Keywords :
Diffusion model; Direct-numerical-simulation; Energy spectrum; Flow problems; Homogeneous isotropic turbulence; Large-eddy simulations; Length scale; Memory efficient; Turbulent inflow conditions; Turbulent kinetic energy; Computational Mechanics; Condensed Matter Physics; Mechanics of Materials; Mechanical Engineering; Fluid Flow and Transfer Processes; Physics - Fluid Dynamics
Abstract :
[en] The present research proposes a new memory-efficient method using diffusion models to inject turbulent inflow conditions into large eddy simulation and direct numerical simulation for various flow problems. A guided diffusion model was trained on decaying homogeneous isotropic turbulence samples, characterized by different turbulent kinetic energy levels and integral length scales. Samples generated by the diffusion model accurately reproduce turbulence statistics, such as the energy spectrum and the two-point autocorrelation functions, while preserving the ability to generate instantaneous three-dimensional velocity fields with detailed fluctuations. Physical representativeness is also evaluated by injecting the synthetic samples into a free domain (i.e., without any wall boundary) through an inlet boundary condition. The method demonstrates promising results regarding energy spectrum, spatial correlation, turbulent kinetic energy level, and integral length scales without increasing the development distance as compared to a library-based method.
Funding text :
The ARIAC Project (No. 2010235) funded by the Service Public de Wallonie (SPW Recherche) is gratefully acknowledged for funding this research. The present research benefited from computational resources made available on Lucia, the Tier-1 supercomputer of the Walloon Region, infrastructure funded by the Walloon Region under the Grant Agreement No. 910247.
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