NZ737183B2 - A shroud for an aircraft - Google Patents
A shroud for an aircraftInfo
- Publication number
- NZ737183B2 NZ737183B2 NZ737183A NZ73718316A NZ737183B2 NZ 737183 B2 NZ737183 B2 NZ 737183B2 NZ 737183 A NZ737183 A NZ 737183A NZ 73718316 A NZ73718316 A NZ 73718316A NZ 737183 B2 NZ737183 B2 NZ 737183B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- uav
- propeller
- shroud
- noise
- noise reducing
- Prior art date
Links
- 239000011358 absorbing material Substances 0.000 claims abstract 5
- -1 Poly(methyl methacrylate) Polymers 0.000 claims 5
- 239000002121 nanofiber Substances 0.000 claims 4
- 239000002086 nanomaterial Substances 0.000 claims 4
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims 4
- 239000004926 polymethyl methacrylate Substances 0.000 claims 4
- 239000006260 foam Substances 0.000 claims 3
- 229920003189 Nylon 4,6 Polymers 0.000 claims 2
- 229920002292 Nylon 6 Polymers 0.000 claims 2
- 229920002302 Nylon 6,6 Polymers 0.000 claims 2
- 239000002131 composite material Substances 0.000 claims 2
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 claims 2
- 229920002239 polyacrylonitrile Polymers 0.000 claims 2
- 229920001610 polycaprolactone Polymers 0.000 claims 2
- 239000004632 polycaprolactone Substances 0.000 claims 2
- 239000004814 polyurethane Substances 0.000 claims 2
- 229920002451 polyvinyl alcohol Polymers 0.000 claims 2
- 230000005236 sound signal Effects 0.000 claims 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 229920012266 Poly(ether sulfone) PES Polymers 0.000 claims 1
- 239000004793 Polystyrene Substances 0.000 claims 1
- 239000012814 acoustic material Substances 0.000 claims 1
- 229910052799 carbon Inorganic materials 0.000 claims 1
- 239000000835 fiber Substances 0.000 claims 1
- 238000001914 filtration Methods 0.000 claims 1
- 239000004626 polylactic acid Substances 0.000 claims 1
- 229920005989 resin Polymers 0.000 claims 1
- 239000011347 resin Substances 0.000 claims 1
- 239000000758 substrate Substances 0.000 claims 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C2220/00—Active noise reduction systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/04—Helicopters
- B64C27/08—Helicopters with two or more rotors
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C39/00—Aircraft not otherwise provided for
- B64C39/02—Aircraft not otherwise provided for characterised by special use
- B64C39/024—Aircraft not otherwise provided for characterised by special use of the remote controlled vehicle type, i.e. RPV
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U10/00—Type of UAV
- B64U10/10—Rotorcrafts
- B64U10/13—Flying platforms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U30/00—Means for producing lift; Empennages; Arrangements thereof
- B64U30/20—Rotors; Rotor supports
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U30/00—Means for producing lift; Empennages; Arrangements thereof
- B64U30/20—Rotors; Rotor supports
- B64U30/26—Ducted or shrouded rotors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U50/00—Propulsion; Power supply
- B64U50/10—Propulsion
- B64U50/13—Propulsion using external fans or propellers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U50/00—Propulsion; Power supply
- B64U50/10—Propulsion
- B64U50/19—Propulsion using electrically powered motors
Abstract
Unmanned Aerial Vehicle (UAV) 100 comprising a shroud configured to attach to the UAV 100, and a propeller 202 configured to attach to the UAV 100, where the propeller is not part of a jet engine. The shroud is configured to at least partially surround the propeller 202, passively redirect sound waves produced by the propeller 202 in a direction above the propeller, and passively attenuate sound waves produced by the propeller in a direction below the propeller. The shroud comprises an outer layer and an inner layer comprising a noise absorbing material. The reduction of propellor noise is good for noise capture.
Claims (29)
1. An Unmanned Aerial Vehicle (UAV) comprising: a shroud configured to attach to the UAV, and 5 a propeller configured to attach to the UAV, wherein the propeller is not part of a jet engine, wherein the shroud is configured to at least partially surround the propeller, passively redirect sound waves produced by the propeller in a direction above the propeller, and passively attenuate sound waves produced by the propeller in a 10 direction below the propeller, wherein the shroud comprises an outer layer and an inner layer, wherein the inner layer comprises a noise absorbing material.
2. The UAV in claim 1 further comprising one or more audio microphones configured to sample audio signals from a target.
3. The UAV in claim 2 further comprising an electronic device to filter out noise from the target audio signal.
4. The UAV in claim 2 or 3 wherein the microphones include active filtering based on 20 a noise signal.
5. The UAV of claim 4 wherein the noise signal is provided from one or more separate microphones mounted close to the sources of unwanted noise. 25
6. The UAV of claim 5 wherein one or more microphones are mounted on arms of the UAV.
7. The UAV of claim 6 wherein one or more microphones are mounted underneath the UAV.
8. The UAV of any one of claims 2 to 7 wherein the shroud is configured to reflect 5 noise away from one or more of the microphones.
9. The UAV of any one of claims 1 to 8 further comprising one or more speakers to emit anti-noise.
10 10. The UAV of claim 9 wherein the anti-noise is generated using a modified least means squared algorithm.
11. The UAV of any one of claims 1 to 10, wherein the noise reducing shroud comprises a shroud body configured to at least partially enclose the propeller, the 15 shroud having an interior surface provided with a plurality of baffles configured to dissipate sound by reflection and refraction.
12. The UAV of claim 11 wherein the baffles are in the form of a plurality of ribs spaced apart in the direction of the axis of the propeller.
13. The UAV of claim 12 wherein the ribs decrease in size from the middle to the edges of the interior surface.
14. The UAV of claim 1 wherein a sound absorbing material is provided on a leading 25 edge of the noise reducing propeller.
15. The UAV of claim 14 wherein the noise reducing propeller includes jagged tips, microabrasions, microgrooves, microindentations, winglets and/or edge serrations.
16. The UAV of any preceding claim wherein the noise reducing shroud comprises a plurality of cross members supporting a propeller motor mounting in the centre of the shroud.
17. The UAV of any preceding claim wherein a shroud body of the noise reducing shroud is substantially aerofoil shaped.
18. The UAV of any preceding claim wherein a shroud body of the noise reducing 10 shroud is substantially composed of a composite.
19. The UAV of claim 18 wherein the shroud body is substantially composed of carbon fibre and/or nanomaterials and a resin. 15
20. The UAV of any preceding claim wherein the noise reducing shroud at least partially surrounds the noise reducing propeller.
21. The UAV of any preceding claim wherein the UAV is a multicopter UAV comprising a plurality of propellers.
22. The UAV of claim 1 wherein the noise reducing propellor is a vertical lift propeller, and wherein the noise reducing shroud comprises a shroud body configured to at least partially enclose the vertical lift propeller, and 25 a noise absorbing material on or in an inner surface of the body adjacent to and spaced from one or more tips of the vertical lift propeller.
23. The UAV of claim 22 wherein the noise absorbing material comprises a nanomaterial.
24. The UAV of claim 23 wherein the nanomaterial comprises a nanofiber.
25. The UAV of claim 24 wherein the nanofiber comprises Poly(methyl methacrylate) (PMMA), and wherein the nanofiber is layered with foam.
26. The UAV of claim 25 wherein the foam is an open-cell acoustic foam.
27. The UAV of claim 24 wherein the nanofiber comprises Polyurethane (PU).
28. The UAV of any preceding claim wherein the noise reducing shroud comprises a ridged composite acoustic material selected from the group consisting of 15 Poly(methyl methacrylate) (PMMA), Polystyrene (PS), Nylon 66 (PA66), Nylon 6 (PA6), Nylon 46 (PA46), Polycaprolactone (PCL), Poly(vinyl alcohol) (PVOH), Polyvinyl Butyral (PVB), Poly(ether sulfone) (PES), Polylactic Acid (PLA), Polyurethane (PU) and Polyacrylonitrile (PAN), and any combination thereof. 20
29. The UAV of any preceding claim wherein the noise reducing shroud comprises a noise absorbing nanomaterial that is electronspun and backed with a resilient substrate.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NZ70843115 | 2015-05-25 | ||
| NZ71898716 | 2016-04-12 | ||
| PCT/NZ2016/050087 WO2016190753A1 (en) | 2015-05-25 | 2016-05-25 | A shroud for an aircraft |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| NZ737183A NZ737183A (en) | 2024-01-26 |
| NZ737183B2 true NZ737183B2 (en) | 2024-04-30 |
Family
ID=
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