Validation of a Method for Determining the Modal Composition of a Tonal Sound Field in a Cylindrical Duct Based on Synchronous Measurements in the Duct and the Far Field in Absence of Flow

N. N. Ostrikov; Остриков Н. Н.; M. A. Yakovets; Яковец М. А.; I. S. Ipatov; Ипатов И. С.; I. V.  Pankratov; Панкратов И. В.

doi:10.31857/S0320791923600099

Validation of a Method for Determining the Modal Composition of a Tonal Sound Field in a Cylindrical Duct Based on Synchronous Measurements in the Duct and the Far Field in Absence of Flow

Authors: Ostrikov N.N.¹, Yakovets M.A.¹, Ipatov I.S.¹, Pankratov I.V.¹
Affiliations:
1. Acoustic Department, Central Aerohydrodynamic Institute, 105005, Moscow, Russia
Issue: Vol 69, No 2 (2023)
Pages: 216-229
Section: АТМОСФЕРНАЯ И АЭРОАКУСТИКА
URL: https://journals.rcsi.science/0320-7919/article/view/134429
DOI: https://doi.org/10.31857/S0320791923600099
EDN: https://elibrary.ru/IULPLA
ID: 134429

Cite item

Full Text

Open Access
Restricted Access

Access granted
Restricted Access

Subscription Access

Abstract
About the authors
References
Supplementary files
Statistics

Abstract

A method has been developed for determining the modal composition of correlated sound modes propagating in a cylindrical duct, the peculiarity of which is that the effect of sound reflection from the open end of the duct is taken into account by numerical or analytical calculation of the reflection coefficients. This method was validated in the TsAGI AC-2 anechoic chamber, in which the sound field was created in the duct of a small-scale air intake model using 12 speakers at fixed frequencies; the modal composition was determined using 48 microphones installed flush with the duct walls, and synchronous measurements of the directivity of sound emission from the open end of the duct in the far field were carried out. In this case, on based on the found amplitudes of sound modes in the duct, the radiation characteristics in the far field were calculated using an analytical solution for sound emission from a semi-infinite cylindrical duct, the results of which were compared with the measurement results. It is shown that the amplitudes of sound modes found according to the developed method make it possible to reconstruct the far sound field characteristics with high accuracy in cases where the number of generated propagating modes in the duct does not exceed the number of installed microphones in the cylindrical array.

Keywords

modal analysis of the sound field in ducts, coherent sound modes, cylindrical duct

References

Dougherty R.P., Mendoza J.M. Nacelle In-duct Beamforming using Modal Steering Vectors // AIAA Paper. 2008. 2008–2812.
Sijtsma P. CLEAN based on spatial source coherence // Int. J. Aeroacoustics. 2009. V. 6. № 4. P. 357–374.
Lowis C.R., Joseph P.F., Kempton A.J. Estimation of the far-field directivity of broadband aeroengine fan noise using an in-duct axial microphone array // J. Sound. Vib. 2010. V. 329. P. 3940–3957.
Tester B.J., Murray P.B. An in-duct to far-field phased array technique for validation of fan broadband liner per-formance at representative Mach numbers // AIAA Paper. 2013. 2013–2211.
Tester B.J., Özyörük Y. Predicting far-field broadband noise levels from in-duct phased array measurements // AIAA Paper. 2014. 2014–2913.
Tester B.J., Özyörük Y., Sutliff D.L., Bozak R.F. Predicting far-field broadband noise levels from in-duct phased array measurements // ICSV-22. Florence (Italy) 12–16 July. 2015.
Dougherty R.P. Mutual Incoherence of Broadband Duct Acoustic Modes // AIAA Paper. 2016. 2016–3032.
Tapken U., Pardowitzy B., Behnz M. Radial mode analysis of fan broadband noise // AIAA Paper. 2017. 2017–3715.
Dougherty R.P., Bozak R.F. Two-dimensional Modal Beamforming in Wavenumber Space for Duct Acoustics // AIAA Paper. 2018. 2018–2805.
Fauqueux S., Davy R. Modal Deconvolution Method in a Finite Circular Duct, using Flush-mounted Microphones // AIAA Paper. 2018. 2018–3927.
Fauqueux S., Davy R., Méry F. Duct modal detection tool to characterize the noise source generated by an air pump // AIAA Paper. 2019. 2019–2419.
Копьев В.Ф., Остриков Н.Н., Яковец М.А., Ипатов М.С., Кругляева А.Е., Сидоров С.Ю. Излучение звука из открытого конца канала, моделирующего воздухозаборник авиадвигателя в статических условиях и в потоке // Акуст. журн. 2019. Т. 65. № 1. С. 59–73.
Tam C.K.W., Parrish S.A., Envia E., Chien E.W. Physics of Acoustic Radiation from Jet Engine Inlets // AIAA Paper. 2012. 2012–2243.
Ostrikov N.N., Yakovets M.A., Ipatov M.S., Pankratov I.V., Denisov S.L. Experimental study of the effect of flow velocity at the inlet on the azimuthal mode radiation: static and flight // 24th Int. Congress on Sound and Vibration, ICSV 2017, 2017.
Вайнштейн Л.А. // Докл. АН СССР. 1947. Т. 58. № 11. С. 1957.
Levine H., Schwinger J. Radiation of sound from a circular pipe // Phys. Rev. 1948. V. 73. P. 383–406.
Вайнштейн Л.А. Теория дифракции и метод факторизации. М.: Советское радио, 1966. 432 с.
Lympany S.V., Karon A.Z., Wadsworth M.L., Funk R., Ahuja K.K. An Experimental Facility for Measuring the Acoustic Reflection and Transmission of Higher-Order Modes in Heated Flows, Part 1: Design and Methodology // AIAA Paper. 2018. 2018–3133.
Остриков Н.Н. Асимптотический метод учета влияния пограничного слоя высокоскоростного потока на характеристики распространения звуковых мод в цилиндрическом канале с жесткими стенками // Докл. Рос. Акад. наук. Физика, технические науки. 2022. Т. 506. № 1. С. 104–112.