Summary Chart of Incompressible Flow Turbulence Models
Introduction
• Here is a chart showing some of the major characteristics of turbulence models.
• The order is from least complex to most complex.
• For simplicity, consider incompressible flow without buoyancy, but the flow is three-dimensional.
• Direct numerical simulation is included for completeness, even though it is not a turbulence model.
Model Number of additional
transport equations Assumptions/Approximations
Algebraic models
(zero-equation models)
0
One-equation models
1
Two-equation models
2
Algebraic Reynolds
stress models (ASM)
2
Reynolds stress models
(RSM)
7
Large Eddy Simulation
(LES)
either 0 (algebraic
equations) or 1
(transport equation) for
the smallest scales
Direct Numerical
Simulation (DNS)
0
Mixing length
Boussinesq eddy viscosity model,
turbulent
2
32
ij i j ij e ij
uu K E
τρ ρδμ
=− ≈− +
Nonlinear extension of Boussinesq eddy
viscosity model,
turbulent
2
32
ij i j ij e ij
uu K E
τρ ρδμ
=− ≈− + +
additional higher order terms
Solve for ensemble-averaged quantities only (no
details about time-dependent turbulence quantities)
Model small-scale
turbulence only
Exact time-dependent
solution of large scales
Exact - model all scales of
turbulence (small to large)
docsity.com