Large Eddy Simulation (LES)

Large Eddy Simulation (LES) is another important turbulent modeling approach. LES is a more computationally intensive technique compared to Reynolds-Averaged Navier-Stokes (RANS) models like 𝑘−𝜀 or 𝑘−𝜔.
In LES, the large turbulent structures in the flow are resolved directly, while the smaller scales of turbulence are modeled. This makes LES particularly suitable for capturing the unsteady, coherent turbulent structures present in many flows, such as those in turbulent boundary layers, wakes, and jets. LES is often used in simulations where accurate prediction of flow details and turbulence dynamics is critical, such as in complex flow configurations or where resolving fine-scale turbulent features is important.
Mesh size must be carefully considered when employing Large Eddy Simulation (LES) to determine the filter length, given that the smallest eddies to be computed primarily depend on the filter length or mesh size. However, due to the computational cost associated with resolving large turbulent structures, LES is typically applied to smaller-scale simulations or in cases where high-fidelity results are necessary.