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Shah, S., Bodén, H. & Boij, S. (2025). An experimental study on three-port measurements for acoustic characterisation of the perforate reactance. Journal of Sound and Vibration, 596, Article ID 118776.
Open this publication in new window or tab >>An experimental study on three-port measurements for acoustic characterisation of the perforate reactance
2025 (English)In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 596, article id 118776Article in journal (Refereed) Published
Abstract [en]

The usage of perforated plates in passive noise-control systems in e.g. aircraft liners and mufflers involves the standard operating conditions of grazing flow and high-amplitude acoustic incidence. This study focuses on the usage of the three-port experiment technique for the experimental passive acoustic characterisation of a perforated plate. Expanding on the previous paper about the resistance of the perforate, the influence of operating conditions on the imaginary part of the transfer impedance, i.e., the reactance is discussed here. The relationship between the end correction in the linear range, without the presence of grazing flow, and the frequency of acoustic excitation is demonstrated. The reduction in the value of the mass end correction under the individual effects of grazing flow, and high-amplitude excitation is presented. Additionally, depending on the excitation wavelength, the partial recovery of the reduced value of the end correction under simultaneous exposure is also shown. Using the experimental results, models for the end correction, and by extension the reactance are proposed. These models take into account the geometrical parameters of the perforate, and the dimensionless Mach, Shear and Strouhal numbers.

Place, publisher, year, edition, pages
Academic Press, 2025
Keywords
Grazing flow, Non-linear effects, Perforate, Reactance, Three-port technique
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-356302 (URN)10.1016/j.jsv.2024.118776 (DOI)001350200700001 ()2-s2.0-85207885360 (Scopus ID)
Note

QC 20241119

Available from: 2024-11-13 Created: 2024-11-13 Last updated: 2025-02-09Bibliographically approved
Bodén, H., Shah, S. & Boij, S. (2024). Comparison of experimental data and empirical models for nonlinear acoustic properties of perforates. In: 30th AIAA/CEAS Aeroacoustics Conference, 2024: . Paper presented at 30th AIAA/CEAS Aeroacoustics Conference, 2024, Rome, Italy, Jun 4 2023 - Jun 7 2023. American Institute of Aeronautics and Astronautics Inc, AIAA
Open this publication in new window or tab >>Comparison of experimental data and empirical models for nonlinear acoustic properties of perforates
2024 (English)In: 30th AIAA/CEAS Aeroacoustics Conference, 2024, American Institute of Aeronautics and Astronautics Inc, AIAA , 2024Conference paper, Published paper (Refereed)
Abstract [en]

Perforates are frequently used as part of sound reducing treatment in for instance aircraft engine and IC engine applications. In these applications they are exposed to fluid flow and high-level acoustic excitation, and this influences the acoustic properties of the perforate, as is well known from many published papers. The acoustic properties are usually described using a transfer impedance. The transfer impedance of a perforate sample has been studied using both a conventional impedance tube (two-port) setup and an innovative three-port setup. The three-port configuration made it possible to study both the effect of grazing flow and high-level excitation effects separately as well as jointly. The present paper concentrates on the nonlinear effects. Comparisons are made with results from previously published papers and empirical models.

Place, publisher, year, edition, pages
American Institute of Aeronautics and Astronautics Inc, AIAA, 2024
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-353558 (URN)10.2514/6.2024-3137 (DOI)2-s2.0-85202447811 (Scopus ID)
Conference
30th AIAA/CEAS Aeroacoustics Conference, 2024, Rome, Italy, Jun 4 2023 - Jun 7 2023
Note

QC 20240927

Part of ISBN 978-1-62410-720-7

Available from: 2024-09-19 Created: 2024-09-19 Last updated: 2025-02-09Bibliographically approved
Bodén, H. & Du, L. (2024). The effect of changes in downstream acoustic termination on the nonlinear acoustic properties of perforates. In: 30th AIAA/CEAS Aeroacoustics Conference, 2024: . Paper presented at 30th AIAA/CEAS Aeroacoustics Conference, 2024, Rome, Italy, Jun 4 2023 - Jun 7 2023. American Institute of Aeronautics and Astronautics Inc, AIAA
Open this publication in new window or tab >>The effect of changes in downstream acoustic termination on the nonlinear acoustic properties of perforates
2024 (English)In: 30th AIAA/CEAS Aeroacoustics Conference, 2024, American Institute of Aeronautics and Astronautics Inc, AIAA , 2024Conference paper, Published paper (Refereed)
Abstract [en]

In sound reducing treatment for aircraft engine and IC engine applications it is common to use perforates. They can then be exposed to fluid flow and high level acoustic excitation which will change their acoustic properties. To study the nonlinear high level excitation effects separately it is possible to use plane wave impedance tubes where the perforate is mounted either at an open end or in the middle of the duct with microphones on both sides. The normalized transfer impedance defined as the acoustic pressure difference over the sample divided by the particle velocity through the perforate can then be determined. The transfer impedance can for the case that the sample is mounted at the end of the tube be estimated as the difference between the impedance at the sample cross section with or without the perforate in place. When the sample is sitting in the middle of the impedance tube the acoustic pressure and particle velocity can be measured at both sides of the sample which can then be used to estimate the transfer impedance. It is then assumed that the downstream (passive termination) does not change the measured nonlinear transfer impedance meaning that the nonlinear effects are occurring only locally at the perforate because of the flow separation effects caused by the high acoustic particle velocities in the holes. Some preliminary experimental results indicates that this may not be the case. The aim of the present study is therefore to clarify this using an experimental campaign backed up by numerical simulations.

Place, publisher, year, edition, pages
American Institute of Aeronautics and Astronautics Inc, AIAA, 2024
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-353541 (URN)10.2514/6.2024-3296 (DOI)2-s2.0-85202439731 (Scopus ID)
Conference
30th AIAA/CEAS Aeroacoustics Conference, 2024, Rome, Italy, Jun 4 2023 - Jun 7 2023
Note

QC 20240927

Part of ISBN 978-1-62410-720-7

Available from: 2024-09-19 Created: 2024-09-19 Last updated: 2025-02-09Bibliographically approved
Shah, S., Bodén, H. & Boij, S. (2023). An experimental study on three-port measurements for acoustic characterisation of the perforate resistance. Journal of Sound and Vibration, 556, Article ID 117686.
Open this publication in new window or tab >>An experimental study on three-port measurements for acoustic characterisation of the perforate resistance
2023 (English)In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 556, article id 117686Article in journal (Refereed) Published
Abstract [en]

Perforated plates are frequently applied in passive noise-control systems in e.g. aircraft liners and mufflers. Many of the applications of a perforated plate involve an exposure to grazing flow and high-amplitude acoustic incidence. The ongoing scientific effort of providing experimental results using multiform test setups is continued in this study. Incorporating the three-port technique, the passive acoustic response of a perforated plate is studied under acoustic excitation from three directions in presence of grazing flow and high-amplitude acoustic excitation. The applied three-port technique has an advantage of being a direct method for impedance determination and is not bound by any boundary conditions traditionally considered in presence of grazing flow. In this study, a semi-empirical model for the normalised resistance of a perforate is presented. The model takes the Mach, Strouhal, and Shear numbers into account. Additionally, for low grazing flow speeds, the non-linear effects of resistance are found to be dependent on the grazing flow speed.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Perforate, Three-port technique, Resistance, Grazing flow, Non-linear effects
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-327428 (URN)10.1016/j.jsv.2023.117686 (DOI)000984114700001 ()2-s2.0-85152616047 (Scopus ID)
Note

QC 20230530

Available from: 2023-05-30 Created: 2023-05-30 Last updated: 2025-02-09Bibliographically approved
Bodén, H., Boij, S. & Shah, S. (2023). An investigation of perforate reactance under high level and grazing flow excitation. In: Proceedings of the 29th International Congress on Sound and Vibration, ICSV 2023: . Paper presented at 29th International Congress on Sound and Vibration, ICSV 2023, Prague, Czechia, Jul 9 2023 - Jul 13 2023. Society of Acoustics
Open this publication in new window or tab >>An investigation of perforate reactance under high level and grazing flow excitation
2023 (English)In: Proceedings of the 29th International Congress on Sound and Vibration, ICSV 2023, Society of Acoustics , 2023Conference paper, Published paper (Refereed)
Abstract [en]

Perforates are frequently used as part of sound reducing treatment in for instance aircraft engine and IC engine applications. In these applications they are exposed to fluid flow and high-level acoustic excitation, and this influences the acoustic properties of the perforate, as is well known from many published papers. The acoustic properties are usually described using a transfer impedance. In a previous part of this study the effect on the real part (resistance) of the transfer impedance was studied using both a conventional impedance tube (two-port) setup and an innovative three-port setup. The three-port configuration made it possible to study both the effect of grazing flow and high-level excitation effects separately as well as jointly. The present paper is a follow-up study where the imaginary part (reactance) of the transfer impedance is the focus. Comparisons are made with results from previously published papers and empirical models.

Place, publisher, year, edition, pages
Society of Acoustics, 2023
Keywords
aeroacoustics, effects of flow, nonlinear effects, perforates
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-337850 (URN)2-s2.0-85170644510 (Scopus ID)
Conference
29th International Congress on Sound and Vibration, ICSV 2023, Prague, Czechia, Jul 9 2023 - Jul 13 2023
Note

Part of ISBN 9788011034238

QC 20231010

Available from: 2023-10-10 Created: 2023-10-10 Last updated: 2025-02-09Bibliographically approved
Shah, S., Bodén, H. & Boij, S. (2023). Flow Acoustic Interaction In A Rectangular T-Junction With Mounted Perforate Using Acoustic Three-Port Measurements. Paper presented at INTER-NOISE and NOISE-CON Congress and Conference, Glasgow, 21-24 August, 2023. NOISE-CON proceedings, 265(3), 4480-4485
Open this publication in new window or tab >>Flow Acoustic Interaction In A Rectangular T-Junction With Mounted Perforate Using Acoustic Three-Port Measurements
2023 (English)In: NOISE-CON proceedings, ISSN 2993-2548, Vol. 265, no 3, p. 4480-4485Article in journal, Meeting abstract (Refereed) Published
Abstract [en]

Varying acoustic behaviour of perforates in presence of grazing flow and under acoustic excitation from different directions has been under research since mid-1950s. Empirical and semi-empirical studies have shown differing behaviour of the perforate transfer impedance in presence of grazing flow. Studying a perforated plate in a rectangular T-Junction, this study aims to study the perforate from three acoustic incidence directions. Scattering matrix and the acoustic transfer impedance are determined experimentally under the presence of external grazing flow to characterise the perforate and the T-Junction. In accordance with previous research, an oscillating behaviour of amplification and attenuation is observed in the empty T-Junction. Results obtained of the perforate show a similar oscillating behaviour. Comparing with the rectangular T-junction, the similarity in the flow acoustic behaviour of a perforate is shown. 

Place, publisher, year, edition, pages
Institute of Noise Control Engineering (INCE), 2023
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-352885 (URN)10.3397/in_2022_0644 (DOI)
Conference
INTER-NOISE and NOISE-CON Congress and Conference, Glasgow, 21-24 August, 2023
Note

QC 20240909

Available from: 2024-09-09 Created: 2024-09-09 Last updated: 2025-02-09Bibliographically approved
Vaddamani, C., Boij, S., Bodén, H. & Karlsson, M. (2023). Influence of pitch ratio on the acoustic properties of tube banks. In: Proceedings of the 29th International Congress on Sound and Vibration, ICSV 2023: . Paper presented at 29th International Congress on Sound and Vibration, ICSV 2023, Prague, Czechia, Jul 9 2023 - Jul 13 2023. Society of Acoustics
Open this publication in new window or tab >>Influence of pitch ratio on the acoustic properties of tube banks
2023 (English)In: Proceedings of the 29th International Congress on Sound and Vibration, ICSV 2023, Society of Acoustics , 2023Conference paper, Published paper (Refereed)
Abstract [en]

In boilers and heat exchangers devices, tube banks are used to transfer heat. One of the commonly used arrangement in heat exchangers are staggered tube banks, which consists of tubes arranged in triangular array form. The tube banks are characterized by their longitudinal and transverse pitch ratios, which is the pitch-to- diameter ratio. Based on the pitch ratio the tube bank is considered either a compact or a widely spaced tube bank arrangement. The tube bank may cause acoustic instabilities in the system. In this study, an investigation was performed to analyse the aero-acoustic properties of tube bank samples. Experiments were conducted for three staggered tube bank samples with pitch ratio varying from 1.2 (compact arrangement) to 2 (widely spaced arrangement). Passive properties determine the sound propagation through the system, while the active acoustic properties describe the acoustic source in the system. The attention is in this paper on the passive acoustic properties of staggered tube banks. The experimental results consist of scattering coefficients for samples with different pitch ratios and power balance for all three samples which are compared to see the pitch ratio effect on the acoustic properties.

Place, publisher, year, edition, pages
Society of Acoustics, 2023
Keywords
Acoustic instabilities, Passive acoustic properties, Pitch ratio, Staggered tube bank
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-337851 (URN)2-s2.0-85170647403 (Scopus ID)
Conference
29th International Congress on Sound and Vibration, ICSV 2023, Prague, Czechia, Jul 9 2023 - Jul 13 2023
Note

Part of ISBN 9788011034238

QC 20231010

Available from: 2023-10-10 Created: 2023-10-10 Last updated: 2025-02-09Bibliographically approved
Wang, J., Bennett, G. J., Humbert, T., Aurégan, Y., Åbom, M. & Bodén, H. (2023). Low-frequency Broadband Noise Absorption of Multi-chamber Micro-perforated Panel Absorbers in Normal and Grazing Acoustic Incidence. In: AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2023: . Paper presented at AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2023, San Diego, United States of America, Jun 12 2023 - Jun 16 2023. American Institute of Aeronautics and Astronautics (AIAA)
Open this publication in new window or tab >>Low-frequency Broadband Noise Absorption of Multi-chamber Micro-perforated Panel Absorbers in Normal and Grazing Acoustic Incidence
Show others...
2023 (English)In: AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2023, American Institute of Aeronautics and Astronautics (AIAA) , 2023Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a significant advancement in micro-perforated panel absorber technologies. Two distinct types of sub-wavelength multi-chamber micro-perforated panel absorbers (MC-MPPA) for low-frequency broadband noise absorption under both normal and grazing acoustic incidence conditions are developed. Micro-perforated panel absorbers (MPPAs) exhibit versatility, eco-friendliness, and a straightforward, robust construction, making them ideal acoustic solutions. A graph-theory-based two-point impedance method (TpIM) and the Cremer impedance method are used for system modeling, enabling the design of the MC-MPPA to be optimized for maximum sound absorption in a chosen frequency range for both normal and grazing acoustic incidence. This graph theory approach represents a breakthrough, as an equivalent circuit model approach could not be applied to such complex models. Under normal incidence conditions, the experimental overall absorption coefficient is measured to be 0.8273 for a 22 mmthick MC-MPPA in the frequency range of [660 2000] Hz, and 0.8284 for a 52 mm thick MC-MPPA in the frequency range of [400 2000] Hz. Under grazing incidence conditions, an optimized MC-MPPA with a mere 30 mm sub-chamber depth achieves a transmission loss of 66 dB at 1180 Hz. Additionally, a 50 mm sub-chamber depth yields a transmission loss greater than 10 dB over an 880 Hz wide frequency range: [820 1700] Hz. The developed MC-MPPA technologies hold great promise for various duct noise attenuation applications including aeroengine acoustic liners.

Place, publisher, year, edition, pages
American Institute of Aeronautics and Astronautics (AIAA), 2023
National Category
Fluid Mechanics Vehicle and Aerospace Engineering
Identifiers
urn:nbn:se:kth:diva-351751 (URN)10.2514/6.2023-3829 (DOI)2-s2.0-85199865805 (Scopus ID)
Conference
AIAA Aviation and Aeronautics Forum and Exposition, AIAA AVIATION Forum 2023, San Diego, United States of America, Jun 12 2023 - Jun 16 2023
Note

 Part of ISBN [9781624107047]

QC 20240820

Available from: 2024-08-13 Created: 2024-08-13 Last updated: 2025-02-14Bibliographically approved
Shah, S., Bodén, H. & Boij, S. (2023). On the sensitivity analysis of three-port measurements for acoustic characterisation of perforates. In: Proceedings of the 29th International Congress on Sound and Vibration, ICSV 2023: . Paper presented at 29th International Congress on Sound and Vibration, ICSV 2023, Prague, Czechia, Jul 9 2023 - Jul 13 2023. Society of Acoustics
Open this publication in new window or tab >>On the sensitivity analysis of three-port measurements for acoustic characterisation of perforates
2023 (English)In: Proceedings of the 29th International Congress on Sound and Vibration, ICSV 2023, Society of Acoustics , 2023Conference paper, Published paper (Refereed)
Abstract [en]

Perforates, often with a backing cavity, are used in noise reducing liners and silencers for aircraft engines and internal combustion engines. Direct methods of impedance estimation can be used for the acoustic characterisation of the perforated plates standalone, without the backing cavity, in presence of grazing flow. The three-port technique is a direct method for estimating the transfer impedance of perforates in presence of grazing flow and high-amplitude acoustic excitation. In a previous study, the dependence of the experimentally determined transfer impedance on the operating conditions, namely the in-duct temperature, the grazing flow speed and microphone distances is shown. This paper is a follow up to the previous study and attempts to quantify the effect of variations in these testing conditions on the real part of the transfer impedance, i.e., the resistance. The possible sources of errors and deviations in the determination of the operating conditions are discussed. Based on the uncertainty range of the operating conditions, a Monte-Carlo simulation is performed to calculate the confidence intervals of the results. Additionally, the effect of the error distribution on the confidence intervals is displayed.

Place, publisher, year, edition, pages
Society of Acoustics, 2023
Keywords
error analysis, grazing flow, impedance, Monte-Carlo analysis, perforates
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-337849 (URN)2-s2.0-85170648533 (Scopus ID)
Conference
29th International Congress on Sound and Vibration, ICSV 2023, Prague, Czechia, Jul 9 2023 - Jul 13 2023
Note

Part of ISBN 9788011034238

QC 20231010

Available from: 2023-10-10 Created: 2023-10-10 Last updated: 2025-02-09Bibliographically approved
Vaddamani, C., Boij, S., Bodén, H. & Karlsson, M. (2022). Effect of Pitch Ratio of Tube Banks on Passive Acoustic Properties. In: Internoise 2022: 51st International Congress and Exposition on Noise Control Engineering. Paper presented at 51st International Congress and Exposition on Noise Control Engineering, Internoise 2022, Glasgow, United Kingdom of Great Britain and Northern Ireland, Aug 21 2022 - Aug 24 2022. The Institute of Noise Control Engineering of the USA, Inc.
Open this publication in new window or tab >>Effect of Pitch Ratio of Tube Banks on Passive Acoustic Properties
2022 (English)In: Internoise 2022: 51st International Congress and Exposition on Noise Control Engineering, The Institute of Noise Control Engineering of the USA, Inc. , 2022Conference paper, Published paper (Refereed)
Abstract [en]

Tube banks are common design elements in heat exchangers. The most common tube bank patterns are in-line tube banks which consists of tubes spaced parallel and equally. Tube banks are characterized by their longitudinal and transverse pitch ratios (pitch to diameter). The tube bank with a pitch ratio of less than 1.25 is considered a compact tube bank and a pitch ratio equal to or greater than 2 is considered as widely spaced. In this paper, the attention is focused on the effects of pitch ratio in tube banks on its passive acoustics properties which are experimentally investigated. The flow duct experimentation is performed with flow to analyse the passive acoustic properties of tube banks. The experiment is conducted for three In-line tube banks with pitch ratios 1.2,1.4 and 2. The Experimental results consist of scattering matrix coefficients and power balance. The results are compared to see the pitch ratio effect. Transmission and reflection coefficients were found to increase with frequency for higher flow speeds and shows more waviness for compact tube bank. The power balance is calculated to see the amplification and attenuation effects of the tube bank. It is observed that compact tube banks give amplification for higher frequencies and wide spaced tube bank give moderate attenuation for all frequencies.

Place, publisher, year, edition, pages
The Institute of Noise Control Engineering of the USA, Inc., 2022
Keywords
In-line arrangement, Passive Acoustic properties, Pitch Ratio, Tube Banks
National Category
Fluid Mechanics
Identifiers
urn:nbn:se:kth:diva-333414 (URN)2-s2.0-85147457158 (Scopus ID)
Conference
51st International Congress and Exposition on Noise Control Engineering, Internoise 2022, Glasgow, United Kingdom of Great Britain and Northern Ireland, Aug 21 2022 - Aug 24 2022
Note

Part of ISBN 9781906913427

QC 20230801

Available from: 2023-08-01 Created: 2023-08-01 Last updated: 2025-02-09Bibliographically approved
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