Turbulence Intensity & k-epsilon BCs

Compute inlet k, epsilon, and omega from turbulence intensity.

visual calculatorTurbulence & Wall Modeling

Read the flow shape before trusting the number.

This page turns a CFD setup into regime, scale, and dominant-effect cues. Adjust the calculator below and compare the moving graphic with the computed result.

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turbulenceboundary conditionOpenFOAMk-epsilon

formula

KaTeX rendered

\begin{aligned}\text{k = 1.5 (I U)\^{}2}\\[0.35em]\text{epsilon = Cmu\^{}(3/4) k\^{}(3/2) / l}\end{aligned}

ASCII source

k = 1.5 (I U)^2, epsilon = Cmu^(3/4) k^(3/2) / l

I — turbulence intensity (%)U — mean velocity (m/s)D — length scale (m)

k (m²/s²)

0.3750

ε (m²/s³)

10.7810

ω (1/s)

319.44

ℓ (m)

0.0035

Use k, ε, ω as inlet BCs for k-ε / k-ω SST in OpenFOAM / Fluent. I ≈ 1–5% for internal, 0.05–1% for external flows.

turbulence boundary condition OpenFOAM k-epsilon