CN109373400B - Method for acquiring noise interference device of range hood - Google Patents
Method for acquiring noise interference device of range hood Download PDFInfo
- Publication number
- CN109373400B CN109373400B CN201811420948.7A CN201811420948A CN109373400B CN 109373400 B CN109373400 B CN 109373400B CN 201811420948 A CN201811420948 A CN 201811420948A CN 109373400 B CN109373400 B CN 109373400B
- Authority
- CN
- China
- Prior art keywords
- frequency
- interference device
- noise
- noise interference
- range hood
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C15/00—Details
- F24C15/20—Removing cooking fumes
- F24C15/2021—Arrangement or mounting of control or safety systems
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/161—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general in systems with fluid flow
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Aviation & Aerospace Engineering (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Ventilation (AREA)
Abstract
The range hood is provided with a range hood main body and a noise interference device for reducing multi-frequency noise, the noise interference device is assembled on the range hood main body, the noise interference device is provided with two openings, the two openings are respectively communicated with a main air duct of the range hood main body, and the horizontal positions of the two openings are different. The invention only needs to be based on the frequency f generated by the fan bladeFObtaining a first main frequency f of the target noise reduction frequency of the noise interference device through calculation0,1Thereby obtaining L of the noise interference deviceaΔ L and C. When L isaΔ L and C, the first main frequency f of the noise interference device is obtained0,1A second main frequency f0,2First noise reduction subharmonic frequency fS1And a second noise-reduced subharmonic frequency fS2The noise interference device can offset the noise with the same frequency, thereby achieving the purpose of broadband noise reduction.
Description
Technical Field
The invention relates to the field of range hoods, in particular to a method for acquiring a noise interference device of a range hood.
Background
The hearing of people is often damaged when the users are in a high-noise environment for a long time, and the emotional problems of the users are caused when the users are in the noise environment for a long time. Along with the improvement of the life quality of people, the tolerance of people to noise is lower and lower. Therefore, the noise reduction of the range hood is more and more emphasized.
Noise reduction of a range hood in the prior art is realized mostly by an active noise reduction mode and a passive noise reduction mode. The active noise reduction mode only can act on the noise with the frequency within 1000Hz, and the noise more than 1000Hz can be processed only by a passive noise reduction technology. Passive noise reduction, however, is primarily achieved by wrapping the noise source or duct with sound absorbing cotton. But has several disadvantages as follows: firstly, the air pressure loss is too large, noise and fluid need to penetrate through the sound absorption cotton, sound energy is lost by friction, the noise reduction effect is achieved, and meanwhile, the air performance is reduced. Secondly, it is difficult to select proper sound-absorbing cotton, and few supply factories can provide data of sound absorption rate of sound-absorbing cotton under different frequencies, so manufacturers of range hoods can only find out proper type or thickness of sound-absorbing cotton in continuous trial and error. Thirdly, the noise reduction frequency of the sound absorption cotton is uncontrollable, the common sound absorption cotton cannot achieve the maximum noise reduction effect under the specified narrow frequency, and different strategies cannot be mutually matched in design to effectively reduce noise.
Therefore, aiming at the defects in the prior art, the method for acquiring the noise interference device of the range hood is necessary to solve the defects in the prior art.
Disclosure of Invention
The invention aims to provide a method for acquiring a noise interference device of a range hood, which avoids the defects of the prior art. The noise interference device capable of reducing specific multi-frequency noise is obtained by the method for obtaining the noise interference device of the range hood.
The above object of the present invention is achieved by the following technical measures:
the range hood is provided with a range hood main body and a noise interference device for reducing multi-frequency noise, and the noise interference device is assembled on the range hood main body.
Preferably, the noise interference device is provided with two openings which are respectively communicated with the main air duct of the cigarette machine main body and have different horizontal positions.
The acquisition method comprises the following steps:
step one, obtaining the fan blade generation frequency f of the range hoodF;
Step two, generating frequency f according to the fan blade obtained in the step oneFDetermining a first main frequency f of a target noise reduction frequency of a noise interference device0,1;
Step three, according to the first main frequency f obtained in the step two0,1Determining the length L of the noise interference deviceaAnd the shortest distance Δ L of the two openings;
step four, according to the step threeObtained LaAnd Δ L, determining the noise interference device diameter C.
Preferably, the first step is specifically that the frequency f generated by the fan blade of the range hoodFObtained by the method of the formula (I),
fFβ Ψ ω formula (i),
where β is 1/60, Ψ is the number of blades of the fan blade, and ω is the rotational speed of the main blade.
Preferably, the second noise step is implemented by generating the frequency f of the fan blade according to the first noise stepFObtaining a first main frequency f of a target noise reduction frequency of the noise interference device by a formula (II)0,1,
f0,1=dfFThe compound of the formula (II),
where d is a noise reduction weight factor and d is a positive number.
Preferably, in the third step, L is determined by formula (III)aAnd the value of al is calculated,
wherein t is the sound velocity, N is the subharmonic frequency multiple, and N is obtained by the formula (IV),
n ═ 2p +1)/2 formula (iv),
wherein p is a multiple weighting factor and p is 0 or any positive integer.
Preferably, L is as defined abovea>ΔL。
Preferably, the fourth step is specifically the L obtained according to the third stepaAnd Δ L, C is obtained by the formula (V),
preferably, the noise interference device is provided in plurality.
Preferably, C is a single value or a plurality of values.
Preferably, L is as defined aboveaEither a single value or multiple values.
Preferably, Δ L is a single value or a plurality of values.
The invention discloses an acquisition method of a noise interference device of a range hood, the range hood is provided with a range hood main body and the noise interference device for reducing multi-frequency noise, the noise interference device is assembled on the range hood main body, the noise interference device is provided with two openings, the two openings are respectively communicated with a main air duct of the range hood main body, and the horizontal positions of the two openings are different. The invention only needs to be based on the frequency f generated by the fan bladeFObtaining a first main frequency f of the target noise reduction frequency of the noise interference device through calculation0,1Thereby obtaining L of the noise interference deviceaΔ L and C. When L isaΔ L and C, the first main frequency f of the noise interference device is obtained0,1A second main frequency f0,2First noise reduction subharmonic frequency fS1And a second noise-reduced subharmonic frequency fS2Thereby achieving the purpose of broadband noise reduction. Meanwhile, the range hood can be provided with a plurality of noise interference devices, C, L of the noise interference devicesaAnd the values of the delta L and the delta L can be the same or different, and the noise interference device can offset the noise with the same frequency, so that the noise interference device can reduce the wide-frequency noise waves generated by the range hood and achieve the maximum broadband noise reduction effect.
Drawings
The invention is further illustrated by means of the attached drawings, the content of which is not in any way limiting.
Fig. 1 is a flowchart of an acquisition method of a noise interference device of a range hood according to the present invention.
Fig. 2 is a schematic structural view of the noise interference device and the main duct according to embodiment 1.
Fig. 3 is a schematic cross-sectional view of fig. 2.
FIG. 4 shows the length L of the noise interference deviceaSchematic representation of (a).
Fig. 5 is a schematic diagram of the shortest distance Δ L of two openings.
FIG. 6 is a schematic structural diagram of a noise interference device and a main air duct in embodiment 2.
In fig. 1 to 6, the following components are included:
noise interferes with the device 1 and the main duct 2.
Detailed Description
The technical solution of the present invention is further illustrated by the following examples.
Example 1.
A method for acquiring a noise interference device of a range hood is provided, the range hood is provided with a range hood main body and the noise interference device 1 for reducing multi-frequency noise, and the noise interference device 1 is assembled on the range hood main body.
As shown in FIGS. 2 to 5, the noise interference device 1 is provided with two openings which are respectively communicated with the main duct 2 of the cigarette maker main body and have different horizontal positions as shown by K in FIG. 31K of2As shown.
The acquisition method comprises the following steps, as shown in fig. 1:
step one, acquiring the generation frequency f of a fan blade of a range hoodF;
Step two, generating frequency f according to the fan blade obtained in the step oneFObtaining a first main frequency f of a target noise reduction frequency of the noise interference device 10,1;
Step three, according to the first main frequency f obtained in the step two0,1Determining the length L of the noise interference device 1aAnd the shortest distance Δ L of the two openings;
step four, obtaining L according to the step threeaAnd Δ L, determining the diameter C of the noise interference device 1.
Wherein the first step is specifically that the frequency f generated by the fan blade of the range hoodFObtained by the method of the formula (I),
fFβ Ψ ω formula (i),
where β is 1/60, Ψ is the number of blades of the fan blade, and ω is the rotational speed of the main blade.
Wherein the second step is specifically that the fan blade generation frequency f obtained according to the first stepFObtaining a first main frequency f of a target noise reduction frequency of the noise interference device 1 by formula (II)0,1,
f0,1=dfFThe compound of the formula (II),
where d is a noise reduction weighting factor, and d is a positive number, d can be any positive number such as 0.1, 5, 10, 21, 10000, etc.
Wherein the third step is to determine L by the formula (III)aAnd the value of al is calculated,
wherein t is the sound velocity, N is the subharmonic frequency multiple, and N is obtained by the formula (IV),
n ═ 2p +1)/2 formula (iv),
wherein p is a multiple weighting factor, and p is 0 or any positive integer, and p can be 0, 1, 2,. eta.10000,. eta.infinity.
Wherein L isa>ΔL。
It should be noted that, the present invention can set a specific L according to the actual requirementaOr Δ L, and then another value range can be obtained as long as L is satisfiedaMore than Delta L.
Wherein the fourth step is specifically that L obtained according to the third stepaAnd Δ L, C is obtained by the formula (V),
the invention can be based on L of step threeaAnd the value of the sum delta L is calculated by the formula (VI) to obtain a second main frequency f of the target noise reduction frequency of the noise interference device 10,2,
Where k is the ratio of the multiples of the sub-harmonic frequency, and k is 2/3.
The invention can also be based on the first main frequency f obtained in step two0,1Obtaining a first noise-reduction subharmonic frequency f of a target noise-reduction frequency of the noise interference device 1 by the formula (VII)s1,
fs1=[3f0,1,5f0,1,...........,xf0,1]The compound of the formula (VII),
wherein x is more than or equal to 2m +1, m is 1, 2, 3.
The invention can also obtain the second main frequency f according to the fifth step0,2The second noise-reduction subharmonic frequency f of the target noise-reduction frequency of the noise interference device 1 is obtained by the formula (VIII)s2,
fs2=[2f0,2,3f0,2,...........,yf0,2]In the formula (VIII),
wherein y is more than or equal to 2.
It should be noted that the noise reduction frequency of the same noise interference device 1 is the first main frequency f0,1A second main frequency f0,2First noise reduction subharmonic frequency fS1And a second noise-reduced subharmonic frequency fS2. The noise interference device 1 of the invention therefore only needs to be based on the frequency f generated by the fan bladesFThe first main frequency f of the target noise reduction frequency of the noise interference device 1 is obtained by calculation0,1Thereby obtaining L of the noise interference device 1aΔ L and C. When L isaΔ L and C, a first main frequency f of the noise interference device 1 is obtained0,1A second main frequency f0,2First noise reduction subharmonic frequency fS1And a second noise-reduced subharmonic frequency fS2Because the noise interference device can offset the noise with the same frequency as the frequency, the noise interference device can reduce the wide-frequency noise waves generated by the range hood and achieve the maximum broadband noise reduction effect.
The noise wave of the range hood is mainly based on the frequency f generated by the fan bladeFThe frequency f is generated when the fan blade is operatedFThe inside of the range hood can generate resonance to form wide-frequency noise waves.
The noise reduction principle of the noise interference device 1 of the present invention is as follows: the noise interference device 1(Herschel-Quincke tube) achieves a sound reduction effect based on resonance and interference between sound waves. Because the noise interference device 1 has a plurality of resonance frequencies: first main frequency f0,1A second main frequency f0,2First noise reduction subharmonic frequency fs1And a second noise-reduced subharmonic frequency fs2. Wide-frequency noise waves generated by the range hood are transmitted in the main air duct 2, and when encountering a noise interference device, the wide-frequency noise waves are divided into a first wide-frequency noise wave and a second wide-frequency noise wave, and the first wide-frequency noise wave is continuously transmitted in the main air duct 2; the second path of wide-frequency noise wave enters the noise interference device 1, resonates with the noise interference device 1, and exits from one of the openings of the noise interference device and enters the main air duct 2.
When the second channel width frequency noise wave has the first main frequency f0,1A second main frequency f0,2First noise reduction subharmonic frequency fs1And a second noise-reduced subharmonic frequency fs2And at the same or similar frequency, the second path of wide-frequency noise wave enters the noise interference device 1 and resonates with the noise interference device 1, and exits from one of the openings of the noise interference device 1 and enters the main air duct. After being converged into the main air duct 2, a first path of wide-frequency noise wave transmitted from the noise interference device 1 has a phase difference with a second path of wide-frequency noise wave transmitted by the main air duct 2, the first path of wide-frequency noise wave and the second path of wide-frequency noise wave interfere to form an interference wide-frequency noise wave, and the amplitude of the interference wide-frequency noise wave relative to the wide-frequency noise wave is weakened and the noise is reduced.
The invention carries out actual measurement of noise spectrum on the range hood with the noise interference device 1 obtained after calculation, for example, a noise collector is used for carrying out noise signal acquisition around the range hood, and the acquired real-time signal (time domain) is converted from the time domain to the frequency domain after fast Fourier conversion. A signal of the frequency spectrum is obtained in the frequency domain in order to decide whether the noise interference device 1 is to denoise all or a particular noise frequency. If the decibel value of a single frequency or a plurality of frequencies in the frequency spectrum is higher than 40dB, it indicates that the noise frequency is not eliminated or the elimination effect is not good, so that it is possible to increase a plurality of noise interference devices 1 or adjust L of the noise interference devices 1aAl and C are above the 40dB specific noise frequency for these decibel values.
The noise interference of the range hoodThe device acquisition method comprises four steps. The invention only needs to be based on the frequency f generated by the fan bladeFThe first main frequency f of the target noise reduction frequency of the noise interference device 1 is obtained by calculation0,1Thereby obtaining L of the noise interference deviceaΔ L and C. When L isaΔ L and C, a first main frequency f of the noise interference device 1 is obtained0,1A second main frequency f0,2First noise reduction subharmonic frequency fS1And a second noise-reduced subharmonic frequency fS2Because the noise interference device can offset the noise with the same frequency as the frequency, the noise interference device can reduce the wide-frequency noise waves generated by the range hood and achieve the maximum broadband noise reduction effect.
Example 2.
A method for acquiring a noise interference device of a range hood is shown in figure 6, and other characteristics are the same as those of embodiment 1, except that: the noise interference device 1 of the range hood of the present invention can also be provided in a plurality of numbers, such as 2, 4, 10, 500 or 10000, etc., and the specific noise interference device 1 is determined according to the actual situation. The embodiment is specifically 4.
The range hood of the present invention may have a single value or a plurality of values for C of the plurality of noise interference devices 1. L isaCan be a single value or multiple values, specifically LaThe number of the sum Δ L values depends on the actual situation. Δ L may be a single value or a plurality of values. L of the present embodimentaAnd Δ L have a plurality of different values, respectively.
In addition, the compound is represented by the formula (III)It can be seen that for the same f0,1,LaAnd the values of al are not exclusive. That is to say for the toolHaving the same first main frequency f0,1May also be different as long as L isaAnd Δ L satisfies the formula (III).
When L isaAnd Δ L having a plurality of different values, a first main frequency f of the plurality of noise interference devices 10,1Possibly different, when the first main frequency f0,1At different times, the second main frequency f0,2First noise reduction subharmonic frequency fS1And a second noise-reduced subharmonic frequency fS2And also different. The frequency range of the plurality of noise interference devices 1 is wider than that of embodiment 1, thereby achieving better broadband noise reduction.
Example 3.
The other characteristics of the method for acquiring the noise interference device of the range hood are the same as those of the embodiment 1, and the difference is that: l of the present embodimentaSpecifically 10cm,. DELTA.L specifically 3cm, and C0.18 cm.
Compared with embodiment 1, L of the noise interference device 1 of the present embodimentaAnd Δ L, C, the range hood with the noise interference device 1 has the advantage of good noise reduction.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (9)
1. A method for acquiring a noise interference device of a range hood is characterized by comprising the following steps: the range hood is provided with a range hood main body and a noise interference device for reducing multi-frequency noise, wherein the noise interference device is assembled on the range hood main body;
the noise interference device is provided with two openings which are respectively communicated with a main air duct of the cigarette machine main body and have different horizontal positions;
the acquisition method comprises the following steps:
step one, obtaining the fan blade generation frequency f of the range hoodF;
Step two, generating frequency f according to the fan blade obtained in the step oneFDetermining a first main frequency f of a target noise reduction frequency of a noise interference device0,1;
Step three, according to the first main frequency f obtained in the step two0,1And then, according to the actual requirement, firstly setting the length L of a specific noise interference deviceaOr the shortest distance Δ L of two openings, and then determining the corresponding Δ L or LaAs a result, L needs to be satisfieda>ΔL;
Step four, obtaining L according to the step threeaAnd Δ L, determining the diameter C of the noise interference device.
2. The acquisition method of the noise interference device of the range hood according to claim 1, characterized in that: in the first step, the frequency f generated by the fan blade of the range hoodFObtained by the method of the formula (I),
fFβ Ψ ω formula (i),
where β is 1/60, Ψ is the number of blades of the fan blade, and ω is the rotational speed of the main blade.
3. The acquisition method of the noise interference device of the range hood according to claim 1, characterized in that: the second step is specifically that the fan blade generation frequency f obtained according to the first stepFObtaining a first main frequency f of a target noise reduction frequency of the noise interference device by a formula (II)0,1,
f0,1=dfFThe compound of the formula (II),
where d is a noise reduction weight factor and d is a positive number.
4. The acquisition method of the noise interference device of the range hood according to claim 1, characterized in that: the third step is to determine L by the formula (III)aAnd the value of al is calculated,
wherein t is the sound velocity, N is the subharmonic frequency multiple, and N is obtained by the formula (IV),
n ═ 2p +1)/2 formula (iv),
wherein p is a multiple weighting factor and p is 0 or any positive integer.
6. the acquisition method of the noise interference device of the range hood according to claim 1, characterized in that: the noise interference device is provided in plurality.
7. The acquisition method of the noise interference device of the range hood according to claim 5, characterized in that: the C is a single value or a plurality of values.
8. The acquisition method of the noise interference device of the range hood according to claim 5, characterized in that: said LaEither a single value or multiple values.
9. The acquisition method of the noise interference device of the range hood according to claim 5, characterized in that: the Δ L is a single value or a plurality of values.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811420948.7A CN109373400B (en) | 2018-11-27 | 2018-11-27 | Method for acquiring noise interference device of range hood |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811420948.7A CN109373400B (en) | 2018-11-27 | 2018-11-27 | Method for acquiring noise interference device of range hood |
Publications (2)
Publication Number | Publication Date |
---|---|
CN109373400A CN109373400A (en) | 2019-02-22 |
CN109373400B true CN109373400B (en) | 2020-08-14 |
Family
ID=65383997
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201811420948.7A Active CN109373400B (en) | 2018-11-27 | 2018-11-27 | Method for acquiring noise interference device of range hood |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN109373400B (en) |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10307588A (en) * | 1997-05-07 | 1998-11-17 | Tsubakimoto Chain Co | Sound insulating structure and sound insulating wall for casing panel |
US7395898B2 (en) * | 2004-03-05 | 2008-07-08 | Rsm Technologies Limited | Sound attenuating structures |
CN103035234B (en) * | 2011-09-28 | 2016-08-03 | 比亚迪股份有限公司 | Active noise reducing device and method and the noise control system for smoke exhaust ventilator |
DE102013200458A1 (en) * | 2013-01-15 | 2014-07-17 | Robert Bosch Gmbh | System for environment sensors |
CN104422109B (en) * | 2013-08-26 | 2018-02-06 | 广东美的暖通设备有限公司 | For air-conditioning silencer and there is its air-conditioning |
CN104318919B (en) * | 2014-10-22 | 2020-04-21 | 上海斐讯数据通信技术有限公司 | Environment noise elimination method and system and mobile terminal |
CN107084469B (en) * | 2017-06-09 | 2022-08-02 | 陈宇翔 | Double-air-duct noiseless exhaust device based on sound wave interference |
CN107204181A (en) * | 2017-07-26 | 2017-09-26 | 安徽理工大学 | A kind of resonant labyrinth noise reduction method and set composite |
-
2018
- 2018-11-27 CN CN201811420948.7A patent/CN109373400B/en active Active
Also Published As
Publication number | Publication date |
---|---|
CN109373400A (en) | 2019-02-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN101400007A (en) | Active noise eliminating earphone and noise eliminating method thereof | |
WO2016177203A1 (en) | Pipeline denoising system and method | |
CN108954443A (en) | A kind of kitchen ventilator and noise-reduction method of the active and passive denoising device of band | |
CN115081109A (en) | Hypersonic velocity boundary layer transition suppression method based on acoustic hypersurface and micro blow-suction | |
Wang et al. | A study of active tonal noise control for a small axial flow fan | |
CN112303033A (en) | Sleeve type Helmholtz resonance silencer with small length-diameter ratio and silencing method thereof | |
CN113793587B (en) | Noise reduction method based on vortex array | |
CN109373400B (en) | Method for acquiring noise interference device of range hood | |
Paruchuri et al. | On the superior performance of leading edge slits over serrations for the reduction of aerofoil interaction noise | |
CN108731081A (en) | A kind of kitchen ventilator with noise filtering function exhausting component | |
CN109373399B (en) | Broadband noise reduction method for range hood with noise interference device | |
JP2015158542A (en) | Noise reduction method in closed space, and noise reduction system | |
CN109961773B (en) | Active noise reduction method for rotary mechanical order noise | |
TW201322782A (en) | Implementation of active noise cancellation of exhaust hood using phase compensation technology | |
US20210402118A1 (en) | Driving device for providing assisted ventilation | |
CN114966635A (en) | Moving object line spectrum enhancement method based on long-time coherent accumulation | |
Wang et al. | Noise source analysis and control of two axial-flow cooling fans in series | |
Salikuddin | Acoustic behavior of orifice plates and perforated plates with reference to low-frequency sound absorption | |
CN206655759U (en) | Muffler, engine and the vehicle of engine aspirating system | |
CN206973651U (en) | A kind of lampblack absorber of active active noise reduction | |
Sutliff et al. | Foam-metal liner attenuation of low-speed fan noise | |
CN106992066B (en) | A kind of active-mode active denoising device | |
CN112331174B (en) | Range hood noise reduction method and range hood | |
CN111862926A (en) | Narrow-band active noise reduction algorithm of air-assisted sprayer | |
Teoh et al. | Suppression of Flow-Induced Noise of a Canister Vacuum Cleaner |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |