On the enhancement of coupling potential flow models to RANS solvers for the prediction of propeller effective wakes

Antonio Sanchez Caja (Corresponding Author), Jussi Martio, Ilkka Saisto, T Siikonen

    Research output: Contribution to journalArticleScientificpeer-review

    13 Citations (Scopus)

    Abstract

    The calculation of the effective wake within the CFD context is usually made by combining a potential-flow method for modeling the propeller forces with a RANS equation solver for simulating the viscous flow around the hull and possible appendages. The different assumptions and/or simplifications made in the potential flow model relative to the viscous flow solver may result in significant errors in the prediction of the effective wake particularly for high loadings. This is especially troublesome for ships with full forms where large differences are expected between the nominal and effective wake, and for special propulsion applications such as contra-rotating units. Such errors are responsible within the hydrodynamic design problem for an unadjusted prediction of the propeller pitch, and within the hydrodynamic analysis problem for a deficient prediction of self-propulsion point. This paper presents an approach based on correction factors which converts propeller-induced velocities approximately estimated via potential flow theory into viscous induced velocities on the basis of a viscous flow RANS analysis. The correction factors are calculated for one reference advance number and work accurately in a neighboring region where the propeller loading may change about ±50 %. This procedure allows controlling one of the errors present in the calculation of effective wakes, namely the error derived from coupling a potential-flow method for the representation of the propeller with a RANS solver. Consequently, it permits calculating the effective wake more precisely. The approach is illustrated for a simple case in which the potential flow model representing the propeller is an actuator disk
    Original languageEnglish
    Pages (from-to)104-117
    Number of pages13
    JournalJournal of Marine Science and Technology
    Volume20
    Issue number1
    DOIs
    Publication statusPublished - 2014
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    potential flow
    Potential flow
    Propellers
    viscous flow
    Viscous flow
    prediction
    Propulsion
    hydrodynamics
    Hydrodynamics
    Actuator disks
    hull
    Computational fluid dynamics
    Ships
    modeling

    Keywords

    • Coupling
    • CRP
    • effective wake
    • pod propulsor
    • potential flow
    • RANS

    Cite this

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    title = "On the enhancement of coupling potential flow models to RANS solvers for the prediction of propeller effective wakes",
    abstract = "The calculation of the effective wake within the CFD context is usually made by combining a potential-flow method for modeling the propeller forces with a RANS equation solver for simulating the viscous flow around the hull and possible appendages. The different assumptions and/or simplifications made in the potential flow model relative to the viscous flow solver may result in significant errors in the prediction of the effective wake particularly for high loadings. This is especially troublesome for ships with full forms where large differences are expected between the nominal and effective wake, and for special propulsion applications such as contra-rotating units. Such errors are responsible within the hydrodynamic design problem for an unadjusted prediction of the propeller pitch, and within the hydrodynamic analysis problem for a deficient prediction of self-propulsion point. This paper presents an approach based on correction factors which converts propeller-induced velocities approximately estimated via potential flow theory into viscous induced velocities on the basis of a viscous flow RANS analysis. The correction factors are calculated for one reference advance number and work accurately in a neighboring region where the propeller loading may change about ±50 {\%}. This procedure allows controlling one of the errors present in the calculation of effective wakes, namely the error derived from coupling a potential-flow method for the representation of the propeller with a RANS solver. Consequently, it permits calculating the effective wake more precisely. The approach is illustrated for a simple case in which the potential flow model representing the propeller is an actuator disk",
    keywords = "Coupling, CRP, effective wake, pod propulsor, potential flow, RANS",
    author = "{Sanchez Caja}, Antonio and Jussi Martio and Ilkka Saisto and T Siikonen",
    note = "Project code: 70501 EU_TRIPOD",
    year = "2014",
    doi = "10.1007/s00773-014-0255-4",
    language = "English",
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    pages = "104--117",
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    On the enhancement of coupling potential flow models to RANS solvers for the prediction of propeller effective wakes. / Sanchez Caja, Antonio (Corresponding Author); Martio, Jussi; Saisto, Ilkka; Siikonen, T.

    In: Journal of Marine Science and Technology, Vol. 20, No. 1, 2014, p. 104-117.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - On the enhancement of coupling potential flow models to RANS solvers for the prediction of propeller effective wakes

    AU - Sanchez Caja, Antonio

    AU - Martio, Jussi

    AU - Saisto, Ilkka

    AU - Siikonen, T

    N1 - Project code: 70501 EU_TRIPOD

    PY - 2014

    Y1 - 2014

    N2 - The calculation of the effective wake within the CFD context is usually made by combining a potential-flow method for modeling the propeller forces with a RANS equation solver for simulating the viscous flow around the hull and possible appendages. The different assumptions and/or simplifications made in the potential flow model relative to the viscous flow solver may result in significant errors in the prediction of the effective wake particularly for high loadings. This is especially troublesome for ships with full forms where large differences are expected between the nominal and effective wake, and for special propulsion applications such as contra-rotating units. Such errors are responsible within the hydrodynamic design problem for an unadjusted prediction of the propeller pitch, and within the hydrodynamic analysis problem for a deficient prediction of self-propulsion point. This paper presents an approach based on correction factors which converts propeller-induced velocities approximately estimated via potential flow theory into viscous induced velocities on the basis of a viscous flow RANS analysis. The correction factors are calculated for one reference advance number and work accurately in a neighboring region where the propeller loading may change about ±50 %. This procedure allows controlling one of the errors present in the calculation of effective wakes, namely the error derived from coupling a potential-flow method for the representation of the propeller with a RANS solver. Consequently, it permits calculating the effective wake more precisely. The approach is illustrated for a simple case in which the potential flow model representing the propeller is an actuator disk

    AB - The calculation of the effective wake within the CFD context is usually made by combining a potential-flow method for modeling the propeller forces with a RANS equation solver for simulating the viscous flow around the hull and possible appendages. The different assumptions and/or simplifications made in the potential flow model relative to the viscous flow solver may result in significant errors in the prediction of the effective wake particularly for high loadings. This is especially troublesome for ships with full forms where large differences are expected between the nominal and effective wake, and for special propulsion applications such as contra-rotating units. Such errors are responsible within the hydrodynamic design problem for an unadjusted prediction of the propeller pitch, and within the hydrodynamic analysis problem for a deficient prediction of self-propulsion point. This paper presents an approach based on correction factors which converts propeller-induced velocities approximately estimated via potential flow theory into viscous induced velocities on the basis of a viscous flow RANS analysis. The correction factors are calculated for one reference advance number and work accurately in a neighboring region where the propeller loading may change about ±50 %. This procedure allows controlling one of the errors present in the calculation of effective wakes, namely the error derived from coupling a potential-flow method for the representation of the propeller with a RANS solver. Consequently, it permits calculating the effective wake more precisely. The approach is illustrated for a simple case in which the potential flow model representing the propeller is an actuator disk

    KW - Coupling

    KW - CRP

    KW - effective wake

    KW - pod propulsor

    KW - potential flow

    KW - RANS

    U2 - 10.1007/s00773-014-0255-4

    DO - 10.1007/s00773-014-0255-4

    M3 - Article

    VL - 20

    SP - 104

    EP - 117

    JO - Journal of Marine Science and Technology

    JF - Journal of Marine Science and Technology

    SN - 0948-4280

    IS - 1

    ER -