CN107180132B - Structural parameter design method for inhibiting nonlinear effect of micro-perforated plate - Google Patents

Structural parameter design method for inhibiting nonlinear effect of micro-perforated plate Download PDF

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CN107180132B
CN107180132B CN201710346441.0A CN201710346441A CN107180132B CN 107180132 B CN107180132 B CN 107180132B CN 201710346441 A CN201710346441 A CN 201710346441A CN 107180132 B CN107180132 B CN 107180132B
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钱玉洁
张�杰
孙宁
姚潇
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Changzhou Campus of Hohai University
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Abstract

The invention discloses a structural parameter design method for inhibiting the nonlinear effect of a micro-perforated plate, which comprises the following steps: the method comprises the following steps: analyzing the frequency spectrum and the sound pressure level of the high sound intensity noise field, and determining a limiting condition parameter and a parameter to be designed according to the frequency domain distribution condition of noise energy; step two: selecting a group of { d, t/d } parameters; step three: calculating a corresponding perforation rate sigma; step four: based on the parameter combination { d, t/d, σ } and the known parameter f0And drawing the acoustic impedance Z of the micro-perforated plate structure along with the incident sound pressure level P through numerical simulationiA profile of change; step five: and observing the relation curve of the acoustic impedance changing along with the incident sound pressure level in the third step to obtain the conversion sound pressure level of the nonlinear acoustic impedance starting to act. The invention effectively restrains the nonlinear effect of the sound absorption structure of the micro-perforated plate under high sound intensity, so that the sound absorption structure has good linear sound absorption performance within a given sound pressure level range, and the sound pressure level range which can be effectively applied by the sound absorption structure of the micro-perforated plate is greatly expanded.

Description

Structural parameter design method for inhibiting nonlinear effect of micro-perforated plate
Technical Field
The invention relates to a structural parameter design method for inhibiting the nonlinear effect of a micro-perforated plate, belonging to the technical field of sound absorption and noise reduction.
Background
The sound absorption structure of the micro-perforated plate has the advantages of cleanness, light weight, moisture resistance, high temperature resistance, plate diversity and the like, and is known as the most attractive green environment-friendly sound absorption material in the 21 st century. The sound absorption structure of the micro perforated plate is provided in 1975 by the teaching of national acoustics Tadouma \29495, and through decades of development, a theoretical model of acoustic impedance of the micro perforated plate structure under the linear condition of lower sound pressure level (the sound pressure level SPL is generally less than 100dB and even less) and a related acoustic design theory are quite perfect, however, in the application environment with high-intensity sound field, such as an aircraft engine, a missile launching well and the like, the acoustic impedance of the micro perforated plate structure depends on the incident sound pressure level and shows strong nonlinear effect, at the moment, the acoustic impedance comprises two parts, one part is linear acoustic impedance, and the other part is nonlinear acoustic impedance caused by the nonlinear effect. The linear acoustic impedance is independent of the sound pressure level, and the acoustic impedance can be accurately calculated by applying a mature acoustic impedance calculation formula under a linear condition, so that the key for establishing an accurate acoustic impedance model of the micro-perforated plate structure under high sound intensity is the accurate acquisition of the nonlinear acoustic impedance. For this reason, various researchers have been making diligent efforts, but unfortunately, until now, the nonlinear acoustic impedance models for microperforated plate structures have been largely semi-empirical and have not been known to be accurately calculated and predicted by a well-established model or method. The main reason for this is that the nonlinear sound absorption mechanism is the acoustic vortex energy conversion caused by the hole-end jet flow and vortex shedding, and the complexity of the physical process of acoustic vortex energy conversion has blocked the possibility of obtaining an accurate acoustic impedance theoretical model at high sound intensity. The nonlinear effect not only makes the perfect acoustic impedance theoretical model and acoustic design theory of the micro-perforated plate structure no longer suitable under the linear condition, but also causes the problems that the sound absorption performance is reduced, the accurate acoustic impedance theoretical model is difficult to establish and the like. This is because the microperforated panel itself already provides sufficient linear acoustic resistance, which, if combined with non-linear acoustic resistance, would otherwise result in reduced sound absorption. Although many scholars at home and abroad can extend the application of the micro-perforated plate structure to a high sound pressure level (for example, a common perforated plate with the aperture larger than 1mm is adopted) by reducing the linear sound resistance and utilizing the nonlinear sound resistance to play a leading role, the method does not fundamentally solve the problem that the sound pressure level range applicable to the micro-perforated plate structure is limited by the nonlinear effect. Because the nonlinear acoustic impedance varies with the magnitude of the sound pressure level, it is difficult to universally design for different sound pressure levels. These all limit the effective use of nonlinear effects.
Studies have shown that the acoustic impedance of a microperforated plate structure undergoes a transition from a linear phase to a non-linear phase as the sound pressure level increases, and that at the transition corresponds to a particular sound pressure level, which may be referred to as the critical sound pressure level, which is the critical condition for the onset of action of the non-linear acoustic impedance. If the effective inhibition of the nonlinear effect can be realized, namely the critical sound pressure level is increased, so that the micro-perforated plate has linear sound absorption capacity below the critical sound pressure level, the sound pressure level range effectively applied by the micro-perforated plate can be widened to high sound intensity, and the sound absorption characteristic can be accurately predicted and designed as required by applying the perfect acoustic design theory under the linear condition. The method is essentially different from the existing method for reducing the linear acoustic resistance as much as possible and expanding the application of the method to high sound intensity through nonlinear acoustic impedance, and is not reported yet.
Disclosure of Invention
The purpose is as follows: aiming at the problem that the application of the sound absorption structure of the micro-perforated plate is limited by the nonlinear effect under high sound intensity, the invention provides a method for inhibiting the nonlinear effect of the micro-perforated plate through structural parameter design, so that the sound absorption structure of the micro-perforated plate has good linear sound absorption performance within a given sound pressure level range by effectively inhibiting the nonlinear effect of the sound absorption structure of the micro-perforated plate under high sound intensity, and the sound pressure level range which can be effectively applied by the sound absorption structure of the micro-perforated plate is greatly widened.
The technical scheme is as follows: a structural parameter design method for inhibiting the nonlinear effect of a micro-perforated plate comprises the following steps:
the method comprises the following steps: carrying out spectrum and sound pressure level analysis on a high sound intensity noise field, determining a linear sound pressure level range and a maximum noise reduction frequency point of expected work of a micro-perforated plate according to the frequency domain distribution condition of noise energy, and further determining limiting condition parameters and parameters to be designed, wherein the known parameters comprise:
P0: the maximum sound pressure level of the operating environment of the micro-perforated plate is dB;
f0: the maximum noise reduction frequency point of the micro-perforated plate, namely the resonance frequency, the noise at the frequency is maximum and is measured in Hz;
parameters to be designed:
d, the perforation diameter of the micro-perforated plate is m;
t/d is a dimensionless parameter which represents the length-diameter ratio of the microperforated plate, and t is the plate thickness and the unit is m;
σ: the perforation rate of the micro-perforated plate is a dimensionless parameter;
step two: selecting a set of { d, t/d } parameters, d being less than 0.2 x 10-3m, t/d is more than 1.
Step three: and (3) calculating the corresponding puncturing rate sigma by substituting the equation (1) according to the { d, t/d } parameter selected in the step two:
Figure BDA0001296602430000031
wherein the content of the first and second substances,
Figure BDA0001296602430000032
dimensionless variables, from which the parameter combinations { d, t/d, σ } are derived
Step four: according to the parameter combination { d, t/d, sigma } in step three and the known parameter f0And drawing the acoustic impedance Z of the micro-perforated plate structure along with the incident sound pressure level P through numerical simulationiCurve of change, wherein PiIs incident sound pressure PiiConversion to the expression in dB, acoustic impedance Z and incident sound pressure P under high sound intensityiiThe basic relationship of (A) is:
Figure BDA0001296602430000033
wherein the content of the first and second substances,
Figure BDA0001296602430000034
X/ρ0c0＝ωH/σc0-cot(ωLc/c0) (4)
in the above equations (2) to (4), Z is the acoustic impedance of the microperforated plate structure in MKS rayls; RL is the linear acoustic resistance, given in MKS rayls; x is antinoise, in MKS rayls; piiIs incident sound pressure in Pa; rho0Is the air density in kg/m3；c0Is the speed of sound in air, in m; ω -2 π f is the angular frequency in rad/s, and v is the kinematic viscosity coefficient; unit is m2/s，CDIs a flow coefficient, and the specific expression is as follows:
Figure BDA0001296602430000041
wherein the content of the first and second substances,
Figure BDA0001296602430000042
Figure BDA0001296602430000043
Figure BDA0001296602430000044
Figure BDA0001296602430000045
Figure BDA0001296602430000046
Figure BDA0001296602430000047
Figure BDA0001296602430000048
Figure BDA0001296602430000049
Figure BDA00012966024300000410
Figure BDA00012966024300000411
Figure BDA00012966024300000412
Figure BDA00012966024300000413
Figure BDA00012966024300000414
Figure BDA00012966024300000415
Figure BDA0001296602430000051
in the above formulae (5) to (20), PpKHas the unit of Pa, deThe unit of (a) is m, and other parameters are dimensionless parameters.
KssIs a static viscous loss parameter, which is a dimensionless parameter:
Kss＝13+10.23(t/d)-1.44(21)
Kacis an acoustic viscous loss parameter, which is a dimensionless parameter:
Kac＝3+2.32(t/d)-1(22)
h is the inertial length parameter:
Figure BDA0001296602430000052
Figure BDA0001296602430000053
κH＝13.06[1-exp(-64.9(t/d)4.365)](25)
Figure BDA0001296602430000054
Figure BDA0001296602430000055
aH＝0.725(t/d)-1.227,bH＝1.02(t/d)-1.411,mH＝3.42exp(-0.117(t/d)) (28)
in the above formulae (23) to (28)H and HresThe unit of (1) is m, and the other newly related parameters are dimensionless parameters;
at the time of resonance:
Lc＝(c0/2πf0)arccot(2πf0H/σc0) (29)；
wherein L iscIs the cavity depth in m;
step five: observing the acoustic impedance Z of the micro-perforated plate structure in the fourth step along with the incident sound pressure level PiThe curve of variation, the transition sound pressure level at which the non-linear acoustic impedance comes into play, i.e. the critical sound pressure level P, is obtainedtIn dB, if P0≤PtShowing that the selected design parameters satisfy the suppression of the nonlinear effects of the microperforated plate structure if P0>PtAnd (4) explaining that the selected design parameters are not satisfied, reducing the aperture d or increasing t/d, and then returning to the step three until structural parameters capable of realizing the nonlinear effect are obtained.
Has the advantages that: the invention adopts a method for inhibiting the nonlinear effect of the micro-perforated plate through the structural parameter design, overcomes the limitation of the nonlinear effect on the application of the sound absorption structure of the micro-perforated plate under high sound intensity, and determines the maximum sound pressure level P according to the actual noise condition0And a maximum noise reduction frequency point f0The structural parameters of the micro-perforated plate for effectively inhibiting the nonlinear effect can be designed, so that the micro-perforated plate has good linear sound absorption performance under high sound intensity. Compared with the prior art which utilizes the nonlinear effect to generate nonlinear acoustic impedance to absorb sound and reduce noise, the sound absorption performance of the invention does not depend on the nonlinear acoustic impedance, thus being not influenced by incident sound pressure level, having wider sound absorption frequency band and wider applicable sound pressure level range.
Drawings
FIG. 1 is a parameter diagram of a microperforated panel sound absorbing structure;
FIG. 2 is a detailed flow chart of a method for designing structural parameters for suppressing the nonlinear effect of a micro-perforated plate;
FIG. 3 is a graph of acoustic impedance as a function of incident sound pressure level for example 1;
FIG. 4 is a graph of acoustic impedance versus incident sound pressure level for the combination of parameters set 1 in example 2;
FIG. 5 is a graph of acoustic impedance versus incident sound pressure level for the set 2 combination of parameters in example 2;
FIG. 6 is a graph of acoustic impedance versus incident sound pressure level for the combination of parameters set 3 in example 2;
Detailed Description
In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
As shown in fig. 1 to 6, a method for designing structural parameters for suppressing the nonlinear effect of a micro-perforated plate includes the following steps:
the method comprises the following steps: carrying out spectrum and sound pressure level analysis on a high sound intensity noise field, determining a linear sound pressure level range and a maximum noise reduction frequency point of expected work of a micro-perforated plate according to the frequency domain distribution condition of noise energy, and further determining limiting condition parameters and parameters to be designed, wherein the known parameters comprise:
P0: the maximum sound pressure level of the working environment of the micro-perforated plate is realized by the design of structural parameters as long as the sound pressure level P is satisfiedt<P0In the process, the linear response of the micro-perforated plate plays a leading role, the nonlinear effect can be ignored, and the unit is dB;
f0: the maximum noise reduction frequency point of the micro-perforated plate, namely the resonance frequency, the noise at the frequency is maximum and is measured in Hz;
parameters to be designed:
d, the perforation diameter of the micro-perforated plate is m;
t/d is a dimensionless parameter which represents the length-diameter ratio of the microperforated plate, and t is the plate thickness and the unit is m;
σ: the perforation rate of the micro-perforated plate is a dimensionless parameter;
step two: selecting a set of { d, t/d } parameters, d being less than 0.2 x 10-3m, t/d is more than 1.
Step three: and (3) calculating the corresponding puncturing rate sigma by substituting the equation (1) according to the { d, t/d } parameter selected in the step two:
Figure BDA0001296602430000071
wherein the content of the first and second substances,
Figure BDA0001296602430000081
dimensionless variables, from which the parameter combinations { d, t/d, σ } are derived
Step four: according to the parameter combination { d, t/d, sigma } in step three and the known parameter f0And drawing the acoustic impedance Z of the micro-perforated plate structure along with the incident sound pressure level P through numerical simulationiCurve of change, wherein PiIs incident sound pressure PiiConversion to the expression in dB, acoustic impedance Z and incident sound pressure P under high sound intensityiiThe basic relationship of (A) is:
Figure BDA0001296602430000082
wherein the content of the first and second substances,
Figure BDA0001296602430000083
X/ρ0c0＝ωH/σc0-cot(ωLc/c0) (4)
in the above equations (2) to (4), Z is the acoustic impedance of the microperforated plate structure in MKS rayls; RL is the linear acoustic resistance, given in MKS rayls; x is antinoise, in MKS rayls; piiIs incident sound pressure in Pa; rho0Is the air density in kg/m3；c0Is the speed of sound in air, in m; ω -2 π f is the angular frequency in rad/s, and v is the kinematic viscosity coefficient; unit is m2/s，CDIs a flow coefficient, and the specific expression is as follows:
Figure BDA0001296602430000084
wherein the content of the first and second substances,
Figure BDA0001296602430000085
Figure BDA0001296602430000086
Figure BDA0001296602430000087
Figure BDA0001296602430000088
Figure BDA0001296602430000089
Figure BDA00012966024300000810
Figure BDA0001296602430000091
Figure BDA0001296602430000092
Figure BDA0001296602430000093
Figure BDA0001296602430000094
Figure BDA0001296602430000095
Figure BDA0001296602430000096
af＝0.785-0.76(1-e-3.63t/d),bf＝3.63(t/d)0.6(18)
Figure BDA0001296602430000097
Figure BDA0001296602430000098
in the above formulae (5) to (20), PpKHas the unit of Pa, deThe unit of (a) is m, and other parameters are dimensionless parameters.
KssIs a static viscous loss parameter, which is a dimensionless parameter:
Kss＝13+10.23(t/d)-1.44(21)
Kacis an acoustic viscous loss parameter, which is a dimensionless parameter:
Kac＝3+2.32(t/d)-1(22)
h is the inertial length parameter:
Figure BDA0001296602430000099
Figure BDA00012966024300000910
κH＝13.06[1-exp(-64.9(t/d)4.365)](25)
Figure BDA00012966024300000911
Figure BDA00012966024300000912
aH＝0.725(t/d)-1.227,bH＝1.02(t/d)-1.411,mH＝3.42exp(-0.117(t/d)) (28)
in the above formulae (23) to (28), H and HresThe unit of (1) is m, and the other newly related parameters are dimensionless parameters;
at the time of resonance:
Lc＝(c0/2πf0)arccot(2πf0H/σc0) (29)；
wherein L iscIs the cavity depth in m;
step five: observing the acoustic impedance Z of the micro-perforated plate structure in the fourth step along with the incident sound pressure level PiThe curve of variation, the transition sound pressure level at which the non-linear acoustic impedance comes into play, i.e. the critical sound pressure level P, is obtainedtIn dB, if P0≤PtShowing that the selected design parameters satisfy the suppression of the nonlinear effects of the microperforated plate structure if P0>PtAnd (4) explaining that the selected design parameters are not satisfied, reducing the aperture d or increasing t/d, and then returning to the step three until structural parameters capable of realizing the nonlinear effect are obtained.
Example 1: the microperforated panel absorber design parameters that achieve nonlinear suppression to 110 dB.
Firstly, in step one, the spectrum and sound pressure level analysis is carried out on the high sound intensity noise field, and the maximum sound pressure level of the actual noise environment is determined to be P0110dB and f as the maximum noise reduction frequency point0＝2000Hz；
Subsequently, since 110dB is moderate, a larger pore size and a smaller perforation rate may be selected first, in view of manufacturing costs. Therefore, d is selected to be 0.5 × 10-3m, t/d is 1, and the perforation rate sigma is 0.0084 calculated according to the formula (1);
then, the known parameters are substituted into the formulas (2) to (28) to obtain the cavity depth Lc0.0032m and acoustic impedance versus incident sound pressure level, as shown in fig. 3. Looking at FIG. 3, it can be seen that the transition sound pressure level at which the nonlinear acoustic impedance begins to operate, i.e., the critical sound pressure level Pt＝115dB。
Subsequently, the maximum sound pressure level P of the noise reduction required for the actual noisy environment is compared0P relative to critical sound pressure leveltSize of (D), P0<PtTherefore, the structural parameters of the micro-perforated plate are designed to meet the requirements.
Example 2: the structural parameters of the sound absorber of the micro-perforated plate for realizing the nonlinear suppression to 140dB are designed.
Firstly, in step one, the spectrum and sound pressure level analysis is carried out on the high sound intensity noise field, and the maximum sound pressure level of the actual noise environment is determined to be P0140dB and f as the maximum noise reduction frequency point0＝3000Hz；
Subsequently, since 140dB is larger, it is possible to start with smaller aperture and smaller perforation rate. Therefore, d is selected to be 0.1 × 10-3m, t/d is 4, and the perforation rate σ is 0.066 calculated according to the formula (1);
then, the known parameters are substituted into the formulas (2) to (28) to obtain the cavity depth Lc0.0218m and the acoustic impedance as a function of incident sound pressure level, as shown in fig. 4. Looking at FIG. 4, it can be seen that the transition sound pressure level at which the nonlinear acoustic impedance begins to operate, i.e., the critical sound pressure level Pt＝125dB。
Subsequently, the maximum sound pressure level P of the noise reduction required for the actual noisy environment is compared0P relative to critical sound pressure leveltSize of (D), P0>PtTherefore, the structural parameters of the designed micro-perforated plate do not meet the requirements, and the step three is repeated;
since the portion of the nonlinear portion in the total acoustic impedance is inversely proportional to 1/d and t/d, the aperture d may be reduced or the plate thickness t may be increased. If the hole diameter d is kept unchanged, t/d is increased to 6, and then the perforation rate sigma is calculated to 0.0967 according to the formula (1);
then, the known parameters are substituted into the formulas (2) to (28) to obtain the cavity depth Lc0.022m and acoustic impedance as a function of incident sound pressure level, as shown in fig. 5. Looking at FIG. 5, it can be seen that the transition sound pressure level at which the nonlinear acoustic impedance begins to operate, i.e., the critical sound pressure level Pt＝135dB；
Subsequently, the maximum sound pressure level P of the noise reduction required for the actual noisy environment is compared0P relative to critical sound pressure leveltSize of (D), P0>PtTherefore, the structural parameters of the designed micro-perforated plate do not meet the requirements, and the step three is continuously repeated;
suppose that the aperture d continues to be reduced to 0.8 x 10-2m, where t/d is 7.5, the perforation rate σ is 0.1464 calculated according to equation (1).
Then, the known parameters are substituted into the formulas (2) to (28) to obtain the cavity depth Lc0.024m and a plot of acoustic impedance versus incident sound pressure level, as shown in fig. 6. Looking at FIG. 6, it can be seen that the transition sound pressure level at which the nonlinear acoustic impedance begins to operate, i.e., the critical sound pressure level Pt＝140dB；
Subsequently, the maximum sound pressure level P of the noise reduction required for the actual noisy environment is compared0P relative to critical sound pressure leveltSize of (D), P0≤PtTherefore, the structural parameters of the micro-perforated plate are designed to meet the requirements.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (1)

1. A method for suppressing the nonlinear effect of a microperforated panel through structural parameter design, comprising the steps of:
the method comprises the following steps: carrying out spectrum and sound pressure level analysis on a high sound intensity noise field, determining a linear sound pressure level range and a maximum noise reduction frequency point of expected work of a micro-perforated plate according to the frequency domain distribution condition of noise energy, and further determining limiting condition parameters and parameters to be designed, wherein the known parameters comprise:
P0: the maximum sound pressure level of the operating environment of the micro-perforated plate is dB;
f0: micro-perforated plateThe maximum noise reduction frequency point of (2), namely the resonance frequency, the noise at the frequency is maximum, and the unit is Hz;
parameters to be designed:
d, the perforation diameter of the micro-perforated plate is m;
t/d is a dimensionless parameter which represents the length-diameter ratio of the microperforated plate, and t is the plate thickness and the unit is m;
σ: the perforation rate of the micro-perforated plate is a dimensionless parameter;
step two: selecting a set of { d, t/d } parameters, d being less than 0.2 x 10-3m, t/d is more than 1;
step three: and (3) calculating the corresponding puncturing rate sigma by substituting the equation (1) according to the { d, t/d } parameter selected in the step two:
Figure FDA0002354585240000011
wherein the content of the first and second substances,
Figure FDA0002354585240000012
dimensionless variables, from which the parameter combinations { d, t/d, σ } are derived
Step four: according to the parameter combination { d, t/d, sigma } in step three and the known parameter f0And drawing the acoustic impedance Z (unit: MKS rayls) of the micro-perforated plate structure along with the incident sound pressure level P by numerical simulationiCurve of (unit: dB) variation, PiIs incident sound pressure Pii(unit: Pa) is converted into a representation in dB, and the acoustic impedance Z and the incident sound pressure P of the micro-perforated plate structureiiThe basic relationship of (A) is:
Figure FDA0002354585240000021
wherein the content of the first and second substances,
Figure FDA0002354585240000022
X/ρ0c0＝ωH/σc0-cot(ωLc/c0) (4)
in the above formulas (2) to (4), RLIs the linear acoustic resistance (MKS rayls), X is the acoustic reactance (MKS rayls), PiiIs the incident sound pressure (Pa), ρ0Is the air density (kg/m)3)，c0Is the speed of sound in air (m/s), ω ═ 2 π f is the angular frequency (rad/s), v is the coefficient of kinetic viscosity (m)2/s)，CDIs a flow coefficient, and the specific expression is as follows:
Figure FDA0002354585240000023
wherein the content of the first and second substances,
Figure FDA0002354585240000024
Figure FDA0002354585240000025
Figure FDA0002354585240000026
Figure FDA0002354585240000027
Figure FDA0002354585240000028
Figure FDA0002354585240000029
Figure FDA00023545852400000210
Figure FDA00023545852400000211
Figure FDA00023545852400000212
Figure FDA00023545852400000213
Figure FDA00023545852400000214
Figure FDA00023545852400000215
af＝0.785-0.76(1-e-3.63t/d),bf＝3.63(t/d)0.6(18)
Figure FDA0002354585240000031
Figure FDA0002354585240000032
in the above formulas (5) to (20), except for PpKHas the unit of Pa, deThe unit of (a) is m, and other parameters are dimensionless parameters;
Kssis a static viscous loss parameter, which is a dimensionless parameter:
Kss＝13+10.23(t/d)-1.44(21)
Kacis an acoustic viscous loss parameter, which is a dimensionless parameter:
Kac＝3+2.32(t/d)-1(22)
h is the inertial length parameter:
Figure FDA0002354585240000033
Figure FDA0002354585240000036
κH＝13.06[1-exp(-64.9(t/d)4.365)](25)
Figure FDA0002354585240000034
Figure FDA0002354585240000035
aH＝0.725(t/d)-1.227,bH＝1.02(t/d)-1.411,mH＝3.42exp(-0.117(t/d)) (28)
in the above formulae (23) to (28), except for H and HresThe unit of (1) is m, and the other newly related parameters are dimensionless parameters;
Lcis the cavity depth, in m, at resonance:
Lc＝(c0/2πf0)arccot(2πf0H/σc0) (29)；
step five: observing the acoustic impedance Z of the micro-perforated plate structure in the fourth step along with the incident sound pressure level PiThe curve of variation, the transition sound pressure level at which the non-linear acoustic impedance comes into play, i.e. the critical sound pressure level P, is obtainedt(unit: dB), if P0≤PtShowing that the selected design parameters satisfy the suppression of the nonlinear effects of the microperforated plate structure if P0>PtAnd (4) explaining that the selected design parameters are not satisfied, reducing the aperture d or increasing t/d, and then returning to the step three until structural parameters capable of realizing the nonlinear effect are obtained.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003041528A (en) * 2001-07-31 2003-02-13 Mitsubishi Heavy Ind Ltd Sound absorbing structure
CN1917037A (en) * 2006-09-12 2007-02-21 浙江大学 Method for improving perforation plate, and weatherability of sound absorbing structure
CN1917036A (en) * 2006-09-12 2007-02-21 浙江大学 Perforation plate for improving sound absorptivity
CN102063896A (en) * 2010-10-15 2011-05-18 南京航空航天大学 Parameter design method of resonance sound absorption structure of engineering-oriented microperforated panel
CN104715749A (en) * 2015-03-17 2015-06-17 中国科学院合肥物质科学研究院 Acoustic impedance adjusting device and method based on self-adaptive micro-perforated panel sound absorber
CN105427853A (en) * 2015-10-30 2016-03-23 东南大学 Broadband micro-perforated board sound absorber, absorber performance prediction method and absorber structure design method
CN106297762A (en) * 2016-08-16 2017-01-04 南京工业大学 A kind of method that nonlinear characteristic utilizing Helmholtz resonator changes acoustics metamaterial passband

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003041528A (en) * 2001-07-31 2003-02-13 Mitsubishi Heavy Ind Ltd Sound absorbing structure
CN1917037A (en) * 2006-09-12 2007-02-21 浙江大学 Method for improving perforation plate, and weatherability of sound absorbing structure
CN1917036A (en) * 2006-09-12 2007-02-21 浙江大学 Perforation plate for improving sound absorptivity
CN102063896A (en) * 2010-10-15 2011-05-18 南京航空航天大学 Parameter design method of resonance sound absorption structure of engineering-oriented microperforated panel
CN104715749A (en) * 2015-03-17 2015-06-17 中国科学院合肥物质科学研究院 Acoustic impedance adjusting device and method based on self-adaptive micro-perforated panel sound absorber
CN105427853A (en) * 2015-10-30 2016-03-23 东南大学 Broadband micro-perforated board sound absorber, absorber performance prediction method and absorber structure design method
CN106297762A (en) * 2016-08-16 2017-01-04 南京工业大学 A kind of method that nonlinear characteristic utilizing Helmholtz resonator changes acoustics metamaterial passband

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