Log-layer mismatch and modeling of the fluctuating wall stress in wall-modeled large-eddy simulations

Xiang Yang, George Ilhwan Park, Parviz Moin

    Research output: Contribution to journalArticle

    18 Citations (Scopus)

    Abstract

    Log-layer mismatch refers to a chronic problem found in wall-modeled large-eddy simulation (WMLES) or detached-eddy simulation, where the modeled wall-shear stress deviates from the true one by approximately 15%. Many efforts have been made to resolve this mismatch. The often-used fixes, which are generally ad hoc, include modifying subgrid-scale stress models, adding a stochastic forcing, and moving the LES-wall-model matching location away from the wall. An analysis motivated by the integral wall-model formalism suggests that log-layer mismatch is resolved by the built-in physics-based temporal filtering. In this work we investigate in detail the effects of local filtering on log-layer mismatch. We show that both local temporal filtering and local wall-parallel filtering resolve log-layer mismatch without moving the LES-wall-model matching location away from the wall. Additionally, we look into the momentum balance in the near-wall region to provide an alternative explanation of how LLM occurs, which does not necessarily rely on the numerical-error argument. While filtering resolves log-layer mismatch, the quality of the wall-shear stress fluctuations predicted by WMLES does not improve with our remedy. The wall-shear stress fluctuations are highly underpredicted due to the implied use of LES filtering. However, good agreement can be found when the WMLES data are compared to the direct numerical simulation data filtered at the corresponding WMLES resolutions.

    Original languageEnglish (US)
    Article number104601
    JournalPhysical Review Fluids
    Volume2
    Issue number10
    DOIs
    StatePublished - Oct 1 2017

    Fingerprint

    Large Eddy Simulation
    Large eddy simulation
    Filtering
    Shear stress
    Wall Shear Stress
    Modeling
    Resolve
    Model Matching
    Direct numerical simulation
    Fluctuations
    Momentum
    Physics
    Forcing
    Alternatives
    Model
    Simulation

    All Science Journal Classification (ASJC) codes

    • Computational Mechanics
    • Modeling and Simulation
    • Fluid Flow and Transfer Processes

    Cite this

    @article{215a8f2ed040486abaa7affb91c617dc,
    title = "Log-layer mismatch and modeling of the fluctuating wall stress in wall-modeled large-eddy simulations",
    abstract = "Log-layer mismatch refers to a chronic problem found in wall-modeled large-eddy simulation (WMLES) or detached-eddy simulation, where the modeled wall-shear stress deviates from the true one by approximately 15{\%}. Many efforts have been made to resolve this mismatch. The often-used fixes, which are generally ad hoc, include modifying subgrid-scale stress models, adding a stochastic forcing, and moving the LES-wall-model matching location away from the wall. An analysis motivated by the integral wall-model formalism suggests that log-layer mismatch is resolved by the built-in physics-based temporal filtering. In this work we investigate in detail the effects of local filtering on log-layer mismatch. We show that both local temporal filtering and local wall-parallel filtering resolve log-layer mismatch without moving the LES-wall-model matching location away from the wall. Additionally, we look into the momentum balance in the near-wall region to provide an alternative explanation of how LLM occurs, which does not necessarily rely on the numerical-error argument. While filtering resolves log-layer mismatch, the quality of the wall-shear stress fluctuations predicted by WMLES does not improve with our remedy. The wall-shear stress fluctuations are highly underpredicted due to the implied use of LES filtering. However, good agreement can be found when the WMLES data are compared to the direct numerical simulation data filtered at the corresponding WMLES resolutions.",
    author = "Xiang Yang and Park, {George Ilhwan} and Parviz Moin",
    year = "2017",
    month = "10",
    day = "1",
    doi = "10.1103/PhysRevFluids.2.104601",
    language = "English (US)",
    volume = "2",
    journal = "Physical Review Fluids",
    issn = "2469-990X",
    publisher = "American Physical Society",
    number = "10",

    }

    Log-layer mismatch and modeling of the fluctuating wall stress in wall-modeled large-eddy simulations. / Yang, Xiang; Park, George Ilhwan; Moin, Parviz.

    In: Physical Review Fluids, Vol. 2, No. 10, 104601, 01.10.2017.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Log-layer mismatch and modeling of the fluctuating wall stress in wall-modeled large-eddy simulations

    AU - Yang, Xiang

    AU - Park, George Ilhwan

    AU - Moin, Parviz

    PY - 2017/10/1

    Y1 - 2017/10/1

    N2 - Log-layer mismatch refers to a chronic problem found in wall-modeled large-eddy simulation (WMLES) or detached-eddy simulation, where the modeled wall-shear stress deviates from the true one by approximately 15%. Many efforts have been made to resolve this mismatch. The often-used fixes, which are generally ad hoc, include modifying subgrid-scale stress models, adding a stochastic forcing, and moving the LES-wall-model matching location away from the wall. An analysis motivated by the integral wall-model formalism suggests that log-layer mismatch is resolved by the built-in physics-based temporal filtering. In this work we investigate in detail the effects of local filtering on log-layer mismatch. We show that both local temporal filtering and local wall-parallel filtering resolve log-layer mismatch without moving the LES-wall-model matching location away from the wall. Additionally, we look into the momentum balance in the near-wall region to provide an alternative explanation of how LLM occurs, which does not necessarily rely on the numerical-error argument. While filtering resolves log-layer mismatch, the quality of the wall-shear stress fluctuations predicted by WMLES does not improve with our remedy. The wall-shear stress fluctuations are highly underpredicted due to the implied use of LES filtering. However, good agreement can be found when the WMLES data are compared to the direct numerical simulation data filtered at the corresponding WMLES resolutions.

    AB - Log-layer mismatch refers to a chronic problem found in wall-modeled large-eddy simulation (WMLES) or detached-eddy simulation, where the modeled wall-shear stress deviates from the true one by approximately 15%. Many efforts have been made to resolve this mismatch. The often-used fixes, which are generally ad hoc, include modifying subgrid-scale stress models, adding a stochastic forcing, and moving the LES-wall-model matching location away from the wall. An analysis motivated by the integral wall-model formalism suggests that log-layer mismatch is resolved by the built-in physics-based temporal filtering. In this work we investigate in detail the effects of local filtering on log-layer mismatch. We show that both local temporal filtering and local wall-parallel filtering resolve log-layer mismatch without moving the LES-wall-model matching location away from the wall. Additionally, we look into the momentum balance in the near-wall region to provide an alternative explanation of how LLM occurs, which does not necessarily rely on the numerical-error argument. While filtering resolves log-layer mismatch, the quality of the wall-shear stress fluctuations predicted by WMLES does not improve with our remedy. The wall-shear stress fluctuations are highly underpredicted due to the implied use of LES filtering. However, good agreement can be found when the WMLES data are compared to the direct numerical simulation data filtered at the corresponding WMLES resolutions.

    UR - http://www.scopus.com/inward/record.url?scp=85036592171&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=85036592171&partnerID=8YFLogxK

    U2 - 10.1103/PhysRevFluids.2.104601

    DO - 10.1103/PhysRevFluids.2.104601

    M3 - Article

    AN - SCOPUS:85036592171

    VL - 2

    JO - Physical Review Fluids

    JF - Physical Review Fluids

    SN - 2469-990X

    IS - 10

    M1 - 104601

    ER -