Work

Physics-based distinction of nonequilibrium effects in near-wall modeling of turbulent separation bubble with and without sweep

Year: 2025

Type: article

Abstract: Three-dimensional turbulent boundary layers subject to pressure gradients and undergoing separation remain a key challenge for wall modeling. Using DNS datasets of swept and unswept separation bubbles, this study employs the Renard--Deck skin-friction decomposition to isolate and analyze nonequilibrium contributions critical to near-wall modeling. Wall-modeled LES demonstrates that only wall models capturing the spatial growth term accurately reproduce the true energy balance in nonequilibrium zones. The analysis highlights when and why nonequilibrium effects must be incorporated, providing physics-based guidance for improving wall model predictions in practical flows.

Source: Physical Review Fluids

DOI: 10.1103/gfr7-6l2m

Authors: Imran Hayat, George Ilhwan Park

Institution: University of Pennsylvania

Language: English

Topic: Fluid Dynamics and Turbulent Flows

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: National Aeronautics and Space Administration, Purdue University, Aeronautics Research Mission Directorate, Office of Naval Research

Awards: G3473581158, G3722264257, G4590548100