Wall model for large eddy simulations accounting for particle effect
Wall model for large eddy simulations accounting for particle effect
Wall Modeling in Large Eddy Simulations (LES) with Particle Effects – A Turbulent Leap Forward
In computational fluid dynamics (CFD), Large Eddy Simulation (LES) is a powerful tool for resolving large-scale turbulent structures, but its accuracy near walls is limited by the high computational cost of resolving fine-scale eddies. To overcome this, wall models are introduced to approximate near-wall turbulence. Traditionally, these models focus solely on fluid behavior; however, real-world scenarios—ranging from environmental dust transport to industrial spray systems—often involve particle-laden flows, where the interaction between particles and turbulent boundary layers plays a critical role.
A wall model that accounts for particle effects introduces a paradigm shift in LES. In particle-laden turbulent flows, particles with inertia do not follow the fluid streamlines precisely. Instead, they interact with eddies, experience turbophoresis (migration toward walls), and can deposit or rebound depending on wall properties. These interactions affect both momentum and energy exchange near the wall. Ignoring these effects leads to inaccurate predictions of wall shear stress, particle deposition rates, and even heat/mass transfer.
Advanced wall models integrate two-way coupling, where both fluid affects particles and vice versa. These models also consider particle characteristics like size, density, and Stokes number to estimate wall-normal fluxes and turbulent diffusion. Such hybrid approaches enhance the fidelity of simulations in applications like combustion chambers, urban pollution modeling, and aerospace re-entry flows.
Ongoing research combines LES with Lagrangian particle tracking, augmented by machine-learning-informed wall functions or Reynolds-averaged background fields, to dynamically adapt to particle concentration and feedback effects. These techniques ensure computational efficiency while capturing essential near-wall physics.
As the demand for accurate, physics-based modeling of multiphase turbulent flows grows, particularly in aerospace, environmental, and process engineering fields, wall models with particle sensitivity are becoming essential. They not only improve simulation accuracy but also reduce computational burden, making LES accessible for complex, real-world applications.
Global Particle Physics Excellence Awards
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