A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump

    Research output: Chapter in Book/Conference paperConference paper

    Abstract

    In this paper, the 3-D unsteady turbulent flow inside a centrifugal pump is investigated by computational fluid dynamics (CFD) in ANSYS CFX, using Detached Eddy Simulation (DES) as the turbulence approach. The pump has a single end-suction and a single volute discharge. The impeller is semi-open (unshrouded with baseplate) and has five backswept blades and pump-out back blades. The CFD model of the pump consists of the inlet, the impeller, and the volute. A sliding mesh technique has been applied to the interfaces in order to allow unsteady interactions between the rotating impeller and the stationary parts. These unsteady interactions generate pressure fluctuations over the volute casing and blade surfaces that are hydroacoustic dipoles according to Lighthill’s acoustic analogy theory. The pressure fluctuation spectra at the volute tongue show that pressure fluctuations are generated mainly by the discrete components related to the impeller rotation at low frequencies, especially the blade-passing frequency (BPF) component. This component is approximately 1% of the reference dynamic pressure 0.5ρν22 where ν2 is the circumferential velocity at the impeller outlet. The discrete components with frequency larger than 4 times BPF are no longer obvious in the spectra. Compared to the experimental results, the CFD simulation predicts much lower amplitudes for the broad band pressure fluctuations. This is reasonable, because DES combines a classical Reynolds averaged Navier Stokes (RANS) simulation with elements of Large Eddy Simulation (LES), and both RANS and LES use average methods which filter out the high frequency fluctuations. Nevertheless, CFD is capable of accurately predict the BPF component.
    The pressure fluctuations on the casing and blade surfaces are extracted and modelled as the stationary and rotary dipoles, respectively, according to the Ffowcs Williams and Hawkings (FW-H) equation of the acoustic analogy theory. After Fast Fourier Transform, the spectra of the pressure fluctuations are obtained, and are used to predict the tonal hydrodynamic sound radiation at BPF and its low order harmonics. The sound radiation of casing surface dipoles is calculated by extracting the tonal components, and performing a surface integration with the fundamental solution to Helmholtz equation as the kernel. A frequency domain formulation of the FW-H equation with the moving surface dipole is employed to predict the tonal blade noise. The results from these acoustical simulations show that the sound power generated by the casing surface dipole is three orders of magnitude higher than that of the blade surface dipole, and the main hydroacoustic sources are located at the volute tongue.
    Copyright © 2015 by ASME
    Original languageEnglish
    Title of host publicationProceedings of ASME International Mechanical Engineering Congress & Exposition
    Place of PublicationUnited States
    PublisherASME
    Pages1-9
    VolumeVolume 13
    ISBN (Print)9780791857564
    DOIs
    Publication statusPublished - 2015
    EventASME 2015 International Mechanical Engineering Congress and Exposition, IMECE 2015 - USA, Houston, United States
    Duration: 13 Nov 201519 Nov 2015
    Conference number: 121052

    Conference

    ConferenceASME 2015 International Mechanical Engineering Congress and Exposition, IMECE 2015
    Abbreviated titleIMECE 2015
    CountryUnited States
    CityHouston
    Period13/11/1519/11/15

    Fingerprint

    centrifugal pumps
    unsteady flow
    blades
    flow distribution
    hydrodynamics
    acoustics
    casing
    dipoles
    computational fluid dynamics
    tongue
    underwater acoustics
    large eddy simulation
    pumps
    simulation
    vortices
    Helmholtz equations
    dynamic pressure
    suction
    radiation
    outlets

    Cite this

    Cai, J., Pan, J., & Guzzomi, A. (2015). A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump. In Proceedings of ASME International Mechanical Engineering Congress & Exposition (Vol. Volume 13, pp. 1-9). United States: ASME. https://doi.org/10.1115/IMECE2015-53163
    Cai, J. ; Pan, Jie ; Guzzomi, Andrew. / A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump. Proceedings of ASME International Mechanical Engineering Congress & Exposition. Vol. Volume 13 United States : ASME, 2015. pp. 1-9
    @inproceedings{06746063966b4b8faab04a0a2a949f39,
    title = "A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump",
    abstract = "In this paper, the 3-D unsteady turbulent flow inside a centrifugal pump is investigated by computational fluid dynamics (CFD) in ANSYS CFX, using Detached Eddy Simulation (DES) as the turbulence approach. The pump has a single end-suction and a single volute discharge. The impeller is semi-open (unshrouded with baseplate) and has five backswept blades and pump-out back blades. The CFD model of the pump consists of the inlet, the impeller, and the volute. A sliding mesh technique has been applied to the interfaces in order to allow unsteady interactions between the rotating impeller and the stationary parts. These unsteady interactions generate pressure fluctuations over the volute casing and blade surfaces that are hydroacoustic dipoles according to Lighthill’s acoustic analogy theory. The pressure fluctuation spectra at the volute tongue show that pressure fluctuations are generated mainly by the discrete components related to the impeller rotation at low frequencies, especially the blade-passing frequency (BPF) component. This component is approximately 1{\%} of the reference dynamic pressure 0.5ρν22 where ν2 is the circumferential velocity at the impeller outlet. The discrete components with frequency larger than 4 times BPF are no longer obvious in the spectra. Compared to the experimental results, the CFD simulation predicts much lower amplitudes for the broad band pressure fluctuations. This is reasonable, because DES combines a classical Reynolds averaged Navier Stokes (RANS) simulation with elements of Large Eddy Simulation (LES), and both RANS and LES use average methods which filter out the high frequency fluctuations. Nevertheless, CFD is capable of accurately predict the BPF component.The pressure fluctuations on the casing and blade surfaces are extracted and modelled as the stationary and rotary dipoles, respectively, according to the Ffowcs Williams and Hawkings (FW-H) equation of the acoustic analogy theory. After Fast Fourier Transform, the spectra of the pressure fluctuations are obtained, and are used to predict the tonal hydrodynamic sound radiation at BPF and its low order harmonics. The sound radiation of casing surface dipoles is calculated by extracting the tonal components, and performing a surface integration with the fundamental solution to Helmholtz equation as the kernel. A frequency domain formulation of the FW-H equation with the moving surface dipole is employed to predict the tonal blade noise. The results from these acoustical simulations show that the sound power generated by the casing surface dipole is three orders of magnitude higher than that of the blade surface dipole, and the main hydroacoustic sources are located at the volute tongue.Copyright {\circledC} 2015 by ASME",
    author = "J. Cai and Jie Pan and Andrew Guzzomi",
    year = "2015",
    doi = "10.1115/IMECE2015-53163",
    language = "English",
    isbn = "9780791857564",
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    pages = "1--9",
    booktitle = "Proceedings of ASME International Mechanical Engineering Congress & Exposition",
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    Cai, J, Pan, J & Guzzomi, A 2015, A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump. in Proceedings of ASME International Mechanical Engineering Congress & Exposition. vol. Volume 13, ASME, United States, pp. 1-9, ASME 2015 International Mechanical Engineering Congress and Exposition, IMECE 2015, Houston, United States, 13/11/15. https://doi.org/10.1115/IMECE2015-53163

    A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump. / Cai, J.; Pan, Jie; Guzzomi, Andrew.

    Proceedings of ASME International Mechanical Engineering Congress & Exposition. Vol. Volume 13 United States : ASME, 2015. p. 1-9.

    Research output: Chapter in Book/Conference paperConference paper

    TY - GEN

    T1 - A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump

    AU - Cai, J.

    AU - Pan, Jie

    AU - Guzzomi, Andrew

    PY - 2015

    Y1 - 2015

    N2 - In this paper, the 3-D unsteady turbulent flow inside a centrifugal pump is investigated by computational fluid dynamics (CFD) in ANSYS CFX, using Detached Eddy Simulation (DES) as the turbulence approach. The pump has a single end-suction and a single volute discharge. The impeller is semi-open (unshrouded with baseplate) and has five backswept blades and pump-out back blades. The CFD model of the pump consists of the inlet, the impeller, and the volute. A sliding mesh technique has been applied to the interfaces in order to allow unsteady interactions between the rotating impeller and the stationary parts. These unsteady interactions generate pressure fluctuations over the volute casing and blade surfaces that are hydroacoustic dipoles according to Lighthill’s acoustic analogy theory. The pressure fluctuation spectra at the volute tongue show that pressure fluctuations are generated mainly by the discrete components related to the impeller rotation at low frequencies, especially the blade-passing frequency (BPF) component. This component is approximately 1% of the reference dynamic pressure 0.5ρν22 where ν2 is the circumferential velocity at the impeller outlet. The discrete components with frequency larger than 4 times BPF are no longer obvious in the spectra. Compared to the experimental results, the CFD simulation predicts much lower amplitudes for the broad band pressure fluctuations. This is reasonable, because DES combines a classical Reynolds averaged Navier Stokes (RANS) simulation with elements of Large Eddy Simulation (LES), and both RANS and LES use average methods which filter out the high frequency fluctuations. Nevertheless, CFD is capable of accurately predict the BPF component.The pressure fluctuations on the casing and blade surfaces are extracted and modelled as the stationary and rotary dipoles, respectively, according to the Ffowcs Williams and Hawkings (FW-H) equation of the acoustic analogy theory. After Fast Fourier Transform, the spectra of the pressure fluctuations are obtained, and are used to predict the tonal hydrodynamic sound radiation at BPF and its low order harmonics. The sound radiation of casing surface dipoles is calculated by extracting the tonal components, and performing a surface integration with the fundamental solution to Helmholtz equation as the kernel. A frequency domain formulation of the FW-H equation with the moving surface dipole is employed to predict the tonal blade noise. The results from these acoustical simulations show that the sound power generated by the casing surface dipole is three orders of magnitude higher than that of the blade surface dipole, and the main hydroacoustic sources are located at the volute tongue.Copyright © 2015 by ASME

    AB - In this paper, the 3-D unsteady turbulent flow inside a centrifugal pump is investigated by computational fluid dynamics (CFD) in ANSYS CFX, using Detached Eddy Simulation (DES) as the turbulence approach. The pump has a single end-suction and a single volute discharge. The impeller is semi-open (unshrouded with baseplate) and has five backswept blades and pump-out back blades. The CFD model of the pump consists of the inlet, the impeller, and the volute. A sliding mesh technique has been applied to the interfaces in order to allow unsteady interactions between the rotating impeller and the stationary parts. These unsteady interactions generate pressure fluctuations over the volute casing and blade surfaces that are hydroacoustic dipoles according to Lighthill’s acoustic analogy theory. The pressure fluctuation spectra at the volute tongue show that pressure fluctuations are generated mainly by the discrete components related to the impeller rotation at low frequencies, especially the blade-passing frequency (BPF) component. This component is approximately 1% of the reference dynamic pressure 0.5ρν22 where ν2 is the circumferential velocity at the impeller outlet. The discrete components with frequency larger than 4 times BPF are no longer obvious in the spectra. Compared to the experimental results, the CFD simulation predicts much lower amplitudes for the broad band pressure fluctuations. This is reasonable, because DES combines a classical Reynolds averaged Navier Stokes (RANS) simulation with elements of Large Eddy Simulation (LES), and both RANS and LES use average methods which filter out the high frequency fluctuations. Nevertheless, CFD is capable of accurately predict the BPF component.The pressure fluctuations on the casing and blade surfaces are extracted and modelled as the stationary and rotary dipoles, respectively, according to the Ffowcs Williams and Hawkings (FW-H) equation of the acoustic analogy theory. After Fast Fourier Transform, the spectra of the pressure fluctuations are obtained, and are used to predict the tonal hydrodynamic sound radiation at BPF and its low order harmonics. The sound radiation of casing surface dipoles is calculated by extracting the tonal components, and performing a surface integration with the fundamental solution to Helmholtz equation as the kernel. A frequency domain formulation of the FW-H equation with the moving surface dipole is employed to predict the tonal blade noise. The results from these acoustical simulations show that the sound power generated by the casing surface dipole is three orders of magnitude higher than that of the blade surface dipole, and the main hydroacoustic sources are located at the volute tongue.Copyright © 2015 by ASME

    U2 - 10.1115/IMECE2015-53163

    DO - 10.1115/IMECE2015-53163

    M3 - Conference paper

    SN - 9780791857564

    VL - Volume 13

    SP - 1

    EP - 9

    BT - Proceedings of ASME International Mechanical Engineering Congress & Exposition

    PB - ASME

    CY - United States

    ER -

    Cai J, Pan J, Guzzomi A. A numerical study of the unsteady flow field and tonal hydrodynamic sound of a centrifugal pump. In Proceedings of ASME International Mechanical Engineering Congress & Exposition. Vol. Volume 13. United States: ASME. 2015. p. 1-9 https://doi.org/10.1115/IMECE2015-53163