手法を比較

	Reynolds-Averaged Navier-Stokes	剥離渦シミュレーション
分野	流体力学	流体力学
系統	Process / pipeline	Process / pipeline
提唱年	1895	1997
提唱者	Osborne Reynolds	Philippe Spalart
種類	Computational turbulence modeling approach	Hybrid turbulence modeling approach
原典	Reynolds, O. (1895). On the dynamical theory of incompressible viscous fluids and the determination of the criterion. Philosophical Transactions of the Royal Society A, 186, 123-164.	Spalart, P. R., Jou, W. H., Strelets, M., & Allmaras, S. R. (1997). Comments on the feasibility of LES for wings, and on a hybrid RANS/LES approach. Advances in DNS/LES, 1, 4-8.
別名	RANS, Reynolds-averaged flow simulation	DES, hybrid RANS-LES
関連	5	5
概要	The Reynolds-Averaged Navier-Stokes (RANS) equations represent a time-averaged form of the Navier-Stokes equations developed by Osborne Reynolds in 1895. This approach decomposes turbulent flow into mean and fluctuating components, enabling practical simulation of turbulent flows by modeling turbulent stresses rather than resolving all scales. RANS remains the most widely used computational fluid dynamics method in engineering applications due to its computational efficiency.	Detached Eddy Simulation (DES) is a hybrid turbulence modeling approach introduced by Spalart in 1997 that combines the computational efficiency of RANS in attached boundary layers with the accuracy of LES in separated wake regions. By automatically switching between RANS and LES based on local grid spacing and turbulence length scales, DES provides superior predictions for flows with large separations, shear layers, and vortex shedding at a cost between pure RANS and pure LES. DES has become the standard method for complex aerospace applications involving separation and transient phenomena.