 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 this order in the axial direction L. The intake section 31 is for intake air flow, and the intake section 31 has a cross section with a second central axis L2. The fan section 32 is an equal 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 in the axial direction L. The second central axis L2 of the cross section of the intake section 31 is parallel to the first central axis L1 of the duct body 3. The third central axis L3 of the fan section 32, the fourth central axis L4 of the outlet section 33, and the first central axis L1 of the duct body 3 are collinear.
In the ducted fan according to the present invention, the blades 2 are rotated along the first central axis L1 along with the hub 1, and the intake section 31 of the ducted fan is provided in an asymmetric structure with respect to the first central axis L1 in consideration of intake conditions of the ducted fan at different flying inclinations, to prevent flow separation from the front inlet portion of the ducted body 3 and the front portion of the hub, to attenuate intake distortion, thereby reducing loss of thrust.
As shown in the example of fig. 7, the intake section 31 includes an intake port 311, the intake port 311 is tangential to the airflow direction v, and the intake section 31 is tangential to the fan section 32, and the fan section 32 is tangential to the outlet section 33. Considering the air flow direction v, the air inlet 311 is tangential to the air flow direction v to minimize intake distortion and reduce thrust loss.
Specifically, referring to the examples shown in fig. 1,2 and 7, the distance d between the second central axis L2 of the air intake section 31 and the first central axis L1 of the duct body 3 gradually decreases in the axial direction L toward the hub 1. So that the intake section 31 smoothly transitions toward the fan section 32.
Further, the intake section 31 has different embodiments.
In some embodiments, the 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 intake section 31 is a tapered section, and the second inner diameter 312 of the intake section 31 gradually decreases outward of the intake section 31 along the axial direction L. That is, the second inner diameter 312 of the intake section 31 is a varying value. Wherein the third inner diameter 321 of the fan section 32 is smaller than the minimum inner diameter value of the air intake section 31.
The third inner diameter 321 of the fan section 32 is typically 1-5 mm larger than the diameter of the blades 2, depending on the design of the ducted fan. The outer diameter of the fan section 32 depends on the thrust requirements of the ducted fan.
The aircraft according to the invention comprises a fuselage and a ducted fan according to the invention, the angle beta between the tangent of the inlet 311 of the intake 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. Thereby prevent from the air that the air inlet 311 of duct fan's air inlet section 31 takes place flow separation in duct body 3 import front portion and wheel hub front portion for the air current can the furthest effective flow in duct body 3 import front portion corresponding apex region and wheel hub front portion corresponding blade root region, weakens the distortion of intaking, reduces the loss of thrust, improves duct fan's efficiency, and then improves the flight speed of aircraft. The aircraft may be, for example, a drone.
The above detailed description describes various exemplary embodiments, but is not intended to be limited to the combinations explicitly disclosed herein. Thus, unless otherwise indicated, the various features disclosed herein may be combined together to form a number of additional combinations that are not shown for the sake of brevity.
The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (9)
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 utility model is characterized in that the duct body (3) comprises 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 allowing air 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, the fan section (32) is provided with a third central axis (L3), the air outlet section (33) is a divergent section, 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 inlet section (31) comprises an inlet (311), the inlet (311) being tangential to the air flow direction (v), and the inlet section (31) being tangential to the fan section (32), the fan section (32) being tangential to the outlet section (33).
3. Ducted fan according to claim 2, characterized in that the distance (d) between the second centre axis (L2) of the inlet section (31) and the first centre axis (L1) of the duct body (3) decreases gradually in the axial direction (L) towards the hub (1).
4. A ducted fan according to claim 3, characterized in that the air intake section (31) is an equal diameter section.
5. A ducted fan according to claim 3, characterized in that the air intake section (31) is a tapered section, the second inner diameter (312) of the air intake section (31) gradually decreasing in the axial direction (L) towards the outside of the air intake 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 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 minimum inner diameter value of the inlet section (31).
8. Ducted fan according to claim 1, characterized in that the duct body (3) is composed 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 line of the inlet (311) of the inlet section (31) of the ducted body (3) and the transverse direction (T) and the angle of inclination of the first central axis (L1) of the ducted fan with respect to the fuselage being equal or approximately equal.
Priority Applications (1)
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CN201911216025.4A CN110775260B (en) | 2019-12-02 | 2019-12-02 | Ducted fan and aircraft |
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CN201911216025.4A CN110775260B (en) | 2019-12-02 | 2019-12-02 | Ducted fan and aircraft |
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CN110775260A CN110775260A (en) | 2020-02-11 |
CN110775260B true CN110775260B (en) | 2024-06-04 |
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Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
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JP7358280B2 (en) * | 2020-03-23 | 2023-10-10 | 三菱重工業株式会社 | Ducted fans and aircraft |
CN114802733A (en) * | 2022-04-07 | 2022-07-29 | 广东汇天航空航天科技有限公司 | Ducted fan and flying device |
CN114537653A (en) * | 2022-04-24 | 2022-05-27 | 北京玮航科技有限公司 | Fixing mechanism and unmanned aerial vehicle of duct installation roof beam |
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CN102180258A (en) * | 2011-04-07 | 2011-09-14 | 龙川 | Duct aerofoil system and aerial craft applying duct aerofoil system |
CN103921931A (en) * | 2014-04-28 | 2014-07-16 | 龙川 | Duct wing system and aircraft using same |
CN105966601A (en) * | 2016-06-14 | 2016-09-28 | 西北工业大学 | Ducted fan lip inflatable air bag and flow separation control method thereof |
CN107458613A (en) * | 2015-04-17 | 2017-12-12 | 珠海磐磊智能科技有限公司 | Aircraft |
CN211364936U (en) * | 2019-12-02 | 2020-08-28 | 北京玮航科技有限公司 | Ducted fan and aircraft |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
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US20110147533A1 (en) * | 2009-12-21 | 2011-06-23 | Honeywell International Inc. | Morphing ducted fan for vertical take-off and landing vehicle |
ES2758083T3 (en) * | 2017-07-14 | 2020-05-04 | Airbus Operations Sl | Aircraft incorporating a thrust recovery system using cabin air |
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2019
- 2019-12-02 CN CN201911216025.4A patent/CN110775260B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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CN102180258A (en) * | 2011-04-07 | 2011-09-14 | 龙川 | Duct aerofoil system and aerial craft applying duct aerofoil system |
CN103921931A (en) * | 2014-04-28 | 2014-07-16 | 龙川 | Duct wing system and aircraft using same |
CN107458613A (en) * | 2015-04-17 | 2017-12-12 | 珠海磐磊智能科技有限公司 | Aircraft |
CN105966601A (en) * | 2016-06-14 | 2016-09-28 | 西北工业大学 | Ducted fan lip inflatable air bag and flow separation control method thereof |
CN211364936U (en) * | 2019-12-02 | 2020-08-28 | 北京玮航科技有限公司 | Ducted fan and aircraft |
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