[
    {
        "id": "authors:z65mw-2y639",
        "collection": "authors",
        "collection_id": "z65mw-2y639",
        "cite_using_url": "https://authors.library.caltech.edu/records/z65mw-2y639",
        "type": "conference_item",
        "title": "Grid Resolution Assessment in Wall-Modeled Large-Eddy Simulation via Velocity Gradient Partitioning",
        "book_title": "AIAA SCITECH 2025 Forum",
        "author": [
            {
                "family_name": "Zhou",
                "given_name": "Di",
                "orcid": "0000-0003-3387-1446",
                "clpid": "Zhou-Di"
            },
            {
                "family_name": "Arun",
                "given_name": "Rahul",
                "orcid": "0000-0002-5942-169X",
                "clpid": "Arun-Rahul"
            },
            {
                "family_name": "Colonius",
                "given_name": "Tim",
                "orcid": "0000-0003-0326-3909",
                "clpid": "Colonius-T"
            },
            {
                "family_name": "Bae",
                "given_name": "H. Jane",
                "orcid": "0000-0001-6789-6209",
                "clpid": "Bae-Hyunji-Jane"
            }
        ],
        "abstract": "<p>Wall-modeled large-eddy simulation (WMLES) has attracted significant attention in engineering applications as a high-fidelity simulation technique not limited by near-wall resolution requirements. It significantly reduces computational costs by resolving the energy-containing and dynamically important scales of turbulence far from the wall while modeling the effects of near-wall eddies. However, the inherent grid dependence of WMLES results raises the question of how to determine an adequate yet minimal resolution for the outer region. To address this question, we propose an approach to assess grid resolution that does not rely on a priori knowledge of domain-specific flow statistics. This approach leverages the velocity gradient partitioning, which provides an expressive, broadly applicable, and Galilean invariant description of local flow features. The error metric we define represents the deviation of the partitioning far from the wall in WMLES from the partitioning associated with isotropic turbulence. Using simulations of turbulent channel flow, we compare the convergence trends of this metric with those of conventional metrics representing turbulence kinetic energy errors. The partitioning metric effectively captures the response of resolved small-scale flow features to grid resolution and various other mesh and simulation parameters. It is particularly sensitive to the mesh-cell aspect ratio and subgrid-scale modeling; however, it is less sensitive to the friction Reynolds number and wall boundary conditions, which primarily impact large-scale flow features. Hence, the metric provides valuable and inexpensive insight into the sensitivity of small-scale flow features. While it alone cannot be used to holistically validate the accuracy of simulation results, coupling it with a metric that diagnoses large-scale flow features would provide a more complete picture. Beyond turbulent channel flow, preliminary results for flow over a Gaussian bump highlight the potential for the present approach to be applied to WMLES in more complex geometries.</p>",
        "doi": "10.2514/6.2025-1376",
        "isbn": "9781624107238",
        "publisher": "AIAA",
        "place_of_publication": "Orlando, FL",
        "publication_date": "2025-01-03"
    }
]