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## Turbulence Properties, Conversions & Boundary Estimations

Properties
Freestream velocity U [m/s]
Turbulence kinetic energy k [J/kg] = [m^2 / s^2]
Turbulence dissipation ε [J/kgs] = [m^2 / s^3]
Specific turbulence dissipation ω [1/s]
Turbulence intensity/level Tu [%]
Turbulence length scale TuL [m]
Kinematic viscosity ν [m^2/s] (Air: 1.5e-05, Water: 1E-06 at room temp & pressure)
Eddy viscosity ratio μt / μ []
Color codings:
 Source Target Error
Conversions
ω from k and ε using β* = Cμ = 0.09, see the definition of ω for formula used
ε from k and ω using β = Cμ = 0.09, see the definition of ω for formula used
Turbulence variables (k, ε, ω) from turbulence intensity (Tu), length-scale (TuL) and freestream velocity (U∞)
Turbulence variables (k, ε, ω) from turbulence intensity (Tu), eddy viscosity ratio (μt/μ), freestream velocity (U∞) and kinematic viscosity (ν)
Turbulence intensity (Tu) from turbulence kinetic energy (k) and freestream velocity (U∞)
Turbulence length scale (TuL) from turbulence kinetic energy (k) and dissipation (ε)
Turbulence length scale (TuL) from turbulence kinetic energy (k) and specific dissipation (ω)
Turbulence eddy viscosity ratio (μt/μ) from turbulence kinetic energy (k) and dissipation (ε)
Turbulence eddy viscosity ratio (μt/μ) from turbulence kinetic energy (k) and specific dissipation (ω)
Warning!

Some codes (Fluent, Phoenics and CFD-ACE for example) use a different definition of the turbulence length scale than the conversion formulas used above. See the CFD-Wiki page on turbulence length scale for more information.

Boundary Estimations
Turbulence intensity: